if TS - VW Division of Agricultural Sciences UNIVERSITY OF CALIFORNIA CALIFORNIA AGRICULTURAL EXPERIMENT STATION BULLETIN 784 Alfalfa hay is one of the principal livestock feeds in the state of California. Yet, the quality of marketed alfalfa varies considerably. Producers and purchasers, who fre- quently evaluate alfalfa visually, need more accurate criteria for judging quality. This paper suggests various means of measuring and controlling alfalfa quality. The research summarized in this bulletin was a cooperative effort of the Departments of Agronomy, Animal Husbandry and Agricultural Engineering. Many of the experi- ments have been reported in individual scientific papers cited at the end of this bulletin but will be summarized in conjunction with new information not previously reported. The individual investigators responsible for the research reported in this bulletin are L. G. Jones, Agronomy; H. Heitman, J. L. Hull, G. P. Lofgreen, J. H. Meyer and W. C. Weir, Animal Husbandry; and J. B. Dobie, J. R. Goss and R. A. Kepner, Agricultural Engineering. The technical assistance of W. J. Clawson in collection of data is gratefully acknowledged. Part of the data was obtained by G. T. Clark, J. W. Clawson, R. L. Gaskill, F. K. Hart, B. Silver, G. S. Stoewsand, and A. Strother in partial fulfillment of the Master of Science degree. Publications of these investigators which were utilized in the preparation of this bulletin are listed under "References" on page 71. CONTENTS The Findings in Brief 3 Variations in Alfalfa Quality in California 7 Lignin and Protein — Indicators of Quality 8 Stage of Maturity — Effect on Quality 9 Location — Effect on Quality 33 Season — Effect on Quality 37 Variety — Effect on Quality 38 Alfalfa Aphid Damage 39 Forage Type — Effect on Quality 39 Harvesting and Processing Methods — Effect on Quality 44 Time and Level of Supplementation — Effect on Quality 56 Chemical Evaluation 59 References 71 THE AUTHORS James H. Meyer is Associate Professor of Animal Husbandry and Associate Animal Hus- bandman in the Experiment Station, Davis. Luther G. Jones is Specialist in the Experiment Station, Department of Agronomy, Davis. MARCH, 1962 J THE FINDINGS IN BRIEF A comprehensive study was made of various factors affecting alfalfa as a . livestock feed. 1 From a series of diges- tion, growth and fattening experi- ments with cattle and sheep, lignin, 2 crude fiber and crude protein were found to be good indicators of the feed value of alfalfa as an energy source. Following this, chemical composition and animal experiments were used to establish principles and methods for best utilization of alfalfa. Lignin content — an indicator of alfalfa quality As alfalfa matures, lignin, which re- tards cellulose digestion, increases dur- ing the prebud and bud stages. A marked change occurs, however, at the onset of flowering. When the hay is in 10 per cent bloom the rate of lignin formation decreases, and lignin re- * mains relatively constant or increases much more slowly to full bloom. The response of sheep and cattle in experi- ments over a four-year period con- firmed that feed quality decreases as lignin increases. Bud stage hay was superior to alfalfa cut in flower. Ten per cent bloom stages sometimes re- . sembled bud stage hay and at other times resembled the more advanced bloom stages. The quality of alfalfa remained constant after 30 per cent bloom. Lambs responded to differences in stages of maturity although swine did not. Apparently, since pigs do not util- ize cellulose, they were unaffected by increased lignin content in mature hay. While we demonstrated that highest quality alfalfa was produced from the immature stages, nevertheless, a con- r sideration of yield and stand survival Submitted for publication April 7, 1961. 2 Lignin is a fibrous compound formed as a plant approaches flowering. It binds cellulose so that much of it is not available for diges- tion by ruminants. may indicate that production is greater at a more mature stage. When only one major cutting of alfalfa was realized, yields of dry matter, total digestible nutrients or lamb per acre were greater at 50 per cent bloom. No advantage resulted in allowing the alfalfa to go to full bloom. The optimum maturity stage — 10 per cent bloom Assessing yield in terms of total di- gestible nutrients or dry matter for a season of many cuttings indicated that either 10 or 50 per cent bloom alfalfa produced the maximum yields. Con- versely, lamb production indicated lit- tle difference between 16 per cent bud and the more mature stages. The 16 per cent bud alfalfa was more diges- tible, resulting in increased feed intake and better utilization of total diges- tible nutrients after absorption. The animals ate relatively more than was required for maintenance and so gained more weight. Though it has been shown that bud stage hay is a superior feed and produces as much or more lamb per acre, greater invasion of weeds, depletion of root reserves and increased number of cuttings needed per season tend to rule out this maturity stage. Ten per cent bloom produced yields of lamb as great as that produced by bud stages, required fewer cuttings, and had adequate root reserves. Fur- ther, 10 per cent bloom alfalfa was more digestible and produced greater weight gains than more advanced stages. This stage, therefore, was shown to be the optimum stage for harvesting alfalfa. Determining 10 per cent bloom While maturity of alfalfa is most commonly described by flowering stage, it is not always possible to use this system because flowering may be [3] masked by insect damage, disease and season. Crown buds and regrowth were a satisfactory substitute. Sixteen per cent bud alfalfa showed buds on 10 to 45 per cent of the crowns; with 10 per cent bloom, regrowth averaged from 0.5 to 0.75 inch on 50 to 75 per cent of the crowns; and with 50 per cent bloom, regrowth averaged from 1.25 to 2 inches on about 80 per cent of the crowns. These guides seemed to hold for all varieties and areas of the state. A further search for some physical measure of quality revealed that height of stand, irrespective of matur- ity stage, year, or cutting was corre- lated with lignin content and hence quality. This was established by the response of sheep and cattle. A high correlation was also found between height and lignin or protein content of alfalfa collected in a state-wide survey. Having established that 10 per cent bloom is, from most standpoints, the desirable time to harvest alfalfa, the table below summarizes the methods for determining 10 per cent bloom. Harvesting schedule, geographical location, and season — effect on alfalfa quality Variability of alfalfa hay was in- creased when a set number of days be- tween harvesting was used (calendar basis), even though this simplifies the management of men and machinery. HOW TO DETERMINE 10 PER CENT BLOOM ALFALFA From blossoms: Cross the field, selecting at random be- tween the levies a few major culms at a time, and then count the number of culms with one or more blossoms. Ten per cent bloom means that 10 per cent of the stems selected at random has one or more blossoms. From crown buds and regrowth: Ten per cent bloom is also indicated when 60 per cent of the crowns has buds of regrowth which average 0.75 inch. From height of plant, lignin and crude fiber content: Modified County Height* Lignin t crude fiber t inches per cent per cent Shasta 26.4 6.9 23.8 Yolo 28.6 6.8 23.5 Stanislaus, sandy soil 19.2 6.4 22.3 Stanislaus, heavy soil* 25.0 6.9 23.8 Monterey 21.0 6.3 21.9 Fresno 21.0 6.8 23.5 Kings 19.0 5.6 19.7 Kern 24.0 6.9 22.3 Los Angeles § 23.0 6.5 22.6 Imperial, sandy soil 18.6 5.6 19.7 Imperial, medium soil 16.4 5.3 18.8 Imperial, heavy soil 17.1 5.3 18.8 * Average height measured between levies at random across the field. t Analysis before harvest. t Tracy area. § Antelope Valley. [4] Geographical location in California influenced quality of alfalfa at the same maturity stage. Considering the various measures, higher quality al- > falfa was produced in Imperial and Palo Verde Valleys. The old Tulare Lake Bed region of Kings County and the Lancaster area of Los Angeles County produced alfalfa slightly lower in quality. The other areas in the Cen- tral Valley, Monterey County and the Fall Creek area of Shasta County pro- duced alfalfa which was lower in qual- ity. It was shown, however, that ma- turity stages can be manipulated to produce equivalently high quality alfalfa from all areas of the state. In » some areas, particularly Imperial Val- ley, alfalfa was higher in quality when grown on heavy clay soils. Tempera- ture did not seem to be related to quality. Varieties of alfalfa did not dif- fer in quality when compared within any one area. Season of the year, considering the state as a whole, had a distinct effect on the quality of alfalfa within ma- turity stages. Three definite periods were found: in January and February (in Imperial Valley only) alfalfa was lowest in lignin and highest in protein; March through June was the second period, when alfalfa had an average lignin content of 5.8 per cent and an estimated preharvest TDN of 64 per cent; the third period, when alfalfa was lowest in quality, was July to Oc- tober. Lignin rose to 6.8 per cent and , the estimated preharvest TDN was 61 per cent. Forage type — effect on quality How alfalfa is utilized by animals is important for maximum economical production. With the pasturing method, the animals, through selective grazing, consumed a more nutritious forage than they consumed under the soiling or haying methods. The ani- mals fed soilage or hay attempted to overcome the lower nutritive value by consuming more dry matter per day. This sometimes allowed the soilage animals to equal the gains of the pas- tured animals. One-day rotational or strip grazing did not show a practical advantage when compared to 6- or 7-day rota- tional grazing. Even though forage consumed from soiling was of lower value, the greatest production per acre was realized by soiling because the animals did not damage or refuse forage in the field as did the pastured cattle. As a result of the mechanics of processing hay, it was lower in quality than soilage and pas- ture but was intermediate in produc- tion per acre — less than soilage but greater than pasture. Selective grazing was more apparent on a tall, sparse-growing plant (alfalfa) than on a low, dense forage (trefoil- orchardgrass). Dry matter yields did not correctly appraise the relative value of various forages; the response of animals was needed to assess nutri- tive value and to gauge the influence of selective grazing. Harvesting methods — effects on quality Dehydrating alfalfa was the harvest- ing procedure resulting in the highest quality hay because the alfalfa was taken directly from the field with little or no loss of nutrients. Lignin was lower in the dehydrated hay than in the field-cured hay, indicating that field-curing induced a loss of lower- lignified material (leaves and fine stems). Dehydrated hay produced gains that were significantly greater than the gains of sheep fed field-cured hay. Most of the increased value of the dehy- drated hay was the result of increased nutritive content rather than increased palatability. The greatest advantage in dehydrating resulted in the prevention of rain damage. [5] Crushing or crimping alfalfa imme- diately after mowing (conditioning) re- duced curing times by two days com- pared to times required for uncondi- tioned hay. No consistent advantage of conditioning was found in three feeding experiments with sheep. Con- ditioning adds to the costs and prob- lems of an extra operation with a spe- cial piece of equipment. Since feeding response was not obtained, condition- ing would be justified only if it pre- vented crop damage during bad weather, if it improved the scheduling of operations, or saved time or labor. Studies were made on nutrient loss in haymaking when the raking and baling were done after the hay was too dry. Even though the weight gains of lambs fed the hay were reduced and the net energy content decreased be- cause of mismanagement procedures, the greatest effect was on yield per acre. The most severe loss occurred when alfalfa was raked too dry — 28 per cent of the nutrient yield was lost — while baling too dry caused only a 5 per cent loss if the hay had been raked correctly; however, if the alfalfa had previously been raked when dry, the nutrient loss was 16 per cent over and above the raking losses. Processing and feeding methods — effects on quality Alfalfa hay can be processed and fed to sheep and cattle in many different forms — long, chopped, pelleted and wafered — and a different feeding re- sponse might be expected from each form. Long hay shows distinctly the leaves and stems, while chopping and, particularly, fine grinding make it al- most impossible to distinguish leaves and stems. Long hay, therefore, can be selectively eaten and certain portions refused. Chopping can reduce selec- tion and force consumption of more of the lignified stemmy portions, while pelleting completely eliminates feed refusal caused by selection. Grinding and pelleting hay resulted in greater consumption, and hence greater gains and efficiency of feed util- ization because a large portion of the hay was used for gain rather than for maintenance. Pound for pound, pel- leted hay was equal in feed value to chopped hay when equal quantities were consumed, digestibility was about the same, and net energy content was the same. Increased rate of digestibility in the rumen, resulting in faster feed passage through the digestive tract, was shown to be responsible for the greater feed intake when animals were fed finely ground hay. Generally, when 50 to 60 per cent concentrate was included in the pel- leted ration, there was little or no in- crease in either feed consumption or gain. In fact, pelleted, high-concen- trate rations sometimes resulted in a reduced feed intake as compared to milled rations. The addition of thirty per cent concentrate to pellets seemed to be the upper limit resulting in a feeding response. Calculations from chemical analysis indicated that, at present, 21 per cent crude fiber should be the lower limit. Hay compressed into wafers but not finely ground was about equal to chopped hay in feeding value but did not bring about the increased feed in- take and weight gain produced by pel- leted hay. Supplements to alfalfa ration — effects on animal gains, dressing percentage, and carcass grades Earlier studies have compared the production of nutrients and of beef and lamb from alfalfa harvested by various methods. Although relatively good gains can be achieved on high- quality alfalfa in the form of soilage or 6] hay as the sole source of feed, it is well recognized that an additional source of energy is needed to produce a well- finished animal with a high dressing percentage and a high-grading carcass in a reasonable feeding period. It was shown in one study that barley, fed at the rate of 1 pound per 100 pounds body weight to steers receiving alfalfa soilage, brought about an increased daily gain of approximately 0.5 pound. Molasses alone was shown to be unsat- isfactory as a supplement to alfalfa soilage. Other observations have shown a mixture of barley and molasses and dried beet pulp to be a satisfactory sup- plement to both alfalfa soilage and hay. Gains by steers continuously supple- mented with concentrate (barley and beet pulp) represented more energy than gains of those not supplemented or supplemented for only the last half of the experiment. This occurred even though weight gains were the same. Variations in the quantity of concen- trate supplementation produced a sim- ilar result. Weight gains did not in- crease above a certain amount of sup- plementation but energy gains did in- crease, resulting in higher yield and carcass grade. Chemical analysis for crude fiber — an indicator of quality A method has been proposed for a critical evaluation of alfalfa hay qual- ity by the use of chemical analysis for crude fiber and moisture. Knowledge of the crude fiber allows a prediction of the total digestible nutrient and di- gestible protein content. From this, ra- tions for livestock can be more ade- quately designed. Furthermore, tables were prepared, utilizing the net energy system, which allow farmers to calcu- late the monetary value of alfalfa rela- tive to the price of barley and cotton- seed meal. Crude fiber has also been shown to be highly correlated to palat- ability of hay — the lower the fiber the higher the palatability. VARIATIONS IN ALFALFA QUALITY IN CALIFORNIA Alfalfa hay, a major component of »■.■*#■ livestock rations, is the most important Tc,ble 1 ' Composition of Some high-quality roughage in California. Alfalfa Hays Sold on the Los Its quality varies, however (table 1). Angeles Market* It is apparent from this table that visual estimates (Federal Grade) of hay quality are unreliable, and that more reliable gauges of quality are needed. Although hay is one of the most vari- able livestock feeds, it is one of the highest yielding crops, one of the most economical feeds, and an important source of energy, protein, minerals and vitamins for livestock. Livestock growers, therefore, Would benefit * These data were obtained by W. M. Cory, Farm , . r t • t ,. Advisor in Orange County, California. greatly if a consistent, high-quality t Air-dry basis, product could be guaranteed. Hay lot number Federal grade Water Proteinf Ashf per cent 1 2 3 4 5 19.3 14.6 11.8 11.8 11.1 19.7 17.7 15.3 11.7 13.7 10.8 9.7 8.1 9.7 12.0 7] LIGNIN AND PROTEIN— INDICATORS OF ALFALFA QUALITY While the ultimate test of hay qual- ity is animal response (growth, fatten- ing or milk production), a simple chemical analysis can give some indica- tion of the nutritive value of proposed rations. Such an analysis would aid re- search on hay quality and could also be used to control the quality of mar- keted hay. In these studies various chemical components of alfalfa were analyzed, after which the quality of the hay was tested by animal response. Forty-three different samples of al- falfa hay with great variation in qual- ity, fed in 198 digestion trials, were 3 A modification of the A.O.A.C. (1955) pro- cedure. To make this analysis follow this pro- cedure: After a 30-minute refluxing with boiling NaOH, filter through a weighed Gooch or fritted disc crucible and wash with studied (table 2). Lignin, crude fiber, or a modified crude fiber 3 were highly correlated with total digestible nutri- ents (TDN), while crude protein was not as highly correlated. Further cal- culations indicated that digestible pro- tein could be predicted from the lig- nin or crude fiber content (table 2) with a high degree of accuracy. A very high correlation coefficient (0.99) ex- isted between crude protein and di- gestible protein. When only one analysis can be used to predict total digestible nutrients (TDN) and digestible protein, analysis boiling water followed by ethanol. Dry and weigh the crucible and residue. The difference between the total weight and the weight of crucible is the "crude fiber plus silica." See Meyer and Lofgreen, 1959, for details. Table 2. Regression and Correlation of Alfalfa Constituents with Total Digestible Nutrients and Digestible Protein* Constituent Regression equation! Standard error of the estimate Correlation coefficient Total digestible nutrients Lignin Y = 79.1 - 2.67X Y = 78.7 - 0.8027X Y = 81.07 - 0.8558X Y = 1.142X + 33.33 3.13 2.84 2.52 3.41 -0.84t -0.87J -0.89J +0.80J Crude fiber Modifed crude fiber Crude protein Digestible protein Lignin Y = 30.6 - 1.21X Y = 29.5 - 0.5168X Y = 30.7 - 0.5416X Y = 0.9155X - 3.1 1.94 1.95 1.89 0.63 -0.85} -0.85| -0.86J +0.99J Crude fiber Modified crude fiber Crude protein * Digestion trials conducted on 43 different samples of alfalfa hay. •t j equals tota * di £ estiDl e nutrients or digestible protein, as the case may be; X equals lignin, crude fiber, modified crude fiber or protein, as the case may be. All results are reported on an oven-dry basis. t Indicates statistical significance (0.01). [8] Table 3. Regression and Correlation of Alfalfa Constituents with Weight Gain of Lambs* Year Number of samples Regression equationf Standard error of the estimate Correlation coefficient Lignin 1955 6 8 7 9 Y = 0.5066 - 0.0344X Y = 0.6540 - 0.0447X Y = 0.6487 - 0.0516X Y = 0.8973 - 0.0671X 0.002 0.032 0.019 0.019 -0.99 1 1956a 1956b 1958 -0.80§ -0.94} -0.93| Crude protein 1955 6 Y = 0.155 + 0.0079X 0.014 0.96} 1956a 8 Y = 0.0158X - 0.024 0.030 0.83 § 1956b 7 Y = 0.0170X - 0.110 0.019 0.94} 1958 9 Y = 0.0120X - 0.130 0.040 0.64 * Weight gain of lambs fed alfalfa in which the weight gains were adjusted to equal feed consumption in an analysis of covariance. The 1955, 1956a and 1958 trials were conducted with pelleted alfalfa, whereas the hay was chopped in the 1956b trials. t Y equals adjusted weight gain and X equals lignin or protein content on an oven-dry basis. X Indicates statistical significance (0.01). § Indicates statistical significance (0.05). of the fiber constituents is more accu- rate. While protein analysis predicted digestible protein more accurately, fiber analysis was superior in predict- ing TDN, an energy measurement of more importance than digestible pro- tein. Of the two constituents, lignin and protein, lignin more often indicated quality as measured by liveweight gains of lambs (table 3). The weighted average of adjusted daily gains corre- lated with lignin content was -0.94; correlated with protein content it was 0.85. Both of the correlations are high. Lignin content (or other fiber fractions closely following lignin changes) is a more reliable gauge of alfalfa quality than protein content because lignin it- self has a direct effect on cellulose utili- zation. In addition, rain damage (pres- ent in the 1958 trials reported in table 3 and table 39) increased both lignin and protein while soluble constituents were leached. Since protein was posi- tively correlated with measures of energy value, analysis for it after rain damage gave aberrant results. STAGE OF MATURITY— EFFECT ON QUALITY How stage of maturity affects the feeding value of alfalfa, measured by such criteria as weight gains or milk production, is not well established. Weather, in past research, often inter- fered with a well-designed experiment, or results were inconclusive because at times hay harvested by various means was not obtained from the same cut- ting, field, or even area. In addition, the systems used in describing maturity stages were very seldom accurately de- fined. The major goals of the research reported here were: (1) to relate 9] quality as denned by animal response to stage of maturity, (2) to define more accurately the various stages of ma- turity as guides to quality, and (3) to relate chemical and physical character- istics (lignin and protein content, inci- dence of flowering, height and occur- rence of regrowth, and height of plant) to quality and stage of maturity. Relation of flowering to quality and yield Influence of stage of maturity on chemical composition. Stage of ma- turity was determined by hand-count- ing the number of stems in a certain stage. For example, 10 per cent bloom means that 10 per cent of the stems selected at random across the test field had one or more blossoms. Samples for chemical analysis were taken daily by random selection of growth (including any regrowth) at mower height (2 inches) until the sample weighed about 1 kilogram. Each sample was dried overnight on a tray in a forced-draft 16 *J V, 12 8 4 jjf~-- Figure 1. An alfalfa stem is considered in blossom if only one blossom shows, as on the stem on the left, or if many blossoms show, as on the second stem from the left. A stem is considered in bloom even if the bud or blos- som has been damaged. The two stems on the right are examples of previously damaged buds; the blossoms are missing but they must still be counted as being in bloom. oven at 70 °C and then ground for laboratory analyses. The samples were analyzed for lig- nin, an element which is indigestible and interferes with cellulose digestion. Daily sampling and analysis of the stand of alfalfa (figures 2 and 3) indi- cated a gradual increase in lignin dur- ing the prebud and bud stages with the most marked change at the onset of flowering. The accumulation of lignin leveled when the alfalfa reached approximately 10 per cent bloom, re- maining relatively constant or increas- ing much more slowly after that. Results from different years agreed relatively well on this point, even though similar maturity stages did not always occur on the same date. Weather and season, for example, influenced plant physiological age dif- ferently each year so that more or less time was required for a plant to reach a certain stage of growth. Because of this, a physiological measure of ma- turity stage, such as flowering or re- growth, is preferable to measurements of time intervals. Quantitatively, lig- nin content of the 1955, 1956 and 1958 spring cuttings (the second in this area) agreed remarkably well. How- ever, the lignin content of the August 1958 cutting (the fourth) became con- stant at about the 10 per cent bloom stage and was not as high as that of other cuttings or years. Nonetheless, it appears that physiological measures of maturity such as hand-counting stems in bud or blossom indicates , quality if lignin is the criterion. Holocellulose followed a pattern similar to that of lignin but was more irregular. Holocellulose contains all the types of cellulose and is quite di- gestible when not lignified. In general, protein content de- creased in the stand, with a curve in- verse to lignin. A change was marked at the onset of flowering, but not as marked as the change in lignin. The 10 COMPOSITION OF ALFALFA- 1955 COMPOSITION OF ALFALFA- 1956 PROTEIN 25 27 29 31 2 MAY 10 12 14 16 18 20 JUNE 12 14 16 18 20 22 24 26 28 30 MAY Figure 2. Changes in alfalfa chemical composition with advancing maturity, 1955 and 1956, Davis, California. 3 5 7 JUNE COMPOSITION OF ALFALFA — 1958 38 —I 1 1 1 1 1 1 » i I 1 l PROTEIN 35 32 29 26 - ^-\>^ /> . 23 "^^^^ 2U LIGNIN PROTEIN H — I — I — I — I — I — \- -\ 1 1 1 1 1- 17 19 21 23 25 27 29 31 2 4 6 8 10 12 3 5 7 9 II 13 15 17 19 21 23 25 27 29 31 MAY JUNE AUGUST Figure 3. Changes in alfalfa chemical composition with advancing maturity, 1958, Davis, California. [ii] amount of protein in the stand showed remarkable agreement between years except that quantities were greater in the prebud stages of 1956. A summary of the composition of 16 per cent bud, 10 per cent bloom and 50 per cent bloom alfalfa from figures 2 and 3, presented in table 4, shows again a marked change from the bud stage to 10 per cent bloom. The increase in lignin or decrease in protein was not as great between 10 per cent and 50 per cent bloom as be- tween bud and 10 per cent bloom alfalfa. The purpose of the investigation reported in table 5 was to determine how applicable the results of the ex- tensive studies made at Davis (figures 2 and 3) were to other areas in Cali- fornia. Alfalfa was obtained from three maturity stages — 16 per cent bud, 10 per cent bloom and 50 per cent bloom — from each cutting in 13 different geographical areas with great variation in environment. These re- sults show the same characteristic change in lignin and protein content found in the Davis studies, even though there was some variation be- tween areas. Most areas revealed a marked lignin increase when alfalfa advanced from bud to the 10 per cent bloom stage and showed less increase from 10 to 50 per cent bloom. As in the Davis study, lignin reached a plateau in many instances when 10 per cent bloom occurred. In other instances lignin continued to increase from 10 per cent bloom on, but at a decreased rate (figure 4). Effect of stage of maturity on al- falfa hay quality as measured by digestibility. In 1955, alfalfa harvested at six stages of maturity (figure 2) and fed to growing and fattening sheep was evaluated in a digestion trial. Wethers in a 6 x 6 Latin square design were employed. Seven-day preliminary periods with 7-day collection periods were used. The digestion coefficients for or- ganic matter, protein, the true digesti- bility of the protein (corrected for metabolic protein in the feces) and the total digestible nutrients of the alfalfa cut at the six stages are presented in table 6. The digestibility of the organic Table 4. Composition of Various Maturity Stages, Davis Ligninf Proteinf Year 16 per cent bud 10 per cent bloom 50 per cent bloom 16 per cent bud 10 per cent bloom 50 per cent bloom per cent 1955 5.6 6.0 5.6 5.2 5.6 7.8 6.4 7.0 6.9 6.6 7.8 7.4 7.8 7.6 7.0 26 26 28 25 23 20 26 24 21 21 18 1956 21 1957 22 1958, May 19 1958, August 20 Mean 5.6 6.9 7.5 26 22 19 Estimated TDNJ 64.1 60.7 59.1 * Summary of figures 2 and 3. t Dry-matter basis. X Total digestible nutrients. See table 2. [12] 8 U +■ 3 O X U) D o (A o TO b OC>00 00O0-QT3 & a a.o.n.o.O'OXi.c.Q.o u e. 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Response of Steers Fed Sun-Cured Alfalfa Harvested at Three Maturity Stages, 1955* Measurements Alfalfa maturity stage Bud 10 per cent bloom 50 per cent bloom Alfalfa composition Height of stand, inches Composition: Lignin, per cent Crude protein, per cent Steer response Number per lot Initial weight, pounds Daily gain, pounds Daily feed consumed : Barley, pounds Alfalfa, pounds Gain per 100 pounds feed consumed, pounds Carcass data Dressing per cent Carcass fat, per cent Grade : Good, number Standard, number 42 8.1 16.0 12 12 873.0 875.0 1.48 1.11J 4.4 4.4 17.0 15.8 6.9 5.5 iot 838.0 1.12J 4.4 15.7 5.6 59 59 20 19 5 7 7 5 57 18 9 1 * All results reported on a dry-matter basis. t Two steers removed because of sickness. j Statistically significant difference (0.05) . ence was apparent between the 10 and 50 per cent bloom stage hay even though lignin was higher and protein lower in the 50 per cent bloom stage hay. In general the growth studies with sheep and steers and the digestibility studies with sheep were in agreement with what might be expected from the chemical composition, particularly as related to lignin. It appears that the 10 per cent bloom stage was the critical turning point in feeding value. After 10 per cent bloom, the increase in lignin or decrease in daily gains of lambs fed this hay was not as great as that found between the bud and bloom stages. From lamb response, hay harvested at the 10 per cent bloom stage sometimes resembled bud stage hays and at other times resembled the more advanced bloom stages. Effect of stage of maturity on al- falfa hay quality as an energy source for swine. Alfalfa harvested at the first three stages of maturity in 1956 (table 9) was also fed to swine to investigate whether stage of maturity influenced quality of alfalfa as an energy source. Each stage of maturity, 16 per cent bud, 3 per cent bloom and 34 per cent bloom, was fed in a factorial de- sign at three levels (5, 20 and 40 per [21 cent) and as dehydrated, sun-cured al- falfa or reground pelleted, dehydrated alfalfa. Since no significant interactions were found, the data were combined and summarized in table 13 for the stage of maturity effects. Stage of ma- turity was without effect, as evidenced by equal gains, feed consumption and backfat thickness (indicator of fat con- tent). Since the stage of maturity did af- fect weight gains of lambs fed the same alfalfas (table 9), apparently lig- nification mainly affects the utilization of cellulose, a component not readily digested by pigs. This comparison of swine and sheep indicates that lignin does not affect the energy nutrients available to swine. The evidence indi- cates that lignification influences hay quality primarily in cellulose avail- ablity to ruminants. Influence of stage of maturity on yield of dry matter, on total digestible nutrients and on lamb gains. While we have demonstrated that highest quality alfalfa was produced from the immature stages, nevertheless a con- sideration of yield and stand survival may indicate greater production per acre from the more mature alfalfa. Yield of the alfalfa fed in 1955 (table 8), presented in figure 5, illustrates two points that should be considered in assessing the effect of stage of ma- turity on yields: first, the yield from a single cutting versus seasonal yields, and second, the method used to meas- ure and evaluate yield. Alfalfa harvested at 50 per cent bloom from one cutting yielded maxi- mum amounts of dry matter, TDN or lamb per acre, and there was no ad- vantage in allowing the alfalfa to go to full bloom. In areas where only one cutting is expected, and particu- larly where early rains are more preva- lent than late rains, the 50 per cent bloom stage would be the stage of choice for cutting. Assessing yield in terms of TDN or Table 13. Response of Swine Fed Alfalfa Hay Harvested at Three Maturity Stages*! Alfalfa maturity stage Measurements 16 per cent bud 3 per cent bloom 34 per cent bloom Alfalfa composition Lignin content, per cent 6.1 25.1 6.6 25.2 7.8 Protein content, per cent 20.6 Swine response Number of pigs 27 1.24 5.40 1.23 1.0 27 1.23 5.03 1.24 0.9 27 Daily gain, pounds 1.25 Feed consumed, pounds 5.32 Adjusted daily gain, pounds 1.25 Backfat thickness, inches 0.9 . J^S 3 initial weight averaged 68 pounds; they were fed for an average of 60 days. Basal ration was 5 per cent alfalfa meal, 73.75 per cent barley, 7.5 per cent meat and bone scrap, 6.5 per cent soybean meal, 6.5 per cent cottonseed meal, 0.5 per cent NaCl and 20.5 grams of ZnSO, per 100 pounds. Antibiotics were added. Alfalfa replaced the barley when brought up to 20 and 40 per cent. f- Three replicates of 5, 20 and 40 per cent alfalfa in the rations were used for each maturity stage. Since no interaction was present, data were combined. 22 I7,000| — 8,500 16,000 15,000 14,000 > » [l3,000 > > "12,000 > a. > >: 1 1,000 £ 6,000* 5 s g" 5,000 4,000 3,000 2,000 1,000 8,000 7,500 7,000 S6.500 .6,000 $ 5,500 3,000 2.500 2,000 1,500 1,000 500 — 1,600 1,500- 1,400 1,300 B g. 1,200 a> o o. ^ 1,000 "f 600- o _l 500 400 300 200 100 ~ I I I I I I SEASONAL YIELDS ***"* Lamb 2nd CUTTING YIELDS m/ / /Dry Matter / /Lamb 1% 62% 11% 46% Pre-bud Bud Bud Bloom Bloom I ! I I ' I I i ! I I i I' ll 96°A Bloom ±1 23 25 27 29 31 2 4 6 8 10 12 14 16 May June Figure 5. Influence of stage of maturity on yield of alfalfa (1955). 18 20 dry matter for the season indicated that either 10 or 50 per cent bloom al- falfa produced the maximum yield; lamb production, however, indicated little difference between 62 per cent bud and the more mature stages. The calculated production of lamb is prob- ably of greatest importance because it is indicative of net nutrient utiliza- tion. Further studies on yield and stand survival were made on a new seeding of Caliverde alfalfa during a four-year trial when harvested at prebud, bud, 10 per cent bloom and 50 per cent bloom. Plots 20 x 30 feet were repli- cated six times for each stage of ma- turity. Each spring the first cutting was taken from all plots at the same time without regard to stage of ma- turity. This removed the winter growth and provided a uniform start- ing date for all plots. Except in 1955 when the first cutting on the new stand was mainly weeds, yield and composi- tion of this material were recorded. Each plot was harvested at the pre- scribed stage of maturity shown in table 14. These treatments were con- tinued for three years (1955, 1956 and 1957), and then, during 1958, all plots were harvested at 10 per cent bloom to [23 test the effect of this differential cut- ting on stand survival. Table 15 shows the average seasonal yield for the three years. To calculate the production of total digestible nu- trient and digestible protein per acre, the digestibility data obtained earlier (table 6) for the various stages of ma- turity were used as the best available estimate. To calculate lamb produc- tion, data from tables 8, 9 and 1 1 were used as the estimated production per unit of feed consumed (weighted daily gain from the analysis of covariance). Illustrated more vividly in figure 6 are the data which confirm those Table 14. Cutting Dates of Alfalfa Harvested at Four Stages of Maturity Yearly cutting number 1955 1. 2. 3. 4. 5. 6. 7. 1956 1. 2. 3. 4. 5. 6. 7. 8. 1957 1. 2. 3. 4. 5. 6. 7. 8. 9 1958 1. 2. 3. 4. 5. 6. Cutting dates at four stages Prebud May 26 June 16 July 8 July 28 August 18 September 9 October 11 April May June June July August September 4 October 9 March April May June June July August September 3 October 3 Bud May 26 June 22 July 18 August 12 September 9 October 11 April May June July August September 4 October 5 March April May June July August September 3 October 7 10 per cent bloom 50 per cent bloom May 26 June 29 July 29 August 30 October 11 May 26 July 6 August 10 September 20 October 11 April 9 April 9 June 1 June 8 June 29 July 13 July 30 August 16 August 29 September 21 October 3 March 25 March 25 May June 6 10 May 13 June 17 July August September October 5 6 6 12 July 15 August 15 September 20 October 17f - All cut at approximately 10 per cent bloom April 16 April 16 April 16 April 16 May 26 May 26 May 26 May 26 June 26 June 26 June 26 June 26 July 25 July 25 July 25 July 25 August 19 August 19 August 19 August 19 October 2 October 2 October 2 October 2 * No bloom. t Early bloom. [24 found in 1955 — more dry matter and TDN production at 10 and 50 per cent bloom. Production of lamb was again highest at the 16 per cent bud stage for two reasons: first, the superior utilization of the TDN after absorp- tion, and second, the greater palata- bility resulting in a greater feed intake and weight gain relative to the mainte- nance requirement. The yield during the fourth season when all alfalfa, previously harvested at four different maturity stages, was cut at 10 per cent bloom is shown in table 16. Although the data appear to show a slight trend towards the plots cut previously at the more mature stages, analysis of variance showed the differences to be nonsignificant; that is, despite three seasons of differential cutting, the alfalfa produced equal amounts of hay during the fourth sea- son when all plots were cut at the same time. Stand counts made during the four years of this study showed no difference in plant density due to cut- ting treatment. The reduced yield of the more frequently cut plots resulted from fewer culms per plant and slower recovery after cutting. Although the results reported here are most applicable to irrigated alfalfa produced in an area with a long grow- 16% Bud 10% Bloom 50% Bloom Figure 6. Average production of alfalfa har- vested at four stages of maturity for a three- year period. Table 15. Yield of Total Digestible Nutrients, Digestible Protein and Lamb from Alfalfa Cut at Four Stages of Maturity Measurements Prebud Bud 10 per cent bloom 50 per cent bloom Alfalfa composition Average seasonal yield, pounds per acre* TDN per pound, per cent TDN yield, pounds per acre Average crude protein yield, pounds per acre Protein digestion coefficient, per cent Digestible protein, pounds per acre 11,829 14,660 17,063 .661 .604 f .572 7,819 8,855 9,760 3,160 3,487 3,521 78.8 74.6f 72.8 2,490 2,601 2,563 17,177 .547 9,396 3,258 70.3 2.290 Lamb response Lamb gain per pound feed, pound J Lamb, pounds per acre 0.103 1,757 0.093 1,597 * Without the first cutting, 1956 and 1957. t Average of values for 1 per cent bud and 62 per cent bud. t Calculated as a weighted average of adjusted lamb gains (tables 8, 9 and 11) from a weighted feed intake of 3.21 pounds per day. [25] Table 16. Yield of Alfalfa During Fourth Season (1958) When Cut at 10 per cent Bloom After Being Cut at Four Stages of Maturity the Three Previous Seasons Previous Number of cuttings Seasonal yield, Protein yield, cutting stage pounds per acre pounds per acre Prebud 6 17,380 3,884 Bud 6 17,860 3,993 10 per cent bloom 6 18,237 3,978 50 per cent bloom 6 18,361 4,015 N.S. N.S. ing season, they demonstrate further the desirability of harvesting forage before it is fully mature. In the more mature alfalfa decreased digestibility, lower utilization, and greater feed re- fusals offset the increased dry matter obtained. At the other extreme, forage cut at too immature a stage, while highly digestible, will not continue to yield enough total forage to make the production of this product practical. The increased number of haying oper- ations per season, coupled with the greater difficulty in drying the imma- ture forage, further increase the cost and labor involved with the short cut- ting interval. The hay producer who is interested only in total hay yield will usually cut at the more mature stages — 50 per cent bloom or later — because he knows from experience that his total yield is high and the hay is easily cured. To produce the maxi- mum feed value as indicated by TDN and digestible protein per acre, the hay should be cut in the late bud to early bloom stages. If hay purchasers buy on the basis of protein analyses or pref- erably lignin or crude fiber content as suggested earlier, hay producers will become more conscious of producing a quality product by harvesting at ear- lier stages of maturity. For hay production where the hay can be cut at a definite stage of ma- turity, the studies reported here show that alfalfa cut when 10 per cent of the stems have one or more flowers in bloom will produce the largest ton- nage of TDN and a good yield of lamb without seriously affecting the vigor of the stand. Woodman and Evans (1935) have reported the starch equiva- lent content and yield of alfalfa. By calculation, their data show a yield of starch equivalent of 2,210 pounds for five cuttings at the prebud stage, 3,282 pounds for three cuttings at the bud stage, and 3,209 pounds for three cut- tings at the early flower stage. Even though as much net produc- tion of usable nutrients from the bud stage is shown by Woodman and Evans (1935) with starch values and, in this bulletin with calculated lamb produc- tion per acre (both measures being in- dicative of net energy production), the bud stage does not seem to be the har- vesting time of choice. Greater inva- sion of weeds, depletion of root re- serves (figure 7) and an increased num- ber of cuttings needed per season rule Figure 7. Alfalfa crown and tap root following various cutting intervals. A — 3-week. B — 4-week. C — 5-week. D — 6-week [26 out this maturity stage. Ten per cent bloom produced yields of lamb as great as those from the bud stages, required fewer cuttings and had adequate root reserves. Further, 10 per cent bloom alfalfa was more digestible and pro- duced greater weight gains than more advanced stages. This stage, therefore, is indicated as the proper time for har- vesting alfalfa. Measuring stage of maturity by crown buds and regrowth in relation to quality While maturity of alfalfa is most commonly described by flowering stage, it is not always possible to use this system. Insect damage, disease and season may mask maturity stages be- cause of damage to buds and flowers or insufficient heat or light to stimulate flowering. Consequently, another method used in conjunction with flowering would provide a more pre- cise determination. The state-wide study on alfalfa characteristics pro- vided information on the use of crown buds and regrowth. Table 17 gives a summary and indicates that occurrence of regrowth and regrowth height are good indicators of three stages — 16 per cent bud, 10 per cent flower and 50 per cent flower stages — in three varieties and one blend (a mixture of several varieties). The good agreement be- tween varieties distributed in all areas of the state (for example, African is grown primarily in the warmer areas) substantiates the use of the method. Sixteen per cent bud alfalfa produced buds on 10 to 45 per cent of the crowns. In 10 per cent bloom, regrowth aver- aged from 0.5 to 0.75 inch on 50 to 75 per cent of the crowns; in the 50 per cent bloom, regrowth averaged from 1.25 to 2 inches on about 80 per cent of the crowns. It appears, therefore, that since crown buds and regrowth are re- lated closely to stage of maturity, qual- ity of alfalfa can be indicated by occur- rence and height of crown buds and re- growth. When growth is interrupted, however, by such things as cold weather in the spring, new growth from the crown buds will appear. As many as three sets of growth, varying greatly in height, may be present at one time in the first cutting. Water stress Table 17. Relation of Bloom Stage to Occurrence of Regrowth Variety Stage Samples Occurrence of regrowth Height of regrowth California common Caliverde Bud, 16 per cent Bloom, 10 per cent Bloom, 50 per cent Bud, 16 per cent Bloom, 10 per cent Bloom, 50 per cent Bud, 16 per cent Bloom, 10 per cent Bloom, 50 per cent Bud, 16 per cent Bloom, 10 per cent Bloom, 50 per cent number 21 19 22 21 24 18 16 16 13 9 16 14 per cent 13 53 81 19 55 78 27 58 77 44 76 85 inches to buds* 0.57 1.24 to buds* Blend 0.73 1.95 to buds* African 0.83 1.80 to buds* 0.69 1.22 * About 40 per cent of the crowns had buds while the remainder had not formed crown buds. [27] o *£ j- o 8 c 8 o 3 O *z s > e c 'a o 1- 0. i- O # c "E 0) 13 ■D C o C *■ iA "o X c o o o CD c o u i. o u ■u c 8 C o (A o V. 8) O O I I 00 (O H o to >o CD 00 00 t£) CD CD <6 <6 <6 d (6 <6 I I I I I I •^ 00 d d I I CO CO CO 00 t> ^ X X CO CO CO 00 X X X X X X OS CO 00 OS « >« >< f* >« >« X X lO C75 O 00 co m d d I I O CD CO CO II II C- "J H CO CO CO ►« PH >H CD C- lO CD S= P= » ■ c^o ten ton t- t> tH CO O t> CD C^ CD lO CO 1*3 d d d d d d ■^ o ■^ CO o c- t- 00 00 t- co CO o o o o o o lO |> Tji CO + + X X CO ^ 00 ^ O i-i d d II II CO O ^ CD CD t* o co co H N 05 CO « O CN CM iH i-H iH t-I d d d d d d Oi 00 ■^" CO + + X X r-i © O *H d d II II II II II II II II tN CD 00 tH CD 00 CN CN CN CN CO + + + + 180X 157X 142X X o o o o II II II II X >< tH {H CD t- CO 00 CD 00 5 >» ^ o 02 Jx •S o o O 1 u I fl ^ S ^ ? I S O fc 3 M M £ 2* w a o • s ■ ■3 ■ OW M ©-s'S.2.2 OT a ^ ** *■ li'll # -t— ++ur-== followed by irrigation will often cause regrowth. This is seen in the hot desert areas. Measuring stage of maturity by height of plant in relation to quality A further search for some physical measure of quality revealed that height of stand, irrrespective of matur- ity stage, year or cutting, was corre- lated with lignin content in the hay harvested at Davis and fed to sheep (tables 8, 9, 10, 11). The regression of height and lignin content at harvesting was highly significant (figure 8). This was also true for height and protein content. Since our results show a very high correlation between lignin con- tent and adjusted daily gains (table 3), height appears to be a good indica- tion of the time to harvest alfalfa for the quality desired. Of course, harvest- ing procedures have a further influ- ence that would be indicated not by height of stand but by lignin or crude fiber. A high correlation (r = 0.66 and -0.73, respectively) was found between height and lignin or protein content of alfalfa collected in the state-wide sur- vey (table 18). The regression of lignin or protein on height was not signifi- 38 — i — i — r i i i PROTEIN Y= 35.75 -0.4I88X - 35 - Y : Per cent protein " 32 X : Height of stand - 29 ^^^^ r ■ -0.88 - 26 ^^\ 4«-«* - 23 - ^"^^\L " £ 20 - ^^-1-^^ ^ " cc — 1 — 1 — 1 — 1 — 1 — t- — i — ( — i — l — I — i — - • a! 8.6 LIGNIN ^ " 7.8 ]^^ - 7.0 - ' ^>^^ " 6.2 - - 5.4 - . ^*^ . . Y : 0.I474X +2.30 Y : Per cent lignin " 4.6 - ^^"^ X - Height of stand - 3.8 i i i l i I r > 0.95 1 I 1 1 1 ! 1 1 ~ 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 HEIGHT OF STAND (INCHES) Figure 8. Relation of preharvest lignin and protein content to height of alfalfa stand. cantly different among the various areas and counties, and therefore one regression can be used. The regression of an increase of 0.14 percentage unit lignin for every height increase of 1 inch or a decrease of 0.47 percentage unit protein for each height increase of 1 inch appears to be the best estimate for the state as a whole. This does not mean that 0.14 will always apply to individual areas but should be used until greater numbers of observations in an area confirm or deny this figure. Table 19. Suggested Prediction Equations to Estimate Lignin and Protein from Height of Alfalfa Stand County* Regression equations! Lignin Protein Shasta Y = 0.14X + 3.2 Y = 0.14X + 2.8 Y = 0.14X + 3.6 Y = 0.14X + 3.3 Y = 0.14X + 3.8 Y = 0.14X + 3.0 Y = 0.14X + 3.5 Y = 0.14X + 3.3 Y = 0.14X + 3.0 Y = 32.2 - 0.47X Yolo Y = 35.7 - 0.47X Stanislaus Monterey Y = 33.9 - 0.47X Y = 34.9 - 0.47X Fresno Kings Y = 35.4 - 0.47X Y = 34.8 - 0.47X Kern Y = 35.2 - 0.47X Los Angeles Imperial Y = 34.1 - 0.47X Y = 33.6 - 0.47X * Soil types within a county were combined because soil type had no significant effect on these relationships. t Y = estimated lignin or protein content while X equals height of stand. [29] Attempts to improve the accuracy by removing from the variance terms the effects of stage of maturity, area or variety, did not increase the accuracy of the predictions. Three other studies on the University farm at Davis not included in the above data showed highly significant correlations (rang- ing between 0.80 to 0.95) between height and lignin or protein content. Valid estimates of quality as indicated by lignin or protein, therefore, can be made with some degree of confidence from the height of the plant irrespec- tive of year, stage of maturity, cutting or variety. Highly significant differences in the elevation of the slope of the regression line between counties were found. Nevertheless, the same regression should be used, although a slightly dif- ferent equation should be used in each of the areas studied until more infor- mation is obtained. Table 19 gives the suggested equations to estimate pre- harvest lignin or protein content from height of stand. How to determine 10 per cent bloom alfalfa Since 10 per cent bloom is, from most standpoints, the desirable time to harvest alfalfa, table 20 gives a sum- mary of the methods for determining 10 per cent bloom in all areas in the state. Counting the number of culms in blossom (figure 1) is one method, but occasionally insect and disease damage or weather interferes with blossoming. Crown regrowth can then be used as a guide. When 60 per cent of the crowns show regrowth of about Table 20. How to Determine 10 per cent Bloom Alfalfa FROM BLOSSOMS: Cross the field, selecting at random between the levies a few major culms at a time, and then count the number of culms with one or more blossoms. Ten per cent bloom means that 10 per cent of the stems selected at random had one or more blossoms. FROM CROWN BUDS AND REGROWTH: Ten per cent bloom is also indicated when 60 per cent of the crowns have buds or re- growth which averages 0.75 inch. FROM HEIGHT OF PLANT, LIGNIN AND CRUDE FIBER CONTENT: County Height* Ligninf Modified crude fiberf Shasta Yolo Stanislaus, sandy soil. Stanislaus, heavy soilt Monterey Fresno Kings Kern Los Angeles§ Imperial, sandy soil. . . Imperial, medium soil. Imperial, heavy soil. . . inches 26.4 28.6 19.2 25.0 21.0 21.0 19.0 24.0 23.0 18.6 16.4 17.1 per cent 6.9 6.8 6.4 6.9 6.3 6.8 5.6 6.9 6.5 5.6 5.3 5.3 per cent 23.8 23.5 22.3 23.8 21.9 23.5 19.7 22.3 22.6 19.7 18.8 18.8 * Average height measured between levies at random across the field. t Analysis before harvest. t Tracy area. § Antelope Valley. [30] 0.75 inch, it is estimated that the al- falfa has reached 10 per cent bloom. This seems to be true for most varieties and areas of California (table 17). Height of stand can also be used as a guide to maturity. This index varies somewhat from one area to the next. It was possible to calculate the expected height of alfalfa in 10 per cent bloom in various areas from data obtained in the state-wide survey (table 19). Height would be particularly useful in antici- pating the proper time to cut. In some areas it seems to be a good prediction of quality. Note that some stands may not reach the expected height. These are guides to be used in conjunction with other methods. Before harvesting, it might be useful to analyze the al- falfa chemically for lignin or crude fiber (table 20) to estimate stage of ma- turity. This may prove to be the more exact method. It must be kept in mind, however, that the harvesting process will further influence the lignin and crude fiber content of the harvested hay. Harvesting alfalfa on a calendar basis Variability of alfalfa hay is increased when a set number of days between harvesting is used, even though this procedure does simplify the manage- ment of men and machinery. Table 21 illustrates this variability of stage of maturity and protein content. A four- week cutting interval results in protein ranging from 20 to 27 per cent, whereas a five-week interval results in 17 to 22 per cent protein. It is apparent that harvesting alfalfa at a definite stage of maturity rather than on a calendar basis would control this variability. The objective — a consistent, high- quality product — will not be attained unless alfalfa is harvested at a con- sistent stage of maturity (figs. 9, 10). Figure 9. An example of regrowth found in plants from 50 per cent to full bloom. Some re- growth is above and some below mower height. Harvesting at this time results in uneven growth since the regrowth which is not cut off by the mower continues to grow, while regrowth which is cut off by the mower must develop new buds. [31] .s« 5S OS CO t- oo t> i-H iH iH iH iH *l ! a a g u o M (N lH iH tH CN tH 8 fcS. 1 c 09 s s a a a e o o o o o o o o o o ^ £ 43 43 43 43 42 (A o "C3 e bo co p A (^ p fl > 3 > CD 0) CD CD CD i. CO s o o O O O o >■ (-1 fH M fH fH X CD co CD CD CD CD ■2 M A A Pi Pi 13 P c bo Oi CO O CO iH X 5 sr i IO CO CO w CO •2g g s it IS S3 CN CN CN o CN CO CN CN CN 8 hg, c < ,24 s O •*• e e o £ 2 B c a u o En I CO p 43 •♦« CD U u CD +» p CD O fH CD Pi O T5 P 43 o 43 Pi CD O E u "S TJ A 7 CD T3 CD e8 P ^ A c8 S P H n iH CN J pq IP ■u -4a 1 c .S« 1 •g . O) 00 o t> CO 0) t> o 3 2 * 1 CM CN CN CN g 1— Ci CO a fl> 3 c« bfl H- 3 > ■^ r-iod id CN OJ CO (N ojcoeod l> ** i-i 00 tF v-i 00 lO iH 00 lO CN CJ co 2 SI iH CM CM tH iHCN tH CN CO iH CN CN HHtN rH CN CN CD n in CD 42 S CD -** Pi CD 09 fH > c9 13 CD 1 1 CO S3 tr CD 43 O o O § CO ca CD CO Figure 10. An example of an extremely uniform field of alfalfa. Previously this field had been harvested at 10 per cent bloom or earlier. Because recurrent growth from the crown had not been damaged by the mower, the culms attained a uniform height. Only one variety was planted so that the entire field matured at the same time. LOCATION— EFFECT ON QUALITY How geographical location affects al- falfa was the purpose of a study which began in 1952 and ended in 1957 with a comprehensive survey of alfalfa char- acteristics throughout California. Lig- nin content, one of the best indicators of quality, varied with location even at the same stage of maturity (table 5). Alfalfa from Imperial Valley and the old Tulare Lake Bed in Kings County was lowest in lignin followed by that from the Lancaster area of Los Angeles County, while the remaining counties were comparable. Protein content fol- lowed a similar pattern but was not as decisive. Physical characteristics — height of stand and leaf percentage (table 22) — also followed the general classification indicated by lignin. Fur- thermore, the regression equations re- lating height and lignin (table 18) de- pict a similar picture. No significant difference was found between areas or stages of maturity in stem diameter (table 23). (See figs. 11, 12, and 13.) To confirm further effects of geo- graphical location on alfalfa quality, a series of digestion trials was con- ducted with alfalfa harvested in vari- ous counties at the same stage of ma- turity. Here, differences between areas were apparent (table 24). Generally speaking, Imperial Valley, Palo Verde Valley and the Lancaster area of Los Angeles County were comparable in TDN or digestible protein, whereas other areas in the state produced al- falfa lower in TDN and digestible pro- tein. The digestion trials confirm, therefore, the results found with lignin. In summary, considering the various measurements, higher-quality alfalfa was produced in the Imperial and Palo Verde Valleys, while that produced in the old Tulare Lake Bed region of Kings County and the Lancaster area of Los Angeles County was slightly lower in quality. The other areas in the Central Valley, Monterey County [33] Table 22. Influence of Location on Height of Stand and Leaf Percentage County t Height of stand 16 per cent bud 10 per cent bloom 50 per cent bloom Mean Per cent leaf 16 per cent bud 10 per cent bloom 50 per cent bloom Mean inches per cent Shasta, II Yolo, IV Stanislaus, I. . . Stanislaus, IV.. Monterey, II . . . Fresno, II Kings, IV Kern, II Los Angeles, I. Los Angeles, IV Imperial, I Imperial, III . . . Imperial, IV . . . Mean J 21 21 16 20 18 16 14 20 19 16 19 15 16 28 28 20 25 23 23 19 24 21 21 20 17 18 27 33 24 25 25 26 23 30 25 25 23 22 20 26 a 27 a 20 bd 23 bc 22 bc 23 bc 19° 24 bc 22 bc 21 bcd 21bcd 18 d 18 d 49.0 55.6 61.5 58.3 62.2 60.2 64.8 58.3 59.2 60.4 57.8 61.0 61.0 49.5 44.7 49.6 47.2 56.5 52.8 52.7 54.4 54.7 51.2 54.6 50.8 58.4 56.3 54.7 47.0 56.6 57.6 56.6 54.4 57.0 55.6 60.2 56.3 60.0 59.3 55.7 53.3 47.6 a 51.4 ab 56.9 cd 55.2 b 56.3 C 54.7 b 59.4 d 54.0 b 57.7° 57.1 C 56.8 C 59.0 d 60.0 d 18 22 25 21.6 59.4 56.1 * Results of a survey study made in 1957. 1 1 = sandy soil; II = sandy loam; III = medium loam; and IV = clay loam. i Significant difference between maturity stages. a Values with the same letter superscripts are not significantly different, while those with different super- scripts are significantly different (0.05). Table 23. Influence of Location on Stem Diameter* Countyf Stem diameter 16 per cent bud 10 per cent bloom 50 per cent bloom Mean Shasta, II Yolo, IV Stanislaus, I . Stanislaus, IV. . Monterey, II . . . Fresno, II Kings, IV Kern, II Los Angeles, I . , Los Angeles, IV Imperial, I Imperial, III Imperial, IV . . . Mean| 0.081 0.075 0.076 0.083 0.087 0.082 0.080 0.079 0.089 0.093 0.087 0.077 0.071 0.081 inches 0.086 0.094 0.082 0.087 0.097 0.083 0.083 0.079 0.096 0.096 0.091 0.086 0.080 0.087 0.097 0.095 0.089 0.088 0.098 0.090 0.094 0.092 0.096 0.095 0.098 0.093 0.084 0.092 0.088 0.086 0.082 0.086 0.093 0.085 0.086 0.082 0.094 0.094 0.091 0.085 0.078 0.087 * Results of a survey study made in 1957. 1 1 = sandy soil; II = sandy loam; III = medium loam; IV = clay loam. X Significant differences between maturity stages. [34] Figure 11. Left. An example of 10 per cent bloom alfalfa growing in the hot desert area of Imperial Valley. It is very short, but high in total digestible nutrients — 65 per cent on a dry-matter basis. Figure 12. Right. An example of 10 per cent bloom alfalfa growing during a cool season at Lancaster. It is medium height but has a high content of total digestible nutrients— 61 per cent on a dry-matter basis. and the Fall Creek area of Shasta County produced alfalfa hay which was lower in these quality measure- ments. However, it is quite possible that environmental conditions in areas of these latter counties which were not studied could result in high-quality alfalfa. Certainly, stage of maturity Table 24. Influence of Location on Digestibility of Alfalfa Alfalfa measurements by year County Shasta Yolo Mon- terey Tulare Los Angeles River- sidef Im- perial 1952 — 50 per cent bloom Lignin, per cent Protein, per cent TDN, per cent Digestible protein, per cent 1953 — 30 per cent bloom Height, inches Lignin, per cent Protein, per cent TDN, per cent Digestible protein, per cent 1954 — 30 per cent bloom Height, inches Lignin, per cent Protein, per cent TDN, per cent Digestible protein, per cent 10.2 18.3 55.0 b 14.0 C 9.0 15.0 57.0 b 10.6 b 25.0 9.2 19.0 59.0 a 15.4° 31.0 9.3 16.2 52.0 b 11.0 b 30.0 10.2 17.2 52.0 b 12.7 b 26.0 10.6 16.5 51.0 b 11.6 b 28.0 10.0 17.4 52.0 b 12.6 b 20.0 8.3 22.6 57.0 a 17.8 a 7.4 20.9 63.4 a 16.7* 16.0 8.4 20.5 59.0 a 15.2 a 14.0 7.3 18.9 58.0 a 14.4= * All results are on a dry-matter basis. t Palo Verde Valley. a Values with the same letter superscripts are not significantly different, while those with different super- scripts are significantly different (0.05) . [35] can be manipulated to result in equiv- geographical location cannot be ex- alent high-quality hay from all areas plained on the basis of temperature of the state. If alfalfa in the Central differences. Valley counties and Monterey or Shasta Counties was cut at the 16 per cent bud stage, the resultant quality would average as high as that from Im- perial, Palo Verde or Antelope Valleys or from Kings County cut at 10 per cent bloom (table 5). Soil type had a distinct effect on lig- nin content of alfalfa grown in Im- perial County (table 5). Lignin was lowest in alfalfa produced on the heavy, clay loams, intermediate for the medium loams and highest for the sandy soils. Protein followed a similar, less distinct but inverse pattern. In a like manner, height of stand was low- est and percentage leaf was highest for alfalfa produced on the heavier soils (table 22). The study of two soils in Los Angeles County revealed slightly higher quality for alfalfa produced on the clay loam but differences were not significant. Stanislaus County showed no soil differences. No relation could be found between temperature and lignin or protein con- tent. Apparently differences between Figure 13. An example of 10 per cent bloom alfalfa, typical of early alfalfa in the northern counties. The stand contains 58 per cent total digestible nutrients. Table 25. Influence of Season on Alfalfa Quality in California Month January. . . February . . March. . . . April May June July August. . . . September October . . 16 per cent bud 5.4 5.6 4.8 5.7 6.2 5.9 6.1 Lignin content 10 per cent bloom 50 per cent bloom Mean Protein content 16 per cent bud 10 per cent bloom per cent 50 per cent bloom 4.6 4.6 28 4.2 5.2 4.7 32 29 5.8 5.8 5.8 22 22 5.7 6.2 5.7 25 24 23 5.7 6.6 6.0 27 24 22 6.3 6.5 5.8 27 22 22 6.7 7.6 6.7 25 22 20 6.8 7.7 6.9 26 24 21 6.7 7.2 6.6 26 24 21 7.3 7.4 6.9 29 24 26 Mean 28 31 22 24 24 24 22 23 24 26 [36 SEASON— EFFECT ON QUALITY Season of the year had a distinct ef- fect on the quality of alfalfa as indi- cated by lignin and protein content (table 25). Three distinct and definite periods were found for quality of al- falfa grown in the Imperial Valley. In January and February alfalfa was low- est in lignin and highest in protein, although at that time of the year it was difficult to harvest and cure prop- erly. March through June was the second period, when the lignin content aver- aged 5.8 per cent and the estimated preharvest TDN was 64 per cent. Pro- tein content averaged 24 per cent. The third period, when alfalfa qual- ity was lowest, was July to October. Lignin rose to 6.8 per cent and the esti- mated preharvest TDN was 61 per cent — a drop of three percentage units from the March-to-june estimate. Pro- tein content did not show such a marked difference. Generally, for California as a whole, there are two important periods for alfalfa hay quality. From March through June hay appears to be high- est in quality, whereas from July to October it is lower in quality. Harvest- ing hay at more immature stages would nullify these differences and result in higher, more consistent quality hay throughout the season. A further study (table 26) was done on the Davis campus using growing lambs to evaluate alfalfa harvested in April, July and August in 10 per cent Table 26. Influence of Season on Quality of Alfalfa as Measured by Response of Growing Lambs* Measurements Date harvestedf 4/29/58 7/31/58 8/28/58 Alfalfa composition Lignin content, per cent Protein content, per cent Lamb response Number of lambs Average initial weight, pounds Average daily gain, pounds Daily feed intake, pounds Adjusted daily gain, pounds Gain per 100 pounds feed consumed, pounds Carcass data Dressing, per cent Carcass grade: Choice, number Good, number Utility, number 7.2 21.9 12 12 65.0 65.0 0.30 0.31 3.02 3.03 0.29 0.29 9.75 10.1 12 63.0 0.28 2.75 0.31 10.2 48.3 47.7 1 9 8 3 3 48.3 2 4 6 * Sixty-day feeding period. t AH three cuttings harvested at 10 per cent bloom from the same blocks in a field of Caliverde alfalfa on the Davis Campus. [37] bloom. No significant effect of season was found with any of the measure- ment criteria used with the lambs. Neither growth nor feed consumption was affected by alfalfa harvested at the different periods. Why this latter study with lambs did not confirm the state- wide study of seasonal effects on alfalfa quality (table 25) cannot be ascer- tained at this time. The study with lambs was by no means as extensive and may have been a chance occur- rence. Nevertheless, it is concluded that the three main seasons — January to Feb- ruary, March through June, and July through October — for California as a whole have real influences on alfalfa quality. Generally livestockmen prefer first and last cutting hay. These data support in a general way the prefer- ence for first cutting hay but not for last cutting hay. The last cutting hay in many areas is harvested at a more immature stage, while in this research the October hay was allowed to reach the desired maturity stages. VARIETY— EFFECT ON QUALITY Quality of hay does not seem to be affected by differences in variety. In the studies reported here, chemical composition, lignin and protein did not vary between Caliverde, California common or a blend (table 27). Even though African alfalfa was lower in lignin and higher in protein, it was concluded that this difference was en- tirely due to geographical location, since all the African alfalfa was grown in Imperial Valley which was shown to produce higher quality alfalfa. The physical characteristics — height of stand and leaf percentage — which in- dicate quality also show the same re- sults. A further study was made on the comparison of African and California common, both grown in Imperial Val- ley (table 28). A digestion trial was in- cluded to make the study more com- plete. Here, no apparent difference existed between varieties as measured with lignin and TDN. Slight but non- Table 27. Composition and Characteristics of Alfalfa Varieties Number of samples Lignin content Protein content Variety 16 per cent bud 10 per cent bloom 50 per cent bloom Mean 16 per cent bud 10 per cent bloom 50 per cent bloom Mean 63 62 45 39 63 62 45 39 per cent Caliverde 5.8 5.6 5.7 5.3 6.4 6.7 6.4 5.2 7.0 7.1 7.2 6.3 6.3 6.5 6.4 5.6 26.4 26.8 25.9 25.1 23.4 22.7 23.4 26.4 21.3 21.3 22.2 22.6 24.8 California common 23.6 Blend 23.9 African 24.7 Height of stand Percentage leaf inches per cent Caliverde 18.8 17.8 17.3 16.8 23.0 23.2 22.8 16.6 27.8 25.4 24.8 21.7 22.9 22.1 21.4 18.4 59 60 60 60 55 54 56 60 52 53 53 57 55.4 California common 55 8 Blend 56.3 African 58.6 38 significant differences were found in digestible protein content. A more complete study was con- ducted on the Davis campus (table 29). Most measurements, leaf percentage, protein content, digestible protein con- tent and TDN, showed Caliverde to be superior to African, California com- mon and Lahonton varieties. Cali- verde, however, was more immature as indicated by bloom or height of stand. This was probably the reason for its superiority and therefore was not a real varietal difference. Considering all the data given above, it seems unlikely that differences in quality will be found between these major varieties used in California. Table 28. Digestibility and Composition of Alfalfa Varieties Measurements African California common Bloom stage, per cent flower Height of stand, inches . . . Lignin, per cent Protein, per cent Digestion trial : Number of trials Digestible protein, per cent Total digestible nutri- ents, per cent 50 19.5 8.2 19.0 4 14.6 59 50 16.0 8.4 20.5 4 15.2 59 * Alfalfa was grown at the Imperial Valley Field Station. All results are on a dry-matter basis. Table 29. Digestibility and Composition of Alfalfa Varieties Measurements African California common Lahonton Caliverde Bloom stage, per cent flower Height of stand, inches Percentage leaf Lignin, per cent Protein, per cent Digestion trial: Number of trials Digestible protein, per cent Total digestible nutrients, per cent 16.0 27.4 51.0 6.7 20.1 5 15.7 58.0 10.0 25.1 51.0 6.1 21.4 5 17.1 59.0 9.0 27.3 51.0 7.2 18.9 5 14.8 58.0 6.5 22.5 51.0 6.3 20.6 5 16.3 61.0f * Alfalfa was grown on the Davis Campus. All results on a dry-matter basis. t Difference was statistically significant (0.05). ALFALFA APHID DAMAGE Insect damage to alfalfa not only lowers production but influences qual- ity of alfalfa. In this survey when lig- nin content increased, aphid damage generally became more severe (table 30). These data did not produce sta- tistically significant differences but possibly trends were indicated. None of the alfalfa used in the survey study could be considered severely damaged by aphids. Again, as has been found in other studies, protein content was not as affected by aphid damage as was lignin content. FORAGE TYPE— EFFECT ON QUALITY The choice of how forage is to be fed to animals is important for maxi- mum economical production. Pastur- ing, since the beginning of agriculture, has predominated. Haying was devel- oped principally to offset winter for- age shortage, even though much of the alfalfa hay in California is now fed during the growing season. Soiling (harvesting and feeding green forage) 39 Table 30. Alfalfa Aphid Damage Test conditions Lignin content 16 per cent bud 10 per cent bloom 50 per cent bloom Protein content 16 per cent bud 10 per cent bloom 50 per cent bloom per cent 1. No aphids present 2. Aphids present, no damage 3. Aphids present, light honeydew, 1-3 lower leaves were yellow . . 4. Aphids present, heavy honeydew, black fungus 5.7 6.1 5.6 6.6 6.2 7.7 7.6 7.1 7.1 6.8 8.0 26.4 26.6 27.8 22.9 26.0 23.6 23.0 21.2 22.3 22.6 20.5 Does not include Shasta and Imperial Counties where no aphid damage was present. at first proved useful where labor was inexpensive and land was intensively farmed. The practice then waned, but development of labor-saving machines, the forage harvester and self-unloading wagon revived the practice of soiling in the United States. Intensive irrigated farming in Cali- fornia on expensive high-producing land requires maximum forage utiliza- tion if forage is to survive competition with other cash crops. Moreover, for- ages such as alfalfa are important as an integral part of the crop rotation. The California Experiment Station, therefore, embarked on studies to em- phasize and develop principles of for- age utilization. In the experiments summarized be- low, ordinarily 10 steers were used per treatment, weights were taken after a 12-hour stand without feed or water, and the chromogen-chromium tech- nique was used for feed intake and digestibility determinations. The for- ages were produced on irrigated fields and rain was not a factor in producing high-quality hay, maintaining a strict Table 31 . Effect of Forage Type on Beef Production per Acre of Alfalfa Year Days Rotational grazing 10-day 6-day 1-day Strip* grazing Soiling Fresh Wilted Haying pounds per acre 1952 1953 1954 1956 1952 1953 1954 1956 (168) (155) (132) (108) 417 580 704 568 525 539 678 689 739 1,080 447 563 per cent of production from soiling 59 77 64 80 82 79 68 100 100 100 100 81 576 856 85 79 * A strip 670 X 3 feet daily for 10 steers. [40] Table 32. Effect of Forage Type on Beef Production per Acre of Alfalfa — Daily Gains and Feed Utilization Measurements 6-day rotational grazing Strip grazing Soiling Haying 1954 Daily gains, pounds Feed consumption, pounds Gain per 100 pounds of feed, pounds Daily gains, pounds Feed consumption, pounds Gain per 100 pounds feed, pounds . . . 1.62 1.42 1.40 1.13 13.9 12.8 15.0 19.0 11.7 10.0 9.3 5.9 1956 1.65 19.2 8.6 1.34 23.0 5.8 pasture rotation or inhibiting the soil- ing operation. Forage production was always adequate and at no time were the animals short of feed. Details of the experimental procedures are de- scribed in the references. Beef production per acre Of the various methods studied, soil- ing produced the greatest quantity of beef from one acre (table 31). Since maximum production was achieved by soiling and it caused the least forage loss, it was used as the standard for comparison. Rotational grazing pro- duced only 59 to 82 per cent as much beef as soiling. Decreasing the grazing interval increased production per acre. However, it did not appear practical to reduce the grazing interval to less than 6 days. Even an intensive strip- grazing method, using a strip of forage 670 x 3 feet given daily, did not ap- proach the productivity of soiling and was little better than a 6-day rotational grazing interval. Haying, while pro- ducing more beef than pasturing, pro- duced only 79 to 85 per cent that of soiling. Even wilting alfalfa to 40 per cent moisture before feeding produced less beef than soiling. Here, also, leaves and fine stems were lost. Soiling the forage prevented not only the animal- induced loss in pasturing but also the machine-induced loss in haying. Un- less there are other considerations, therefore, soiling is the most produc- tive method of processing forage. Animal response The forage method has an influence on animal response (table 32). In the 1954 experiment, grazing and soiling produced comparable gains but the animals fed soilage consumed more feed and produced less gain per unit of feed consumed. Haying in 1954 and soiling in 1956 produced lower gains than grazing did, even though the steers consumed more feed. Efficiency of forage utilization was lowest for the steers fed hay. It must be remembered, however, that greater quantities of beef per acre were produced from soil- ing followed by haying even when gains were lower. The higher feeding value of soilage compared to hay is further illustrated by the greater quantities of concen- trates needed to fatten steers when hay was fed (table 33). In this experiment lower gains resulted from hay feeding than from soilage feeding, but when soilage and hay were supplemented [41] Table 33. Effect of Forage Type on Supplement Needs of Steers (1957) Daily gain Feed intake Forage type Rough- age Concen- trate Unsupplemented pounds Soilage 1.96 1.60 17.7 18.2 Hay Supplemented pounds Soilage 2.21 2.16 12.5 11.5 5.5 Hay 7.7 with concentrates gains were almost equal because greater concentrate con- sumption overcame the poorer quality of the alfalfa hay. It appears that pasturing allows steers to consume a higher-quality for- age. Soilage has a lower quality be- cause the steers are forced to consume more of the coarser parts of the plant. Hay, however, is of still lower quality than soilage because of further leaf and fine stem loss. When hay was fed, greater quantities of concentrate were consumed by steers to overcome lower quality of forage. Selective grazing It was pointed out above that cattle given alfalfa pasture made more effi- cient gains than when they were fed soilage. Further experiments (table 34) to study selective grazing included al- falfa and trefoil-orchardgrass grazed by steers and sheep. Sheep were included because they fatten more rapidly on pasture and would illustrate selective grazing more vividly. When either al- falfa or trefoil-orchardgrass forage was fed as soilage, there was no difference in the TDN content of the forage con- sumed by either sheep or cattle. Here there was little opportunity for selec- tion. The TDN content of the trefoil- orchard pasture consumed by sheep and cattle was the same. However, the sheep did select from alfalfa pasture a diet which had a higher TDN content than that selected by steers. The inter- action of animal species and method of feeding was statistically significant. The TDN content of forage consumed by cattle did illustrate some selective grazing on alfalfa, although it did not indicate selective grazing on the trefoil- orchard pasture. Even if cattle select a more highly nutritious forage from pasture, soilage results in greater production because more of the available dry matter is consumed (table 35). Only 52 to 59 per cent of the available forage on alfalfa pasture was consumed, compared to 90 to 97 per cent consumed from soilage. Trefoil-orchardgrass was a more nutri- tious forage (table 34) and a greater proportion (82 per cent) was consumed by pasturing. Selective grazing, which resulted in refusal to eat coarse alfalfa stems to- gether with the higher TDN of the trefoil-orchardgrass, narrowed the im- Table 34. Total Digestible Nutrient Content of Forage Dry Matter Consumed (1956) Forage type Feed Animals Alfalfa Trefoil- orchard- grass Steers Soilage Pasture per cent 56.5 60.7 per cent 66.0 66.4 Sheep Soilage Pasture 58.0 66.1 64.5 67.4 [42 Table 35. Effect of Forage Type on Steer Utilization From One Acre of Feed Forage type 1954 Alfalfa soilage Alfalfa pasture 1956 Alfalfa soilage Alfalfa pasture 1956 Trefoil-orchard soilage. Trefoil-orchard pasture Dry matter available pounds 7,659 7,198 2,688 2,711 1,562 1,567 Dry matter consumed pounds 6,893 3,743 2,460 1,612 1,517 1,389 Amount consumed per cent 90 52 92 59 97 82 Gain per 100 pounds forage pounds 9.3 11.9 5.8 8.6 8.4 7.7 portance of differences in yield be- tween alfalfa and trefoil-orchardgrass. Table 36 shows that trefoil-orchard- grass produced 58 to 63 per cent of the dry matter produced by alfalfa. The steers, however, produced 80 per cent as much meat from an acre of trefoil- orchardgrass as they did from alfalfa, even though alfalfa produced a greater yield of dry matter. An even greater utilization was made by sheep. Yield of forage dry matter, therefore, is not a good gauge of animal production. The desire and ability of steers to do more selection on pasture influenced their eating time (table 37). Steers took more time to eat forage in the pasture than forage fed as soilage. Apparently this was necessary in order to obtain a forage of higher quality. No differ- ence in eating time was noted between the second and fifth day when steers were fed alfalfa soilage; however, con- siderably more time was spent grazing on the fifth day when alfalfa was pas- tured. This difference was not notice- Table 36. Relative Production From Trefoil-Orchardgrass and Alfalfa Soilage (1956) Forage type Yield per acre alfalfa Yield per acre trefoil- orchardgrass Trefoil- orchardgrass production — per cent of alfalfa Forage dry matter yield Soilage Steer pasture . Sheep pasture pounds 5,029 5,268 5,024 per cent 58 63 61 Meat production Steer : Soilage pounds 563 447 463 440 pounds 444 359 417 388 per cent 79 Pasture 80 Sheep : Soilage 90 Pasture 88 [43] Table 37. Effect of Forage Type on Length of Eating and Ruminating Time in Steers Forage type Eating time 2nd day 5th day Ruminating time 2nd day 5th day Alfalfa: Soilage Pasture Trefoil-orchardgrass Soilage Pasture 5.1 6.1 4.0 6.7 hours 4.8 7.5 7.9 4.4 4.4 6.1 6.4 5.9 7.5 7.7 6.9 7.7 able for the animals given trefoil- orchardgrass. Pasturing alfalfa, which allowed selective grazing, resulted in the con- sumption of a more nutritious forage than soiling or haying did. The animals fed soilage or hay attempted to overcome the lower nutritive value by consuming more dry matter per day. This sometimes allowed the soil- age animals to equal the gains of the pastured animals. Even though forage consumed from soiling was of lower value, the greatest production per acre was realized by soiling because the animals did not damage or refuse forage as did the pastured cattle. The mechanics of processing hay resulted in a product lower in quality than soilage and pas- ture. However hay was intermediate in production per acre — less than soil- age but greater than pasture. One-day rotational or strip grazing did not show a practical advantage when com- pared to 6- or 7-day rotational grazing. Selective grazing was more apparent on a tall, sparse-growing plant (alfalfa) than on a low, dense forage (trefoil- orchardgrass). Dry matter yields did not correctly appraise the relative value of various forages. Differences in nutritive value of plants and the in- fluence of selective grazing could only be gauged when animals were utilized for testing. HARVESTING AND PROCESSING METHODS- EFFECT ON QUALITY The experiments reported in this section were designed to study ways of harvesting and processing alfalfa in order to produce the highest quality livestock feed. In addition, feeding methods were studied since they in- fluence animal response and produc- tion per acre, although they may or may not enhance the feeding value of alfalfa. Dehydrating versus field curing of alfalfa hay Since dehydrated alfalfa is taken directly from the field to the de- hydrator with little or no loss of ma- terial, it was expected that dehydrating would result in a higher quality hay than field curing. The two processes were directly compared on alfalfa [44 harvested from the same field at the same time. Any differences in feeding value were undoubtedly due to the various losses incurred in mowing, raking, baling and transporting the field-cured hay. In the field-curing process, the al- falfa was mowed, windrowed the same day (moisture content about 65 per cent), sun-cured and baled at 20 per cent moisture. Neither rain nor insect damage occurred. In the dehydrating process, the alfalfa was field chopped directly and then immediately de- hydrated in a commercial drum-type drier. The field-cured and dehydrated hays were fed as either chopped or pelleted hay. The sheep were handled as described in previously discussed experiments. In 1956 (table 38) a factorial design utilized four maturity stages of alfalfa fed as dehydrated and sun-cured hay. Two methods of feeding were super- imposed and each hay was fed in the pelleted and chopped form. In 1958, alfalfa of two maturity stages from two cuttings (May and August) was fed as dehydrated and field-cured hay. No interactions were present and conse- quently the data were combined for ease of presentation. Table 38. Comparison of Dehydrated and Field-Cured Alf alf c 1* 1956 1958 Measurements Dehy- drated Field- cured Dehy- drated Field- cured Alfalfa composition As harvested : Lignin, per cent. . Protein, per cent . * As fed: Lignin, per cent. Protein, per cent . Sheep response Number of lambs Initial weight, pounds Daily gain, pounds Daily feed consumed, pounds Adjusted daily gain, pounds f Gain per 100 pounds feed, pounds 40 40 24 60.0 60.0 75.0 0.36 0.24 0.41 3.51 2.92 3.44 0.33 0.28 0.41 10.2 8.0 11.8 24 76.0 0.37 3.53 0.37 10.6 Carcass data Dressing, per cent. . . Carcass fat, per cent. Grade : Number of choice . Number of good . . . 50.1 49.4 23.8 24.2 14 9 10 15 * Highly significant differences (0.01) between dehydrated and sun-cured alfalfa. t Adjusted to equal feed intake of 3.22 and 3.48 pounds, respectively for 1956 and 1958. This is a more exact measure of efficiency of feed utilization. [45] Lignin was lower in the dehydrated hay than in the field-cured hay, indi- cating that field curing induced a loss of lower-lignified material during field curing and harvesting. Protein content confirmed the lignin results in an in- verse manner. Here, however, the dif- ferences were not as striking. Dehydrated hay produced gains that were greater than the gains of sheep fed field-cured hay to a highly significant degree. This was indicated not only in the analysis of variance but also in the analysis of covariance, indicating that increased feed consumption would not completely explain the differences. Most of the increased value of de- hydrated hay compared to sun-cured hay was caused by increased nutritive content rather than by increased palat- ability. This was shown from two standpoints in this experiment: first, the lignin content was lower in the dehydrated hay, and second, an ad- justment of weight gains to equal feed consumption by statistical means (analysis of covariance) still showed differences between dehydrated and field-cured hay. Moreover, in other experiments, swine responded to de- hydrated hay as an energy source. Daily gains were 1.26 and 1.17 pounds respectively from 5.25 pounds of a feed containing an average of 22 per cent of either dehydrated or field-cured hay. This indicates that some of the in- Table 39. Comparison of Dehydrated, Field-Cured, and Rain-Damaged Alfalfa (1958) * 0.63 inch. t Adjusted to equal feed consumption. Measurements Dehydrated Field-cured Rain damage* Alfalfa composition As harvested: Lignin, per cent 5.5 27.0 6.9 25.0 5.5 26.0 7.2 24.0 5.5 Protein, per cent 27.0 As fed: Lignin, per cent 7.9 Protein, per cent 26.0 Lamb response Number of lambs 6 74.0 0.44 3.42 0.45 13.0 6 76.0 0.41 3.37 0.44 12.1 6 Initial weight, pounds 73.0 Daily gain, pounds 0.35 Daily feed consumed, pounds 3.31 Adjusted daily gain, pounds f 0.38 Gain per 100 pounds feed, pounds. . . . 10.7 Carcass data Dressing, per cent 51.0 23.0 6 51.0 24.0 3 3 49.1 Carcass fat, per cent 23.4 Grade : Number of choice . . 2 Number of good . . . 4 [46] creased value was in readily digested nutrients, since swine do not respond to lignification as do ruminants. The value of dehydration would be further increased if it also prevented rain damage. During the course of these studies, 0.63 inch of rain fell on i 17 per cent bud alfalfa sun cured in May, 1958. Consequently, a nearby field at the 13 per cent bud stage was harvested and sun cured three days later, and then used as a substitute. Nevertheless, the rain-damaged hay was included in the studies because of the rare opportunity to compare the feeding value of essentially the same hay with and without rain damage. Table 39 reports these results. Lignin increased in the rain-damaged hay indicating a loss of soluble nutri- i ents and a consequent decrease in feed value. Protein did not change with rain damage, possibly because part of the nitrogen fraction is soluble and part is not. This would indicate that protein content may not always be a good indicator of hay quality when leached by rain. The lambs responded with de- creased weight gains and feed con- sumption to field-cured hay compared to dehydrated hay, and a further de- creased response was evident when the hay was rain damaged. Quality of the rain-damaged hay was surprisingly high as indicated by the weight gains and the estimated 52 per cent TDN (90 per cent dry matter). This may indicate either that more than 0.63 inch of rain is necessary to damage hay severely, or that the high quality of the original hay in these studies (17 per cent bud stage) resisted severe damage. Effect of conditioning on alfalfa hay quality Tests at a number of agricultural experiment stations have demon- strated that hay crushed or crimped immediately after mowing dries con- siderably faster than untreated hay. The Department of Agricultural Engi- neering at Davis has found that drying times were usually two days less when either crimpers or smooth-roll crushers were used than when the hay was not conditioned. Field losses due to both mowing and conditioning in 1958 ex- ceeded those due to mowing only. On the average, an additional 1.1 per cent of the crop was lost when the hay was processed with smooth-roll crushers at moderate roll pressures and an ad- ditional 3.6 per cent of the crop was lost when crimpers were used. The 1.1 per cent additional loss resulting from rolling is not economically im- portant but the 3.6 per cent additional loss due to crimping does represent an appreciable loss of income. No differ- ence was found, however, between yields from the rolled and control hay in 1959. Three feeding trials (table 40) were conducted to study animal response to hay that had been conditioned. Sheep were used in trials which in- cluded superimposed treatments in balanced factorial designs: In 1958«, three cuttings each were fed as baled and pelleted hay; in 19586, three cut- tings were fed only as pelleted hay; whereas, in 1959, four qualities of hay (harvested correctly, raked when too dry, baled when too dry, and raked and baled when too dry) were each fed as chopped, watered and pelleted hay. No significant interactions or dif- ferential effects of conditioning with any of these kinds of hays were found and the data consequently were com- bined for presentation (table 40). Conditioning, whether by a crimper or smooth roll, did not significantly affect crude fiber or protein content. Neither did conditioning affect yield of dry matter, TDN, crude protein or calculated lamb production per acre. Response from the sheep bore out [47 the results from the chemical analyses. While a significant increase in gain was found with rolled hay in 1958a, subsequent trials showed no significant differences. It was concluded that the 1958a differences, therefore, were due to chance, and consideration of results from all trials indicates that condition- ing hay with either a crimper or a smooth-roll machine has no consistent effect on feeding response with sheep. This was also confirmed by the carcass data. Feed consumption or refusal of hay whether fed as long hay, chopped hay or pelleted hay was not changed by conditioning. The farmer who conditions his hay has the added costs and problems of an extra operation with a special piece of equipment. He also suffers some additional field loss from the con- ditioning operation. To justify the Table 40. Comparison of Conditioned and Unconditioned Hay Measurements 1958a* 1958b t 1959J Control Crimped Rolled Control Crimped Rolled Control Rolled Alfalfa composition Chemical composition : Crude fiber, per cent .... Crude protein, per cent . . TDN, percent Yields, pounds per acre : Dry matter, pounds TDN, pounds Crude protein, pounds Lamb, pounds Number of sheep Initial weight, pounds Daily gain, pounds Daily feed consumed, pounds Adjusted daily gain, pounds Gain per 100 pounds feed, pounds Dressing, per cent Carcass fat, per cent Grade : Number of choice Number of good Number of utility 27.8 21.8 28.4 21.6 27.6 21.8 26.2 21.7 26.9 21.0 27.7 21.6 28.6 21.0 56.6 2,443 1,383 513 159 27.8 20.9 57.1 2,454 1,401 513 157 Sheep response 12 12 12 9 9 9 36 66.0 67.0 65.0 83.0 84.0 84.0 76.0 0.28 0.27 0.34 0.23 0.21 0.14 0.17 3.00 2.90 3.00 2.61 2.55 2.34 2.64 0.28 0.28 0.32 0.21 0.20 0.18 0.17 9.6 9.3 11.2 8.8 8.4 6.1 6.50 36 77.0 0.17 2.70 0.17 6.46 Carcass data 17.6 49.6 47.3 50.7 50.7 52.0 49.8 50.4 20.6 21.9 24.4 21.0 21.0 3 2 2 1 2 4 7 6 8 7 6 8 28 23 5 3 4 1 6 9 * Represents three cuttings each, fed to two sheep as baled and pelleted hay. t Represents three cuttings, each fed to three sheep as pelleted hay. t Represents one cutting harvested in four ways: handled correctly; raked when too dry; baled when too dry ; and raked and baled when too dry. Each was then fed as chopped, wafered or pelleted hay. [48] use of a conditioner, the producer must consider such factors as (a) the possibility of improved feeding re- sponse or a higher price per ton, (b) possible savings of hay that otherwise might be lost or damaged because of bad weather, (c) the possibilities and importance of improved scheduling of other operations in the haymaking sequence, and (d) possible reduction in time or labor required for other operations. As indicated in a preceding section, tests at Davis did not demonstrate that conditioning improved the feeding response of sheep. Unless the buyer gets better response, he cannot afford to pay a premium price for condi- tioned hay. Fast curing is of far less importance in California than in the midwestern and eastern states. Evalua- tion of items (c) and (d) will depend to a large extent on the individual operation. Influence of haymaking procedures on quality and yield of alfalfa It was shown earlier that field curing of hay, even though correctly managed, produced hay lower in quality than dehydrated hay. Though this was true, production of field-cured hay is far more economical when hay is used as an energy and protein source. As a consequence, most alfalfa hay is field cured. Studies were made, therefore, on the influence of haymaking pro- cedures on quality and yield. Raking the hay too dry was most harmful to quality. Baling the hay too dry did not significantly reduce quality when the hay had been correctly raked (70 per cent moisture) but did reduce quality if the hay had been raked when too dry. An experiment (table 41) was conducted in a uniform field of alfalfa divided into four replications with all treatments repeated in each replica- tion. The control consisted of hay harvested by correct procedures, raked in the morning at a moisture content of 40 to 45 per cent and baled at 20 to 22 per cent moisture. Raking the hay in the afternoon when it was too dry (10 to 15 per cent moisture) was the second treatment, and baling in the afternoon when the hay was too dry was the third treatment. A fourth treatment consisted of raking and baling when the hay was too dry. Superimposed on each treatment were conditioning and nonconditioning; also each was fed as chopped, pelleted and wafered hay. Since no significant interaction was found, indicating no differential effect, the data were com- bined for summary. Before harvesting, the field was sub- divided into the four replications with eight treatments per replication (the four main treatments subdivided into baled and wafered hay). The indi- vidual treatments were sampled for preharvest yields and composition, and at harvest the same procedure was followed. Consequently, an analysis of covariance with preharvest yield or composition as the independent vari- able was used as the statistical treat- ment. Crude fiber increased and protein decreased in hay raked too dry (table 41), reflecting a 2- to 4-percentage unit decrease in TDN. Baling too dry re- duced quality as measured by these chemical constituents only when hay had been raked when too dry. The estimated net energy content showed the same differences. More feed was consumed and greater sheep gains resulted from the control hay and the hay raked at the correct moisture content but baled when too dry. When hay that was raked too dry was fed, not only were gains lowered but also carcass quality decreased. Haymaking practices greatly in- fluenced yield (table 42). Raking the hay when too dry resulted in losses of [49 Table 41 . Influence of Various Haymaking Practices on Quality* Measurements Harvested correctly (control) Alfalfa composition J Crude fiber, per cent§ Crude protein, per cent Estimated TDN, per centH Estimated net energy, megacalories per 100 pounds 26.7 22.4 58.3 54.5 28.7 20.4 56.4 52.9 26.8 21.8 58.1 55.4 II 30.6 19.4 54.6 51.1 Sheep response Number of sheep Initial weight, pounds Daily gain, pounds Daily feed consumed, pounds J. . . . Adjusted daily gain, pounds**. . . . Gain per 100 pounds feed, pounds 18 18 18 77 75 78 0.19 0.15 0.19 2.73 2.52 2.71 0.18 0.17 0.19 7.1 6.1 7.2 18 78 0.15 2.68 0.15 5.6 Carcass data Dressing, per cent. . . Carcass fat, per cent. Grade : Number of choice . Number of good.. . Number of utility. . * During the haymaking, the average daily minimum temperature was 53°F ; maximum temperature was 88°F; the usual dew point range was 45 to 60 and the average wind velocity was 3.2 mph. t Statistically significant differences (0.05) from the hay harvested correctly. t Dry-matter intake. § Modified crude fiber. IT Estimated from crude fiber content. || Estimated from energy gain and maintenance requirements and feed intake. ** Adjusted to equal feed consumption in the analysis of covariance. 750 to 900 pounds of dry matter con- taining 27 per cent protein, 65 per cent TDN and 62 megacalories of net energy per 100 pounds. This resulted in losses of approximately 220 pounds of crude protein, 580 pounds of TDN, 510 megacalories of net energy, or 86 pounds of lamb per acre. The nutrient loss averaged about 28 per cent. Greatest saving, therefore, resulted Table 42. Influence of Various Haymaking Practices on Yield Yield per acre Harvested correctly (control) Raked when too dry Baled when too dry Raked and haled when too dry Dry matter, pounds 2,929 656 1,708 224 1,598 2,187 446 1,233 154 1,158 2,785 604 1,618 217 1,542 1,895 368 Crude protein, pounds TDN, pounds 1,034 115 968 Lamb, pounds Net energy, megacalories [50 when hay was raked with the correct moisture content. Baling when the hay was too dry but raked with the right moisture con- tent did not result in such great losses. Losses varied between 3 and 8 per cent. In addition, quality did not greatly change, as indicated by response of the lambs. Substantial losses did occur, however, when the hay had been previously raked too dry. In this instance, there was a loss of 292 pounds of dry matter (in addition to raking losses) containing 17 per cent crude protein, 68 per cent TDN and 65 therms of net energy per 100 pounds. These losses are about 16 per cent — 78 pounds of crude protein, 199 pounds of TDN, 190 megacalories of net energy or 39 pounds of lamb per acre. Baling hay which was too dry but which had previously been raked cor- rectly, caused an average of 5 per cent nutrient loss as measured by animal response. In this case, however, the leaves had been shattered from the stems and might have been easily lost from the bales. This hay was carefully handled before being fed as chopped or pelleted hay, and no losses occurred after removal from the field. If it had been handled in the usual way, greater losses would have resulted. Further- more, if it had been fed as long hay, most of the leaves would have been lost and possibly cattle and sheep would have refused to eat large portions. Both raking and baling the hay in a dry state caused a loss of 1,034 pounds of dry matter, 293 pounds of crude protein, 674 pounds of TDN and 630 therms of net energy. This nutrient loss is 40 per cent and illustrates the drastic effects of mismanagement. In summary, the most severe loss in haymaking occurred when alfalfa hay was raked when too dry (35 per cent loss), whereas bailing too dry caused only a 5 per cent loss. However, if the alfalfa had previously been raked when too dry, and was then baled too dry, the loss increased 16 per cent over the raking losses. Processing alfalfa hay and its influence on feeding value Alfalfa hay can be fed to sheep and cattle in many different forms — long, chopped, pelleted and watered — and a different feeding response can be expected from each form. An example of the visible changes (figure 14) gives some indication of why the feeding response differs in each case. The long hay distinctly shows the leaves and stems, while coarse grinding and par- ticularly fine grinding make it al- most impossible to distinguish leaves and stems. Pellets and wafers differ markedly from long hay. In figure 14, the feed to the left of the long hay had been both finely ground and com- pressed into a less bulky feed. The feed to the right of the long hay had not been finely ground but had been made less bulky. The pellet (finely ground and compressed) contains 45 pounds per cubic foot while the wafer (coarsely ground and compressed) con- tains 24 to 28 pounds per cubic foot. Pelleted hay. Most experiments have shown an increased gain when hay is finely ground (i/g- to ^-inch screen) and pelleted. A summary of results from California (table 43) shows that larger gains were made by sheep fed pelleted alfalfa hay than by those fed chopped, watered or long hay. In all cases increased feed consumption was mainly responsible for the increased gain. This produced an apparent in- creased feed efficiency (gain per 100 pounds of feed) because more feed was utilized for weight gain rather than for maintenance requirement. Response of steers (table 44) to pelleted hay has not been as marked, although a direct comparison was not made between sheep and steers. These [51 Figure 14. A pictorial comparison of hay prepared in different ways. There are three quarters of a pound in each pile. Table 43. Response of Sheep to Alfalfa Processed by Different Methods Measurement Average daily gain : 1956 (40)* 1957 (18) 1959a (6) 1959b (10) 1959c (18) 1960 (24) Feed consumption : 1956 1957 1959a 1959b 1959c 1960 Gain per 100 pounds feed : 1956 1957 1959a 1959b 1959c 1960 Chopped hay 0.23 0.27 0.24 0.30 0.15 2.8 2.6 2.8 3.1 2.5 7.9 10.6 8.6 9.7 6.0 Pellets Wafers pounds 0.38 0.40 0.38 0.39 0.32 0.24 3.7 3.4 3.6 3.7 3.1 3.1 10.2 11.8 10.6 10.6 10.4 7.8 0.30 0.13 2.9 2.4 10.5 5.3 Long hay 0.27 2.8f 9.6f * Number of lambs per lot. nm 1 JJ I ^ a £?i ti ° n ' * 8 ^ 7 p £* l ent L th , e lon S ha y was wasted and refused by the sheep. If this is included, 3.44 pounds of hay was fed, which would decrease the gain per 100 pounds feed to 7.8 pounds. T 52 "I Table 44. Response of Steers to Alfalfa Processed by Different Methods Measurement Average daily gain: 1957 (6)* 1958 (9) 1959 (6) 1960a (8) 1960b (4) Daily feed consumption : 1957 t 19581 1959 1960a 1960b§ Gain per 100 pounds feed : 1957 1958 1959 1960a 1960b Chopped hay 1.80 1.75 2.00 2.12 1.70 17.6 19.3 19.2 27.6 24.2 10.2 9.1 10.4 7.7 7.0 Pellets 1« pounds Wafers 2tt 2.17 2.22 2.00 2.09 2.13 1.86 2.22 2.08 2.00 2.33 2.14 20.5 22.4 19.2 19.9 19.8 24.7 26.85 27.82 26.66 27.2 28.44 10.6 9.9 10.4 10.5 10.8 7.5 8.3 7.5 7.5 8.6 7.5 1.86 17.9 10.4 * Number of steers per lot. t Includes about 1.6 pounds of long oat hay and 1.81 pounds of barley daily. % Includes about 0.52 pound of long oat hay daily. § Includes about 0.75 pound of long oat hay daily. IF Hay ground through a 1/16-inch screen. || Hay ground through a 3/8-inch screen. ** Dense wafer. tt Loose wafer. steers, studied at the Imperial Valley Field Station, however, were fed an extremely high-quality hay and did make large weight gains on chopped hay alone. Again, as with sheep, in- creased feed consumption seemed to be responsible for the increased weight gains and feed efficiency. Greatest re- sponse to pelleting was obtained from a coarser grind (^-inch screen) before pelleting and when long oat hay was fed. In 1959 and 1960, however, parakeratosis 4 of the rumen, which was 4 Ruminal parakeratosis is a noncontagious disease characterized grossly by hardening, en- largement, and clumping of mucosal papillae and microscopically by accumulation of exces- sive layers of keratinized, nucleated, squamous epithelial cells on the papillae. Jensen, R., J. C. Flint, R. H. Udall, A. W. Deem and C. L. Seger. Amer. Jour. Vet. Res., 71:277-82. 1958. [53 much greater when the pelleted hay was fed, may have influenced the re- sults. This disease was not noted in our lambs but has been reported in Colo- rado lambs fed pelleted rations. Little is known about parakeratosis of the rumen, although it appears to be more prevalent in pellet-fed animals. Long hay, fed in addition, greatly lowered the incidence. The incidence was somewhat greater in cattle fed pellets made from finely ground hay (1/16- inch screen) than in those fed pellets made from coarsely ground hay (s/ s - inch screen). The question arises: Why do sheep and cattle eat more hay when it is pelleted? Investigation at the Uni- versity of California (table 45) has shown no difference in the feeding Table 45. Equalized Feeding of Chopped Hay and Pelleted Hay Compared with Ad Libitum Feeding Hay — Response of Sheep After 56 Days Measurements Chopped hay (equalized feeding) Pelleted hay Equalized feeding Ad libitum Number of sheep Initial weight, pounds Average daily gain, pounds Average daily feed intake, pounds* Feed per 100 pounds gain, pounds* Total digestible nutrients, per cent* Digestible energy, megacalories per 100 pounds* Net energy, megacalories per 100 pounds* 6 75.0 0.27 2.48 910.0 59.0 124.00 62.6 6 75.0 0.26 2.54 960.0 60.0 127.00 65.0 6 76.0 0.40 f 3.25f 810.0 * Dry-matter basis. t Highly significant difference. value of chopped and pelleted hays when lambs were fed equal quantities per day. Digestibility and net energy content were not significantly different. In other words, pound for pound, chopped and pelleted finely ground hays were equal in feeding value. The main difference in feeding value, therefore, between pelleted and chopped hay was the increased feed consumption of the pelleted alfalfa. When a greater quantity of hay is con- sumed, a larger percentage is utilized for gain and less for maintenance, in- creasing the efficiency of feed utiliza- tion. Further investigations in England and California have revealed that in- creased feed intake of pelleted hay is due to a faster passage of hay through the digestive tract. In the present work, the basic reason for the faster feed passage was explored. Studies on rumen contents in a Warburg appa- ratus and studies on rate of cellulose digestibility in the rumen indicated that the pelleted hay was digested at a faster rate. Our theory is that the more rapidly the feed is digested, the more rapidly it will pass through the digestive tract and, hence, a greater feed intake results. Further work showed that the fine grind was re- sponsible for this increased rate of digestibility because merely adding water to finely ground alfalfa increased feed intake and gains to almost the level produced by pelleting finely ground alfalfa. This did not occur with coarsely chopped hay. When 50 to 60 per cent concentrate was mixed with alfalfa and then pelleted (table 46), there was little or no increase in feed consumption or gains. In fact, in 1958, feed consump- tion and weight gains decreased when a pelleted, high-concentrate feed was compared to a milled ration. Other experiment stations have reported similar results. Consequently, little value seems to result from pelleting a ration of alfalfa and 50 to 60 per cent concentrate. Thirty per cent concen- trate seems to be the upper limit which will provoke a response. Apparently, from chemical analysis, 21 per cent crude fiber should be the lower limit in a pelleted ration fed to fattening ruminants. Wafers. Alfalfa hay compressed into wafers is much more dense than chopped or long hay but it is not much different in particle size (figure 14). Consequently, if fine particle size is [54] responsible for the faster rate of di- gestion, greater feed intake, and hence greater weight gains of ruminants fed pelleted hay, a marked response should not be expected when hay is wafered. Over-all perusal of the data (tables 43, 44) does not reveal increased feed in- take by sheep or cattle of hay made into wafers compared to chopped hay. In some cases gains were increased but not to a statistically significant extent. Pelleted hay, in most cases, produced a greater feed intake than that pro- duced by wafers. The wafer, while not resulting in a great influence on feed intake, might have an advantage be- cause of easier handling. This study did not measure the physical handling advantages but only the feeding value. The addition of 50 to 60 per cent concentrates to alfalfa before it was compressed into wafers produced an equal or somewhat greater feed intake and weight gain in steers than the addition of 50 to 60 per cent concen- trate to a milled ration. None of the differences were statistically significant. Little or no effect was found in ef- ficiency of feed utilization (gain per 100 pounds feed consumed). Long hay. Figure 14 clearly shows the distinctness of the leaves and stems in long hay. Because of this, sheep were able to select leafy portions from stems and refuse to eat the remainder of the hay (table 43). In this trial, 18.7 per cent of the hay — mainly stems con- taining 42.5 per cent crude fiber — was refused, whereas all the pelleted hay was consumed. Table 46. Response of Steers to Alfalfa Processed by Different Methods and Supplemented with Concentrates* Year Chopped hay Pellets U Wafers H pounds Average daily gain : 1958 (9)f 1959 (6) 1960a (8) 1960b (4) Daily feed consumption : 1958 1959 1960a 1960b Gain per 100 pounds feed : 1958 1959 1960a 1960b 2.46 2.03 2.60 2.63 20.00 15.6 23.35 25.79 12.4 13.0 11.1 10.2 2.14 2.08 2.51 2.20 2.40 2.46 2.78 2.56 2.67 2.82 16.3 18.9 19.8 18.5 22.61 22.35 26.08 24.82 25.73 27.83 13.0 11.0 12.7 11.9 10.6 11.0 10.7 10.3 10.4 10.2 2.66 20.0 13.3 * Consisted of 60 per cent concentrate in 1958 and 1960 ; 50 per cent concentrate in 1959 ; 3 parts ground barley and 1 part molasses dried beet pulp. In 1958, 0.52 pounds of long oat hay was fed, while in 1960b about 1 pound was fed. t Number of steers per lot. t Hay ground through a 1/16-inch screen. § Hay ground through a 3/8-inch screen. If Dense wafer. II Loose wafer. [55 TIME AND LEVEL OF SUPPLEMENTATION- EFFECT ON QUALITY Earlier studies have compared the production of nutrients and of beef or lamb from alfalfa harvested by various methods. Although relatively high gains can be achieved when high- quality alfalfa in the form of soilage or hay is the sole source of feed, an additional source of energy is needed to produce a finished animal with a high dressing percentage and a high grading carcass in a reasonable feeding period. It was shown in an earlier study that barley, fed at the rate of 1 pound per 100 pounds body weight to steers receiving alfalfa soilage, brought about an increased daily gain of approximately 0.5 pound. Molasses alone was shown to be unsatisfatcory as a supplement to alfalfa soilage. Other observations have revealed that a mixture of barley and molasses-dried beet pulp (hereafter referred to merely as beet pulp) is a satisfactory supple- ment to both alfalfa soilage and hay. Steers fed alfalfa alone have con- sistently made good body weight gains, especially during the first half of a 130- to 179-day feeding period, in contrast to steers receiving supple- ments continuously for the entire period. It seemed important to de- termine whether a concentrate supple- ment fed only during the last half of the feeding period produced gains comparable to those produced by supplementing continuously for the entire period. It also seemed important to determine at what level the supple- ment should be fed. Time of supplementation — Experiment 1 Thirty-six head of high-quality yearling Hereford steers weighing approximately 665 pounds were ran- domly assigned to six groups for ex- periment 1 (table 47). The hay fed was harvested at approximately 10 per cent bloom at the Imperial Valley Field Station the summer preceding the study; soilage was also harvested at 10 per cent bloom. Hay or soilage was allowed ad libitum. Barley and beet pulp were fed in a ratio of 3:1, and supplemented lots were allowed all the supplement they would eat twice daily. All lots were allowed a Table 47. Design of Experiment 1 Supplement treatment Roughage None Second 84-day period Continuous for 168 days Number of steers Alfalfa soilage . . . Alfalfa hay . 6 6 6 6* 6 6* * One steer in each of these lots was lost due to causes not associated with the treatments. small amount of oat hay (approxi- mately 1.8 pound daily) to assist in preventing bloat. Statistical analysis revealed no sig- nificant difference in response to the supplements between the animals fed soilage and those fed hay. The daily gains and the roughage consumption on hay or soilage were not significantly different. The supplemented steers on hay, however, consumed an average of 2.2 pounds per head per day more concentrate than those on soilage. Since the gains were not different, the hay, therefore, was of lower nutritive value than soilage. Because the re- sponse to supplement is similar, the data from the lots fed hay have been combined with those from the lots fed soilage and are presented in table 48. Concentrate supplementation dur- ing the second half of the feeding period resulted in a highly significant [56] Table 48. Response of Steers Supplemented for Varying Portions of the Total Feeding Period Supplemental Steers Portion of feeding period Initial weight Daily gain Daily air- dry feed intake Daily TDN intake treatment Rough- age Concen- trate number days pounds None 12 1st 84 days 2nd 84 days 670 829 1.89 1.67 16.7 19.2 8.9 10.2 Entire period (average) 670 1.78 18.0 9.6 Supplemented second 84 days 11 1st 84 days 2nd 84 days 666 836 2.02 2.39 16.2 14.1 7.6 8.6 13.4 Entire period (average) 670 2.21* 15.2* 3.8 11.0* Supplemented for 168 days 11 1st 84 days 2nd 84 days 660 870 2.50 1.86 12.2 11.8 5.7 7.5 10.9 12.1 Entire period (average) 660 2.18* 12.0* 6.6* 11.5* * A statistically highly significant difference was observed compared to the unsupplemented lot. increase in daily TDN consumption of 3.2 pounds per day, although there was a significant drop in roughage consumption. The over-all daily gain was increased by 0.72 pound. Daily gain of the unsupplemented lot dropped 0.22 pound during the second half of the feeding period. However, providing 7.6 pounds of concentrate daily prevented this loss and increased the daily gain 0.37 pound above the gain of the first half. Supplementation throughout the 168-day period resulted in a further decrease in roughage con- sumption with only a slight increase in TDN intake. The daily gain was not increased over the group receiving supplement only during the last half of the period, although approximately 75 per cent more supplement was used over the 168 days. It appears from these data that sup- plementation throughout the feeding period is wasteful of concentrate, since the extra supplement reduced rough- age intake but did not increase weight gain. Inspection of the slaughter data in table 49, however, shows that those steers supplemented throughout the 168 days, although gaining no more, yielded a significantly higher percent- age of dressed carcass and graded con- siderably higher. A higher energy ration, therefore, may produce fatter carcasses without increasing the rate of gain. Further calculations estimate the daily energy gain of 2,644, 4,049 and 5,722 kilocalories for the unsupple- mented lots, for those supplemented the last 84 days, and for those con- tinuously supplemented, respectively. The lot receiving continuous supple- mentation thus gained 40 per cent more energy than the lot supple- mented only the last 84 days, although the gain in body weight was the same for the two lots. [57] Table 49. Slaughtering Data of Steers Supplemented for Varying Portions of the Total Feeding Period Dressing per cent Carcass grades Supplemental treatment Choice Good Standard or commercial 56.7* 58.9* 60.8* per cent None 8 18 64 75 82 36 17 Supplemented second 84 days Supplemented for 168 days * Statistically significant difference (0.05). A consideration of all data prompts the conclusion that, in order to pro- duce a high-grading and high-yielding carcass, continuous supplementation was more satisfactory than no supple- mentation or supplementation only during the last half of the feeding period. Level of supplementation — Experiment 2 Forty-eight high-quality Hereford steers were randomly divided into six lots of eight heads each. Five of the lots were allowed alfalfa soilage ad libitum with various levels of barley and beet pulp supplement. One lot received no supplement, while a sec- ond received all the supplement they would eat twice daily. The remaining three lots being fed soilage received the supplement at the rate of 75, 50 and 25 per cent of the amount con- sumed by the full-fed lot. The sixth lot was allowed alfalfa hay ad libitum plus the supplement full fed. The alfalfa soilage and hay were again harvested from the Imperial Valley Field Station at approximately 10 per cent bloom. Feeding a supplement (table 50) above 3.5 pounds per head per day (50 per cent of full feed) to animals on alfalfa soilage produced no significant increase in weight gain. Increasing the supplement to 5.1 and 6.2 pounds per day (75 to 100 per cent of full feed) brought about an increased TDN con- sumption but no weight gain. It is again interesting to note that the steers full fed supplement on alfalfa hay ate more concentrate than those full fed supplement on alfalfa soilage. The difference in gain was not sta- tistically significant. As in the case of experiment 1, if only body weight gain and TDN con- sumption are considered, erroneous conclusions may be made. From these data alone it appears that there is no advantage to feeding more than 50 per cent of full feed or 3.5 pounds per head per day (approximately 0.5 pound per 100 pounds body weight). Again, how- ever, if yield and grade data are con- sidered, the conclusion is altered. Al- though increasing the supplement above 3.5 pounds did not significantly stimulate daily gains, it brought about a significant increase in the dressing per cent and carcass grade. To summarize, evidence is presented showing that gains made by steers con- tinuously supplemented with concen- trate represented more energy than gains of steers not supplemented or supplemented for only the last half of the experiments. This occurred even though weight gains were the same. Variations in the quantity of concen- trate supplementation produced a sim- ilar result. Weight gains did not in- [58] Table 50. Response of Steers to Supplements Fed at Different Levels with Alfalfa Soilage and Full Fed with Hay Measurements Initial weight, pounds Daily gain, pounds Daily air-dry feed consumed, pounds Roughage * Concentrate Total TDN intake, pounds per day Dressing per cent Carcass grade, number in grade Choice Good Standard or commercial Alfalfa soilage Supplement fed at following percentage of full feed per cent 541.0 2.01 18.3 0.0 18.3 10.1 58.5 7 1 25 per cent 545.0 2.17 17.1 1.8 18.9 10.7 57.7 8 50 per cent 543.0 2.28 14.6 3.5 18.1 10.7 58.3 1 7 75 per cent 542.0 2.34 14.0 5.1 19.1 11.6 59.7 4 4 100 per cent 543.0 2.35 12.5 6.2 18.7 11.6 59.8 3 5 Alfalfa hay Supple- ment full fed 539.0 2.53 11.7 8.5 20.2 12.7 60.4 4 4 crease above a certain amount of sup- plementation but energy gains did in- crease, resulting in higher yield and better carcass grades. Supplementation of alfalfa with high energy concentrates is necessary to produce optimum fattening of beef steers resulting in choice carcasses. CHEMICAL EVALUATION Much of the hay produced in Cali- fornia is not fed on the ranch on which it is produced but is sold, transported and fed at another location. Since both growers and feeders need a gauge of quality, studies were made to develop a method for evaluating alfalfa hay by chemical analyses. It has been shown previously (tables 2 and 3) that TDN and digestible pro- tein can be predicted from a chemical analysis for lignin, crude fiber, modi- fied crude fiber 5 or protein. Even 5 Includes the silica found in alfalfa (see footnote 3, page 8). Silica usually means soil contamination and does not have nutritive value. Since the fibrous portion of the hay has more nutritive value than the nonfibrous portion, inclusion of the silica with the fiber might be a better indication of hay quality than treating it as part of the nonfibrous por- tion, though an analysis of modified crude fiber did not predict digestible protein as accurately as an analysis of protein did, the crude fiber was the constituent of choice for predicting hay quality since it was superior to the other three constituents in predicting TDN. In addition, modified crude fiber analysis is simpler and more rapid and requires less laboratory equipment than analyses of the other three con- stituents. To make the analyses, a simple yet reliable method of obtaining a repre- sentative sample from baled hay was needed. Two samplers (figures 15 and 16) were found to operate satisfac- torily. Figure 15 shows a manually op- erated probe which is pushed 18 inches into the end of a bale of hay. It oper- [59] Figure 15. Manually operated probe. The removable tip is of hardened steel, sharpened, and has a %-inch opening. The inside diameter becomes larger a short distance from the tip so the hay particles will fall easily into the paper carton. The total length of the tube is 24 inches. This probe was developed by G. H. Bath and L. M. Harwood of the California Ex- tension Service, Santa Rosa, California. ates easily in dry hay but less easily in hay with more than 15 per cent mois- ture. The sampler in figure 16 is pow- ered by a l/^-inch electric drill. Ordi- nary wood bits are welded together to provide an 18-inch auger through the tube. Many modifications of the tip of the bit have been tried. The most sat- isfactory method seems to be one where the lips extend forward with a slight set outwards, so that the hole made by the bit is the same size as the tube. This sampler also is difficult to operate in high-moisture hay. Both, 1 Figure 16. A %-inch auger, made of carpenter's bits welded together, draws the hay through the tube and drops the hay into the paper carton. It is powered by a l/2-inch electric drill. [60] Seictiom Scale l /i' • \" 7ie Drill !3 M" Ream Steiel Tip Deltail Scole 2" = I" Uav Saaxpling Probe. University or California Agricultural CHeiisctRiNO, Davis. DpAvri By CaUmdo Checked By JRG ^RO.c Date 5-61 Figure 17. A hand-driven probe which can be used for sampling baled hay for chemical analysis. The hand driver makes it possible to force the probe into a bale even when the hay is relatively "tough." The design and drawing was made under the supervision of R. G. Curley, Agricultural Engineering, Davis. CONSTRUCTION DETAILS Items marked on the drawing are as follows: (1) Seamless steel tubing, %-inch O.D. and .435-inch I.D. (2) Steel collar, 1% inch diameter by Vi inch wide, welded to the tubing and pipe. (3) Vi-inch standard pipe. (4) Movable hammer with relatively snug sliding fit. Suggested weight 4 pounds. Construction detail is shown for the cutting tip made of steel drill rod. A steel or wooden dowel, Va inch by 31/2 feet is recommended for forcing the hay out of the tube and into the pipe after each bale is probed. however, have the advantage of de- livering the hay directly into a carton. For high-moisture hay, a revolving tube with a segment of a band saw blade mounted on the end (with the teeth set slightly inward) and powered by an electric drill seems to be the most satisfactory. Several methods of sampling baled hay were tested and compared. A study of the means and standard deviations in table 51 reveals that all of the vari- ious methods seem to sample a bale of hay within reasonable limits. Ap- parently as long as a complete core sample is taken from the end of the bale, the sample will be representative. A hay sampling probe designed by [61 0" T- ■* © CN *-i w.2 O ei -H ; ; ; -H -H r O o CO * ^"S- tA © i-i i-i "5 c < 51 H si ■H -H -H -H ; : w h q iq c cn oo" co © W (N CO N o ■+- c o tH u -SB d H- ■?* -H : : : : : -o ^> N (A V) o 1 in "3 tA CO tt a 3. a> a ca «? tA w .as i ho : : : : -H : c S3 CO CO* CN >s 8 X CO "* 8> 2 • .2-° 1 o © th ■W : -H : : : "5. in OS f" CO CN CN CN o w -o c e o g. 3 1 5= c 4a a , I +* +» -+J +» 4» ^ m Pi d d d d •£ © v% s o o o o ^ o _fl) O (H M ki M d »H O © © a) a> 5 © 3 ■a d Oi Qi Oi U Qi 8 d a h h in" ^ ij u © © © © S © .0.0,0.0 a j3 h- h 5 •e a> •« a> •o-o-o-o 5-d H a O a a 5 a o d £ £ 5 Sh >h Sh hj O O O O O. o H N eo* TjT w to 4* 4* -M +* -** -*» o S o ►J o h3 o ►J o ■J «*► a s? a » © «« ft 4 * cs - w 2 las « 5 2t .2 csgS •S S » S « 2 a * a <-i Z > bo ea ? 3 « a> S » « o a +2 SmwPQfcH * -1— ++oen^= = the Agricultural Engineering Depart- ment and pictured in figure 17, how- ever, is more easily operated than the inexpensive probe pictured in figure 15, and seems to be the sampling de- vice of choice. Information was needed on the vari- ation one might find between bales within a population. Therefore, some individual bales from six lots of hay were analyzed for crude fiber or pro- tein. The coefficients of variation were calculated (table 52). The weighted average of these was 5.94 per cent. The formula given by Snedecor (1946), n - t 2 C 2 /p 2 , was used. Here, n equals the number of bales needed for sam- pling from a population; t equals 2.878; C equals the coefficient of vari- ation found, 5.94 per cent; while p equals the fiducial interval as a per cent of the mean. In this, a fiducial in- terval was chosen which would esti- mate TDN within one percentage unit. Calculations revealed that 19 bales of hay sampled at random from a population would provide a sample which would estimate the TDN within one percentage unit. A population could be any size as long as the hay was from one field, harvested at the same time and at the same maturity stage. Table 52. Coefficient of Variation of Some Hay Bale Populations Number of bales in sample Protein, coefficient of variation Crude fiber, coefficient of variation 45 per cent 7.74 5.05 6.75 2.54 4.32 5.90 per cent 5.24 12 6.45 12 7.83 17 12.. 12.. [62 A field of recently baled hay, there- fore, could be sampled by crossing from corner to corner and sampling 19 bales at random before the bales were gathered and stacked. A stack of bales from one field could be sampled by probing 19 bales at random around the stack at a convenient height, since bales are stacked more or less vertically when they are removed from the field. If a truck load or stack of 20 tons comes from one population, then core samples from 19 bales are needed for a laboratory sample to be representa- tive of the load of hay. However, if two populations are on the truck or stack, separate samples of 19 bales are needed from each source of hay. The cores from the 19 bales are mixed well at the laboratory. Part of the sample (10 grams) is used for a dry- matter analysis. This sample is dried in an oven at 100° C until constant in weight. The remainder of the sample is ground finely in a laboratory mill and duplicate samples taken for modi- fied crude fiber analysis as previously described. The dry-matter results may be valid for a few days only since the moisture content of hay shifts rapidy with changes in weather. Crude fiber anal- ysis, however, is valid for long periods of time, although it must be recalcu- lated on the new dry-matter basis if the moisture content shifts. To simplify the analysis of quality, a table was constructed giving an esti- mate of TDN and digestible protein from moisture and crude fiber content rather than from the regression equa- tions given in table 2. Table 53 was prepared so that TDN and digestible protein could be estimated at a glance. For example, if the analysis showed the alfalfa hay to contain 90 per cent dry matter and 22 per cent crude fiber, then the column headed by 90 per cent dry matter would be used. Checking for 22 per cent crude fiber in this col- umn reveals that the estimated digesti- ble protein would be 15.7 per cent and the estimated TDN would be 54.1 per cent. From a knowledge of hay quality, gained by chemical analysis, a better feeding program can be planned; with high-quality hay, less concentrate and protein can be fed, and conversely pro- duction can be maintained by feeding more concentrates when poor-quality hay has been identified. Results from the Agricultural Ex- tension Service have indicated that palatability was predicted from crude fiber. The low-fiber hay was consumed more readily and there was less feed refusal and waste than with higher fiber hays. To evaluate hay quality critically, the livestock feeder must bear in mind that the utilization of TDN for pro- duction is not as efficient in high-fiber as in low-fiber feeds. In these studies, net energy and digestible protein of hay were compared with those of bar- ley and cottonseed meal to determine which was the most economical feed. Calculations from Morrison (1956) showed that at 16 per cent crude fiber, 1 pound of TDN was equivalent to 0.85 megacalorie of net energy, whereas at 40 per cent crude fiber, 1 pound was equivalent to only 0.63 megacalorie. Furthermore, by taking the available data from Morrison (1956) and plotting the NE/TDN ra- tios against crude fiber level, a very smooth curve was obtained (figure 18). This allowed a calculation of the net energy per unit of TDN in alfalfa hay at various crude fiber levels. Through the use of the system de- vised by Petersen (1932), modified to include NE rather than TDN, table 54 was prepared. 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I I L_ 15 20 25 30 35 CRUDE FIBER, per cent 40 Figure 18. Relation between the crude fiber content of alfalfa hay and the net energy (NE) to total digestible nutrient (TDN) ratio. How to use evaluation factors If cottonseed meal, 41 per cent grade, is higher in price than barley, 44-pound test, and if one must supply supplemental protein to his animals, the evaluation factors should be used. The procedure is to find the proper factors for the hay being evaluated from its dry matter and crude fiber content. Multiply the barley factor by the current price quotation of barley and the cottonseed meal factor by the current quotation on cottonseed meal. Add the two products together to ar- rive at the value of hay. Example: Suppose a hay sample in which one is interested contains 88 per cent dry matter and 28 per cent crude fiber. In the table for 88 per cent dry matter find 28 per cent crude fiber. The evaluation factors are 0.244 and 0.299 for barley and cottonseed meal (CSM), respectively. If the current quo- tations on barley and CSM are $45 and $65 per ton respectively, the calcula- tions shown below are made: price of barley x barley factor: price of CSM x CSM factor: value of hay = sum: The hay is therefore worth $30.42. It should be emphasized that this is not necessarily what one should pay for hay, but the calculation gives the buyer some idea of the relation be- tween asking price and actual value. If the buyer is considering two or more samples of hay, he would calculate the value of each, and, if other factors were satisfactory, purchase the one with the lowest asking price in relation to value. How to use net energy constants If cottonseed meal is no higher in price than barley or if no supplemental protein is needed in the ration, then the hay should be given no extra value for its protein but should be evaluated only on its net energy content. In this case merely multiply the current price quotation for barley by the net energy constant to arrive at the value of the hay in question. Example: In the previous example with a hay containing 88 per cent dry matter and 28 per cent crude fiber the NE constant is 0.55. The following cal- culation is made: price of barley x NE constant: 45x0.55 = $24.75 The value of this hay without the extra value for its protein content is there- fore $24.75 per ton as a source of net energy. Discussion The foregoing system is suggested as a means of taking much of the varia- tion out of visually estimating alfalfa hay value. It should be considered a supplement to existing hay-grading 45x0.244 = $10.98 65x0.299= 19.44 $30.42 [70 standards, since a visual examination all the hay they purchase be analyzed is still needed. for crude fiber. From 10-ton to 400- The California Agricultural Exten- ton lots in a population of hay have sion Service has used this system in the been sampled in a satisfactory manner, field. Sampling procedures have not A system utilizing chemical analysis proven laborious or impractical. The to evaluate hay will be more important laboratory work has been done by com- with pelleted hay than with long, mercial laboratories, dairy coopera- chopped or baled hay. Many of the tives, feed companies, hay grower co- samples used in these data were from operatives and Extension laboratories, digestion trials with pelleted alfalfa. Laboratory work has not been a bottle- Meyer et al. (1959) and Weir et al. neck when the laboratories have been (1959) have reported no differences in alerted so that they can make rapid TDN between pelleted and nonpel- analyses when needed. California live- leted alfalfa hay. It is expected, there- stockmen have received the system well fore, that the results reported here will and many dairymen have insisted that apply to pelleted hay. REFERENCES 6 Heitman, Hubert, Jr., and J. H. Meyer. 1959. Alfalfa meal as a source of energy by swine. Jour. Anim. Sci. 18:796-804. Hull, J. L., J. H. Meyer, G. P. Lofgreen and A. Strother. 1957. Studies on forage utilization by steers and sheep. Jour. Anim. Sci. 16:757-65. Ittner, N. R., G. P. Lofgreen and J. H. Meyer. 1954. A study of pasturing and soiling alfalfa with beef steers. Jour. Anim. Sci. 13:37-43. Kepner, R. A., J. R. Goss, J. H. Meyer and L. G. Jones. 1960. Evaluation of hay conditioning effects. Agr. Engin. 41:299-304. Lofgreen, G. P., and J. H. Meyer. 1956. A method for determining total digestible nutrients in grazed forage. Jour. Dairy Sci. 34:268-73. Lofgreen, G. P., J. H. Meyer and J. L. Hull. 1957. Behavior patterns of sheep and cattle being fed pasture or soilage. Jour. Anim. Sci. 16:773-80. Lofgreen, G. P., J. H. Meyer and N. R. Ittner. 1960. Effects of time and level of supplementation on beef steers fed alfalfa soilage or hay. Jour. Anim. Sci. 19:156-63. Lofgreen, G. P., J. H. Meyer and M. L. Peterson. 1956. Nutrient consumption and utilization from alfalfa pasture, soilage, and hay. Jour. Anim. Sci. 15:1158-65. Meyer, J. H., R. L. Gaskill, G. S. Stoewsand and W. C. Weir. 1959. Influence of pelleting on the utilization of alfalfa. Jour. Anim. Sci. 18:336-46. Meyer, J. H., and G. P. Lofgreen. 1956. The estimation of the total digestible nutrients in alfalfa from its lignin and crude fiber content. Jour. Anim. Sci. 15:543-48. 1959. Evaluation of alfalfa hay by chemical analyses. Jour. Anim. Sci. 18:1233-42. Meyer, J. H., G. P. Lofgreen and F. K. Hart. 1953. The value of certain supplements for beef cattle fed harvested green alfalfa. Jour. Anim. Sci. 12:806-11. 6 The findings reported in the publications listed here were combined, in whole or part, with unpublished findings to form the basis of this bulletin. [71] Meyer, J. H., G. P. Lofgreen and J. L. Hull. 1957. Selective grazing by sheep and cattle. Jour. Anim. Sci. 16:766-72. Meyer, J. H., G. P. Lofgreen and N. R. Ittner. 1956. Further studies on the utilization of alfalfa by beef steers. Jour. Anim. Sci. 15:64-75. Meyer, J. H., W. C. Weir, J. B. Dobie and J. L. Hull. 1959. Influence of the method of preparation on the feeding value of alfalfa hay. Jour. Anim. Sci. 18:976-82. Meyer, J. H„ W. C. Weir, L. G. Jones and J. L. Hull. 1957. The influence of stage of maturity on the feeding value of oat hay. Jour Anim. Sci. 16:623-32. 1960. Effect of stage of maturity, dehydrating versus field-curing and pelleting on alfalfa hay quality as measured by lamb gains. Jour. Anim. Sci. 19:283-94. Morrison, F. B. 1956. Feeds and feeding. 1165 pp. The Morrison Publishing Company, Ithaca, New York. Petersen, W. E. 1932. A formula for evaluating feeds on the basis of digestible nutrients. Jour. Dairy Sci. 15:293-98. Peterson, M. L., G. P. Lofgreen and J. H. Meyer. 1956. A comparison of the chromogen and clipping methods for determining the consump- tion of dry matter and total digestible nutrients by beef steers on alfalfa pasture. Agron. Jour. 48:560-63. Ronning, Magnar, J. H. Meyer and G. T. Clark. 1959. Pelleted alfalfa hay for milk production. Jour. Dairy Sci. 42: 1373-76. Stanford, E. H., L. G. Jones, V. P. Osterli, B. R. Houston, R. F. Smith and A. D. Reed. 1954. Alfalfa production in California. California Agr. Expt. Sta. Cir. 442. 44 pp. Weir, W. C, L. G. Jones and J. H. Meyer. 1960. Effect of cutting interval and stage of maturity on the digestibility and yield of alfalfa. Jour. Anim. Sci. 19:5-18. Weir, W. C, J. H. Meyer, W. N. Garrett, G. P. Lofgreen and N. R. Ittner. 1959. Pelleted rations compared to similar rations fed chopped or ground for steers and lambs. Jour. Anim. Sci. 18:805-14. Woodman, H. E. and R. E. Evans. 1935. Nutritive value of lucerne. IV. The leaf stem ratio. Jour. Agr. Sci. 25:278-86. 15m-3,'62(C5949)A.M.