UNIVERSITY OF CALIFORNIA COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY, CALIFORNIA THE DIGESTIBILITY OF BROWN ALFALFA HAY, SESAME MEAL, AND ARTICHOKE SILAGE AS DETERMINED FOR RUMINANTS A. H. FOLGER BULLETIN 575 MAY, 1934 UNIVERSITY OF CALIFORNIA BERKELEY, CALIFORNIA SUMMARY The stack-burned alfalfa, commonly known as "tobacco" or brown hay, used in these trials, is approximately equivalent to average alfalfa hay in nutritive value. The excellent results ascribed to it by feeders arise probably from its greater palatability and the consequent fact that the animals consume more of it than of ordinary hay. The sesame meal available for this trial closely resembles average prime cottonseed meal in feeding value, being higher in all nutrients ex- cept the carbohydrates. It contained 35.8 per cent digestible protein and 77.2 per cent total digestible nutrients; while the corresponding values for average prime cottonseed meal are 33.4 per cent and 75.5 per cent respectively. In palatability the two appear to be equal. Artichoke silage, a succulent carbohydrate roughage, is similar in es- sential characteristics to corn silage. Though slightly lower in total digestible nutrients, it is, in general, probably a more economical feed than corn silage, since it originates as a by-product. [2] THE DIGESTIBILITY OF BROWN ALFALFA HAY, SESAME MEAL, AND ARTICHOKE SILAGE AS DETERMINED FOR RUMINANTS 1 A. H. FOLGER 2 INTRODUCTION To aid the feeder of livestock in his search for low-priced feeds, and to assist industry in marketing its by-products, the University of Cali- fornia, through its Division of Animal Husbandry, has from time to time conducted tests to determine the nutritive values of new materials which, because of their chemical composition and volume, may prove important. In arriving at feed value, there are two important considerations : the composition, as determined by chemical analysis, and the amount of each constituent actually digested by the animal. To ascertain the for- mer is relatively simple, but to arrive at the coefficient of digestibility for a given feed is more tedious and complicated. In 1926, the University published, in Agricultural Experiment Sta- tion Bulletin 409, 3 the digestible composition of dried orange pulp and dried raisin pulp ; and in 1927, in Bulletin 439, 4 the results of trials with the dried pulps of the pineapple, lemon, and olive. The following pages contain the results of experiments to find the feeding values of brown or "tobacco" alfalfa hay, sesame meal, and artichoke silage. The methods used were essentially those formulated by the National Research Coun- cil for the determination of digestion coefficients. 5 They are described in detail in Bulletin 409 mentioned above. Wether sheep were used. They are especially suited to digestion trials, being small and easily handled; the feces are easy to collect and process for analysis. The coefficients of digestibility determined by their use are applicable to cattle. 6 1 Received for publication January 9, 1934. 2 Superintendent of Official Advanced Registry Tests. 3 Mead, S. W., and H. R. Guilbert. The digestibility of certain fruit by-products as determined for ruminants. Part I. Dried orange pulp and raisin pulp. California Agr. Exp. Sta. Bui. 409:1-12. 1926. * Mead, S. W., and H. R. Guilbert. The digestibility of certain fruit by-products as determined for ruminants. Part II. Dried pineapple pulp, dried lemon pulp, and dried olive pulp. California Agr. Exp. Sta. Bui. 439:1-11. 1927. s Forbes, E. B., and H. S. Grindley. On the formulation of methods of experimen- tation in animal production. Natl. Research Council Bui. 6, part 2 (33) :l-28. 1923. 6 Armsby, H. P. The nutrition of farm animals, p. 603-605. The Macmillan Co. New York. 1930. [3] 4 University op California — Experiment Station An alfalfa hay of known digestibility was fed with the sesame meal. In order to prepare the animals for each trial, a 10-day preliminary feeding period was used. During the 15 days following this period, feces were collected for analysis. RESULTS OF DIGESTION TRIAL WITH BROWN ALFALFA HAY When hay with a high moisture content (30 to 50 per cent) is stacked, fermentation occurs, accompanied by marked rise in temperature. The result is a product brown in color, with a mild tobacco odor and the mois- TABLE 1 Total Feed Consumed and Total Feces Collected Animal number Hay fed Feces collected grams 15,921 13,163 13,958 11,165 11,657 grams 17,723 2 13,320 3 . 14,566 11,995 4 5 14,510 TABLE 2 Chemical Analyses of Feces and Feed Animal number and feed analyzed Dry matter Crude protein Nitrogen-free extract Ether extract Crude fiber Feces: 1 per cent 31.57 31.71 32.70 32.15 29.99 89.82 per cent 4.31 4.54 4.70 4.06 3.82 14.58 per cent 10.46 10.32 10.81 11.23 10.45 39.88 per cent 1 34 1.60 1.31 1.39 1.28 1.35 per cent 11.47 2. 10.93 3. 11.62 4 11.75 5 10.87 Feed: Brown alfalfa hay 24.67 ture content of normal hay. Many feeders of livestock prefer this "to- bacco" or "brown" hay to that cured in the usual manner (that is, with about 20 per cent moisture when stacked) . They believe that the animals relish it more and that it is more nutritious. In another experiment (the results of which have not been published) , designed to study the causes of spontaneous combustion, some brown alfalfa hay of excellent quality was produced. The many inquiries re- ceived concerning the feeding value of this material led to a digestion trial, the results of which appear in tables 1, 2, 3, and 4. As shown by table 4, the digestibility of all constituents in the brown alfalfa hay, except that of the crude fiber, was lower than that of aver- age hay. These results might be expected. During fermentation there is Bul. 575] Alfalfa Hay, Sesame Meal, Artichoke Silage TABLE 3 Coefficients of Digestibility of Brown Alfalfa Hay Animal number Dry matter Crude protein Nitrogen-free extract Ether extract* Crude fiber 1 per cent 60.87 64.27 62.05 61.61 58.50 per cent 67.09 68.50 66.17 69.85 67.15 per cent 70.80 73.81 71.81 69.89 67.53 per cent -10.50 -19.93 - 1.54 — 11 03 -18.44 per cent 48.24 2 55.17 3. 51.54 4 49.81 5 46.16 61.46 67.75 70.77 Negative 50.18 * The digestibility of any constituent is determined by subtracting from the amount found in the feed that remaining in the feces; ordinarily less remains in the feces than was present in the feed and a positive figure for digestibility is obtained. A negative coefficient occurs when the amount in the feces is greater than that present in the feed. This is most likely to occur where the constituent is present in a feed in small quantities as is the case with the ether extract in the brown alfalfa hay (table 2). Negative coefficients are not infrequently found for ether extract for the reason that the feces contain unresorbed bile residues and other ether-soluble products of excretion. These increase the amount of ether extract present and minimize its apparent digestibility by concealing the amount actually remain- ing after the digestive process. In the present instance the total of the ether-soluble substances present in the feces is greater than was present in the feed, thus giving a negative result. TABLE 4 Coefficients of Digestibility of Brown Alfalfa Hay as Compared with Average Alfalfa Hay Constituents Dry matter Crude protein Nitrogen-free extract Ether extract Crude fiber Brown alfalfa hay per cent 61.46 67.75 70.77 50.18 Average alfalfa hay Henry and Morrison* average of all analyses per cent 60 71 72 38 43 Mead and Guilbertf determinations per cent 63.31 77.00 73 45 20 31 48.49 * Henry, W. A., and F. B. Morrison. Feeds and feeding. 18th ed. 770 p. Appendix Table III. Henry- Morrison Co., Madison, Wis., 1923. t Mead, S. W., and H. R. Guilbert. The digestibility of certain fruit by-products as determined for ruminants. California Agr. Exp. Sta. Bui. 409:1-12. 1926. a loss of crude protein and nitrogen-free extract, as a result of oxidation, while the value of the relatively indigestible crude fiber is enhanced by the bacterial action that tends to convert it into a more digestible form. A comparison of the total digestible nutrients of brown alfalfa hay with other feeds appears in table 11. RESULTS OF DIGESTION TRIAL WITH SESAME MEAL Sesame cake or meal, though used for feeding livestock in European countries for many years, is relatively new in California. The seed is grown extensively in China and other Oriental countries. Now that re- cent favorable exchange rates have stimulated its importation into Cali- fornia, where the oil is extracted, thousands of tons of residual meal are available for the feeding of livestock. University of California — Experiment Station TABLE 5 Total Feed Consumed and Feces Collected in Trial with Sesame Meal Animal number Alfalfa hay Sesame meal Feces grams 13,620 11,804 13,620 13,620 12,244 grams 3,405 3,405 3,405 3,405 3,405 grams 18,268 2 12,094 3 17,833 4 5 16,558 16,189 TABLE 6 Chemical Analyses of Feces and Feed Animal number and feeds analyzed Dry matter Crude protein Nitrogen-free extract Ether extract Crude fiber Feces : 1 2 per cent 29.81 33.51 29.56 33.00 32.34 89.82 93.24 per cent 4 00 4.98 4.39 4.50 4.44 14 58 39.30 per cent 9 88 10.36 9.49 11.22 10 81 39.88 27.44 per cent 1 25 1.65 1.19 1.31 1.28 1.35 9.01 per cent 9.86 10 34 3 4 9.48 10.30 5 Feeds : 10.23 24.67 4.89 TABLE 7 Coefficients of Digestibility of Sesame Meal* Animal number Dry matter Crude protein Nitrogen-free extract Crude fiber 1 per cent 76.98 82.47 76.40 68.59 per cent 93.25 per cent 76.75 per cent 23.58 2f 3 4 5 89.35 92.18 89.31 88.80 71.09 65.45 90.04 81.09 9.15 Average 76.11 91.02 75.52 50.97 * As no coefficient of digestibility of ether extract for the brown alfalfa hay was available (table 3), it was impossible to compute, by the usual method, the similar coefficient for sesame meal. In other feeding qualities, this meal is comparable to such well-known feeds as cottonseed meal, coconut meal, and peanut meal. The digestibility of the fats in these feeds ranges from 90 to 100 per cent. To afford a basis of comparison with other feeds, a digestion coefficient of 90 per cent might conservatively be assumed. The figure for fat in table 11 was estimated in this manner. t Number 2 did not eat as well as the other sheep and gave negative results. Because new methods of extracting oil have somewhat changed the character of the meal, and because California stockmen, as indicated by the large number of inquiries received, are unfamiliar with its nutri- tional value, the Division of Animal Husbandry decided to determine digestion coefficients for its various nutrients. The meal was fed with the brown alfalfa hay mentioned above, since this hay was of known digestibility. Probably the sesame meal, being Bul. 575] Alfalfa Hay, Sesame Meal, Artichoke Silage 7 high in protein, would show a slightly higher value if fed with a low- protein hay. The data are given in tables 5, 6, and 7. A comparison of the total digestible nutrients of sesame meal with other common feeds will be found in table 11. RESULTS OF DIGESTION TRIAL WITH ARTICHOKE SILAGE When the globe artichoke (Cynara scolymus) is harvested for human consumption, the stalks and inferior heads are left in the field, consti- TABLE 8 Total Feed Consumed and Feces Collected Animal number Artichoke silage (dry*) Feces (dry) 1 grams 7,438 6,727 8,249 9,820 4,614 grams 3,054 2 2,678 3 3,474 4. 4,465 5 1,851 * Weigh-back deducted. TABLE 9 Chemical Analyses of Feces and Feed Animal number and feed analyzed Dry matter* Crude protein Nitrogen-free extract Ether extract Crude fiber Feces : 1 . per cent 30.20 per cent 14 8 13.6 14.5 12.1 15.2 6.82 per cent 32.4 33.8 32.9 33 9 32.9 45 81 per cent 2.9 2.6 2.9 2.4 3.1 1.68 per cent 20.6 2 ... 22.9 3 21.4 4 25.9 5 19.6 Feed: Artichoke silage. . 27.15 * In this trial the feces were taken to the drying oven immediately on collection, and the dry weights recorded after removal from- the oven. tuting a serious impediment to the preparation of land for a subsequent crop. In Monterey county alone, this residue amounts to more than 140,000 tons annually. Certain dairymen have used silos to preserve this material for cow feed. The animals eat it with relish, consuming as much as 30 to 40 pounds per day, and maintain their milk flow. It has also been used for wintering beef cattle and sheep. Because of the interest in this feed, and the lack of information con- cerning it, a digestion trial was conducted. Artichoke silage obtained from a large dairy near Salinas was fed to the five sheep previously 8 University of California — Experiment Station used. The data on this trial appear in tables 8, 9, and 10; and table 11 compares this with other common feeds. The best known and most widely used silage is that made from corn ; for purposes of comparison between this and the artichoke silage the TABLE 10 Coefficients of Digestibility of Artichoke Silage Animal number Dry matter Crude protein Nitrogen-free extract Ether extract Crude fiber 1 per cent 58.94 60.19 57.89 54.53 59.88 per cent 14.47 20.66 12.26 20.07 11.36 per cent 71.04 70.57 69.80 66.40 71.29 per cent 35.35 39.22 30.64 36.09 28.36 per cent 67.41 2 3. 66.61 66.04 4 5 56.21 70.69 58.29 15.76 69.82 33.93 65.39 TABLE 11 Total Digestible Nutrients of Various Common Feeds Compared with the Feeds Used in these Trials Feed Total dry matter in 100 pounds Digestible nutrients in 100 pounds Crude protein Carbo- hydrates Fat Total* Alfalfa hayf Brown alfalfa hay Prime cottonseed mealf Sesame meal Coconut mealf Barleyf Corn silagef Artichoke silage pounds 91.4 89.8 92.2 93.2 90.0 90.7 26.3 30 2 pounds 10.6 9.9 33.4 35.8 19.9 9 11 0.3 pounds 39.0 40 6 24.3 23.2 44.2 66.8 15.0 15 pounds 0.9 0.5J 7.9 8.1 3.0 1.6 0.7 2 pounds 51.6 51. 75. 77. 70. 79. 17 15.8 * Total includes fat times the factor 2.25. t Henry, W. A., and F. B. Morrison. Feeds and feeding. 18th ed. 770 p. Appendix Table III. Henry- Morrison Co., Madison, Wisconsin. 1923. X For a comparison between the nutritive value of brown alfalfa hay and that of the other feeds in table 11, a coefficient of digestibility had to be assumed for the ether extract because, as shown in table 3, this value was negative, a result clearly not in keeping with the facts. following digestion coefficients for corn silage are taken from Henry and Morrison : 7 dry matter 66 per cent, crude protein 51 per cent, nitrogen- free extract 71 per cent, ether extract 82 per cent, and crude fiber 65 per cent. 7 Henry, W. A., and F. B. Morrison. Feeds and feeding. 18th ed. 770 p. Henry- Morrison Co., Madison, Wis., 1923. 12m-5,'34