CALIFORNIA AGRICULTURAL EXPERIMENT STATION BULLETIN 709 OCTOBER 1948 r SWINE FEEDING EXPERIMENTS E. H. HUGHES HUBERT HEITMAN, Jr. THE COLLEGE OF AGRICULTURE UNIVERSITY OF CALIFORNIA • BERKELEY THE DAILY GAIN IN WEIGHT OF PIGS is an important concern to the swine raiser. He must maintain the daily growth of the animals, and he feeds the ration which is used most efficiently by the pigs to produce this weight gain. IF SUBSTITUTES can be found for any part of the ration which will enable pigs to make their gain on fewer pounds of food, or on equal pounds of cheaper food, the swine-raising business is made more profitable. THIS BULLETIN REPORTS the results of four investigations, conducted over a period of years, into this subject of swine feeding. In brief, the investigations show: 1— Up to 30 per cent of cooked or steamed lima beans may efficiently be added to the diet of pigs, thus saving some tankage. 2— About 10 per cent of potato meal can be added to the diet of small pigs weighing less than 100 pounds, and up to 40 per cent to the diet of bigger pigs, to replace part of the barley in the ration. 3— Soybean meal is an excellent plant protein. It may be used to replace animal protein (tankage) in feeding swine. 4— A good, cost-reducing practice is to allow hogs to harvest them- selves a crop of double dwarf milo and cowpeas. THE AUTHORS: E. H. Hughes is Professor of Animal Husbandry, and Animal Husbandman in the Exped- ient sr.ii inn ment Station. Hubert Heitman, Jr. is Assistant Professor of Animal Husbandry, and Assistant Animal Husbandman in the Experiment Station. [2] SWINE-FEEDING EXPERIMENTS E. H. Hughes and Hubert Heitman, Jr. LIMA BEAN EXPERIMENT Many tons of damaged or cull beans are fed annually to livestock in the United States. When fed to hogs most beans are cooked, because they are more palatable and better utilized. Hogs do not like raw beans because of their bitter taste. This taste disappears during the cooking process. Since beans contain about 20 per cent protein they are important as a livestock feed when other protein feeds are expen- sive or difficult to obtain. Damaged or cull beans are available in parts of Cali- fornia. It therefore seemed advisable to secure more information concerning their feeding value than that contained in the available literature. Earlier Studies Show Swine Will Eat Beans If Cooked Thompson and Voorhies (1922) 1 re- ported an experiment in which two parts of barley and one part of cooked beans were fed. The hogs had access to alfalfa pasture. In addition to the pasture, the animals consumed 370 pounds of barley and beans for 100 pounds of gain. Workers at the New Mexico Station (1926) claimed that raw pinto beans proved unsatisfactory as hog feed, while rations containing 60 per cent of cooked pinto beans produced fairly satisfactory results. Edwards and Brown (1928) fed a group of hogs cooked beans and barley with tankage, alfalfa hay and a salt mix- ture. The hogs gained 1.26 pounds per head daily and required 434.5 pounds of 1 See "Literature Cited" for complete data on citations, referred to in the text by author and date of publication. feed for 100 pounds of gain. They re- quired more feed for a pound of gain and grew more slowly than those fed ground corn, tankage, alfalfa hay and a salt mix- ture. The addition of an animal protein to a ration containing barley or corn, beans and alfalfa hay proved advanta- geous. Morrison (1936) stated that "all vari- eties of beans have the same general com- position and feeding value." Lima beans were named along with other varieties like field or navy beans. Tests Used Clean Cull Beans and Good Feeders In the spring of 1943 a quantity of cull lima beans was purchased. The beans were better than average. The amount of dirt varied; some sacks contained very little of it, other sacks up to 10 per cent. The average was probably between 5 per cent and 8 per cent. The average composition of the beans was: moisture 11.7 per cent, ash 4.4 per cent, protein 19.7 per cent, fat 1.2 per cent, starch, sugar, etc., 57.8 per cent, and crude fiber 5.0 per cent. In the three stages of the experiment, beans were included in the rations at either 15 per cent or 30 per cent levels with rolled barley, alfalfa meal, tankage, salt and oyster-shell flour, and were fed in dry lot. The pigs used were good feeders with average initial weights varying from 50 pounds to 85 pounds. They were fed until they weighed from 165 pounds to 210 pounds. They were kept on concrete floors, fed and watered in steel troughs and had access to inside and outside pens. 3] LIMA BEAN EXPERIMENT: FIRST STAGE What percentage of cooked lima beans can be substituted for other protein in the diet of pigs and still maintain their daily gain in weight? . . . How much can tankage be reduced? Table 1: RESULTS OF FIRST-STAGE EXPERIMENTS Lot no. and ration Lot 1: LIMA BEANS, cooked, 15%, tankage 5%, rolled barley 73%, alfalfa meal 5%, salt 1%, oyster-shell flour 1% Lot 2 : LIMA BEANS, cooked, 15%, tankage 2.5%, rolled barley 75.5%, alfalfa meal 5%, salt 1%, oyster-shell flour 1% Lot 3 : LIMA BEANS, cooked, 30%, tankage 5%, rolled barley 58%, alfalfa meal 5%, salt 1%, oyster-shell flour 1% Lot 4: LIMA BEANS, cooked, 30%, tankage 2.5%, rolled barley 60.5%, alfalfa meal 5%, salt 1%, oyster-shell flour 1% Average initial weight pounds 52.0 52.0 52.0 52.0 Average final weight pounds 200.0 195.6 196.0 198.8 Average daily gain pounds 1.24 1.21 1.21 1.23 Feed for 100 pounds gain pounds 383 395 394 388 In this stage four lots of pigs were fed cooked lima beans, rolled barley, tank- age, alfalfa meal, salt and oyster-shell flour. In the first two lots 15 per cent lima beans were included, while the tankage was 5 per cent in Lot 1 and 2.5 per cent in Lot 2. In the rations of Lots 3 and 4 30 per cent cooked limas were included, and the tankage varied as in Lots 1 and 2. To obtain the full 100 per cent in each case, the various differences were made up by the necessary amounts of barley. In this study the average daily gains were similar for all lots, and the amounts of feed required for 100 pounds of gain were not materially different. The pigs in Lots 1 and 4 seemed a little more efficient than those of Lots 2 and 3. It appeared from this study that cooked limas could be fed successfully at either a 15 per cent or 30 per cent level. Further, it was demonstrated that 2.5 per cent tankage in these rations was just as effi- cient as 5 per cent. When the experiment was concluded, the hogs were slaughtered and examined. The carcasses were excel- lent and there was no apparent difference in the quality of the carcasses of the vari- ous lots. New Steam Method Used to Cook Beans The usual cumbersome method of cook- ing beans, by placing them in an open kettle with water and cooking them over a fire, was not adopted in the foregoing study. Rather, the study was used to try out the method of cooking the beans by forcing steam through them. They were processed as follows: A known amount of beans--enough for one day's feeding— was weighed and placed in a clean garbage can; then a known amount of water was added, enough to a little more than cover the [4] beans. They were allowed to soak over night. In the morning they were placed in a round container (Fig. 1) which had a false bottom in which were a number of small holes. The false bottom was about 10 inches above the true bottom. A steam pipe was connected through the center of the can into the bottom. The soaked beans were put in, a cover placed on top and the steam turned on. The beans were steamed for 20 min- utes; then the steam was turned off and the beans allowed to self-cook ap- proximately 5 hours. Some pressure was developed in the cooker because the tem- perature on the top of the beans was slightly over 100° C. In the afternoon the beans were re- moved and allowed to cool. They were fed that evening and the next morning in one trough, while the rest of the ration was fed in a separate trough. Fig. 1. In this home-made steamer the pipe down through the center carries steam to the bottom of the tank. For emptying, the steam pipe is unscrewed and turned out of the way. [5] LIMA BEAN EXPERIMENT: SECOND STAGE How do pigs fare on raw, cooked, and steamed-dried limas? Will steamed-dried beans be as acceptable to pigs as are cooked beans? Table 2: RESULTS OF SECOND-STAGE EXPERIMENTS Lot no. and ration Average initial weight Average final weight Average daily gain Feed for 100 pounds gain Lot 5 (NO BEANS) : Rolled barley, 85.5%; tank- age, 7.5%; alfalfa meal, 5%; salt, 1%; oyster- shell flour, 1% pounds 65.2 66.0 66.0 66.4 pounds 170.4 164.0 198.4 194.4 pounds 1.10 1.00 1.45 1.36 pounds 446 508 380 373 Lot 6: LIMA BEANS, raw, ground, 30%; rolled barley, 60.5%; tankage, 2.5%; alfalfa meal, 5% ; salt, 1% ; oyster-shell flour, 1% Lot 7: LIMA BEANS, steamed, dried 80° C, then ground, 30%; rolled barley, 60.5%; tankage, 2.5%; alfalfa meal, 5%; salt, 1%; oyster-shell flour, 1% Lot 8 : LIMA BEANS, cooked, 30% ; rolled barley, 60.5%; tankage, 2.5%; alfalfa meal, 5%; salt, 1% ; oyster-shell flour, 1% In the second stage of the lima bean ex- periment four lots were used again. The first (check lot) was fed rolled barley, tankage, alfalfa meal, salt and oyster- shell flour, but no beans. In the other lots 30 per cent lima beans replaced 25 per cent of the barley and 5 per cent of the tankage. The beans were fed raw, cooked and steamed-dried. The raw beans were ground in a ham- mer mill and mixed with other feeds. The cooked beans were processed and fed the same as in the first stage. The steamed-dried beans were proc- essed as follows: Dry beans were placed in the cooker and steamed for 30 minutes, then dried at 80° C in a mechanical dryer. These beans were ground and mixed with the other feeds of the ration. Gains Vary from Poor To Good Among Test Lots In this study the pigs in Lots 5 and 6 did not make satisfactory gains. One pig in Lot 5 failed to eat normally for about 10 days. Pigs in Lot 6 apparently did not like the taste of the feed, because they failed from the beginning to consume as much feed as the others. This was true despite the fact that the raw beans had been ground and thoroughly mixed with other feeds. From the standpoint of economical production, Lot 6 was unsuccessful. The rate of gain was poor and the feed re- quired for 100 pounds of gain was 120 pounds more than for Lots 7 and 8. The pigs in Lots 7 and 8 gained rap- idly and economically. [6] When the experiment was concluded the hogs in Lots 7 and 8 were in good condition and ready for market, while those in Lots 5 and 6 were not. There were only two hogs in each of the first two lots that were ready for market. Two facts developed from this study: 1. The raw beans, even though ground, were not economical to feed. (Lot 6.) 2. Steamed, dried and ground beans were just as efficient as cooked beans. (Lots 7 and 8.) LIMA BEAN EXPERIMENT: THIRD STAGE Since steamed-dried beans are acceptable to hogs, can dry heat be used with same results? ... If so, to what tempera- ture must beans be heated to remove bitter taste? Table 3: RESULTS OF THIRD-STAGE EXPERIMENTS Lot no. and ration Lot 9 (NO BEANS) : Ground barley 85.5%, tank- age 7.5%, alfalfa meal 5.0%, salt 1.0%, oyster- shell flour, 1.0% Lot 10: LIMA BEANS, steamed, dried 80° C, ground 30.0%, ground barley 60.5%, tankage 2.5%, alfalfa meal 5.0%, salt 1.0%, oyster- shell flour 1.0% Lot 11: Ration same as for lot 10, except BEANS were air dried in sun on concrete floor after steaming Lot 12*: LIMA BEANS heated to a maximum temperature of 124° C. 30.0%, ground barley 60.5%, tankage 2.5%, alfalfa meal 5.0%, salt 1.0%, oyster-shell flour 1.0% Lot 13* : Same as for lot 12 except BEANS heated to a maximum temperature of 142° C Average initial weight pounds 84.8 86.0 86.0 85.6 86.0 Average final weight pounds 203.6 210.8 211.2 172.4 192.4 Average daily gain pounds 1.54 1.62 1.63 .95 1.21 Feed for 100 pounds gain pounds 388 413 413 594 491 On feed two weeks longer than lots 9, 10, 11. In the second stage it was shown that steamed beans which were then dried and ground were as effective as cooked beans; the bitter taste was eliminated. The beans had been dried in a mechanical dehy- drator. Such equipment is not always available and other methods of drying needed investigation. Dry heat should receive attention. Some preliminary work in the labora- tory showed that heating for 80 minutes in an electric oven at 150° C would re- move the bitter taste. It was now agreed to try feeding beans heated to lower tem- peratures, namely to 124° C and 142° C respectively. [7] Five lots of pigs were used this time. The pigs and equipment used were simi- lar to those in the former stages, but the pigs were heavier and a little older. The beans heated to 124° C were fed to the pigs in Lot 12, while those heated to 142° C were given to Lot 13. Dry-Heating Beans Not As Satisfactory As Steaming As a result, the pigs in Lots 9, 10 and 11 gained rapidly and economically; when the test was concluded they were uniformly well-finished hogs. The pigs in Lots 12 and 13, however, gained more slowly and were not as economical users of their diets as those in Lots 9, 10 and 11. The pigs in Lot 13 were somewhat better than those in Lot 12, but not as well finished as those in the first three lots. This study shows that dry-heating beans even to the fairly high temperature of 142° does not make them as efficient as cooking or steaming them. Conclusions Favor Beans Steamed and Dried for Feed Lima beans— and other varieties, like navy beans, which have similar analy- ses—should be processed when used for hog feeding. They have a bitter taste when raw. This taste is removed when the beans are cooked or steamed. It is re- tained if dry heated unless high tempera- tures are used. (More than 142° C, but 150° C is sufficient.) In these studies cooked or steamed beans were fed successfully at 15 per cent and 30 per cent levels. Raw ground beans and dry heated beans which had been heated to a maximum of 142° C were not efficient in the rations fed. In these studies cooked or steamed cull lima beans fed as a source of energy had a feeding value equal to that of barley and made it possible to feed less tankage. Both methods of processing (cooking or steaming) produced the same results in the rations fed. Cooking beans each day or every other day requires considerable labor. If the equipment is available steaming, then drying and grinding, requires much less labor and the final product is just as val- uable as cooked beans. This method of processing has the additional advantage that the beans may be processed, sacked and fed at any time of the year. All raw beans are deficient in vitamin A and, like barley, their lime content is low. Therefore alfalfa hay or other pas- ture and some form of lime should be in- cluded in a ration containing mostly barley and beans. The addition of prop- erly processed beans, because of their protein content, reduces the amount of other proteins necessary in the ration. Rations containing rolled barley, cooked or steamed (then dried and ground) beans, alfalfa meal, salt and oyster-shell flour and a small amount of tankage re- sulted in economical gains, satisfactory growth and fattening. [8] POTATO MEAL EXPERIMENT Potatoes are fed to hogs as raw, cooked or dry feed in the form of meal or flakes. In most instances they are cooked, and fed with corn, barley, pasture or other crops. They are sometimes fed alone, but are not a balanced diet, be- cause of such deficiencies as calcium, vitamin A and protein. They are more efficient when cooked, or when sun-dried at a temperature of 142° F or higher. Cooking or sun-drying softens the starch grains which makes the starch more di- gestible. In the potato-producing areas of Cali- fornia there are many off-grade, dam- aged or cull potatoes available for live stock feeding. In the southern San Joa- quin Valley producers and others have for several years air-and-sun-dried such potatoes on top of the ground. The pota- toes were then ground and used as cattle and hog feed. The starch grains in this meal, when examined in the laboratory, were found to have changed. The grains had lost their shape, become enlarged, and looked like masses of gelatin. By experimentation it was found that the temperature necessary to accomplish this was 142° F or higher. During the summer months the temperature at the top of the ground in the southern San Joaquin Valley was found to exceed 140° F. When dry, the potatoes are very hard, but may be ground in a hammer mill, sacked and fed as meal. This ground product has about the same appearance or physical structure as coarse wheat mid- dlings. Literature Gives Value of Potatoes As Swine Feed Wilson and Kuhlmann (1924) showed that 339 pounds of cooked potatoes have a calculated value of 100 pounds of corn; pigs gained about half as fast on raw as on cooked potatoes; it took 138 pounds of raw potatoes to equal 100 pounds of cooked potatoes. They suggested that: a) alfalfa be included in the ration dur- ing the winter months or when fed in dry lot; b) potatoes should replace only half of the corn in the ration; c), new pota- toes were more valuable than old po- tatoes. After summarizing experiments in this country and abroad, Morrison (1936), stated that a) 351 pounds of cooked po- tatoes are equal in feeding value to 100 pounds of grain and other concentrates; b) the proportion of cooked potatoes should not exceed four pounds to each pound of concentrates: c) raw pota- toes produce poor results. Morrison further reports that in Ger- many potatoes are sometimes dried and fed in the form of flakes. Sixty Pigs in Tests Over Three- Year Period The potato meal purchased in the open market and used in these experimental studies had the following composition: moisture 13:60 per cent, ash 4.67 per cent, protein 9.26 per cent, fiber 2.40 per cent, ether extract 2.14 per cent and nitro- gen free extract 67.93 per cent. The experiment was conducted in three stages, during the years 1941-1943. Uniform Duroc Jersey, Poland Chinas and cross-bred pigs were used. The aver- age beginning weights varied from about 35 pounds to 55 pounds. Before being put on the experiment, the pigs had been fed normal rations composed of barley, pro- tein concentrates, pasture or alfalfa hay and a simple salt mixture. There were four lots of five pigs each used in each stage. As in the first experiment, the pigs were fed in steel troughs (twice a dav) and had access to inside and outside pens floored with rough concrete. Except for a short period of time during the winter of 1942 they had free access to sunlight. The feed used in the tests was rolled barley, tankage, alfalfa meal, salt, oyster- [9] shell flour, and potato meal except in the them with vitamins A and D. Until they first stage of the experiment when no al- weighed 75 pounds they were given 5 cc falfa meal was fed. In that stage the pigs per head weekly, thereafter 10 cc of cod- were given cod-liver oil which supplied liver oil. POTATO MEAL EXPERIMENT: FIRST STAGE Can potato meal be used to replace some barley in the diet of hogs? . . . How much can be fed before daily weight gain is impaired? Table 4: RESULTS OF FIRST-STAGE EXPERIMENT Lot no. and ration Average initial weight Average final weight Average daily gain Feed for 100 pounds gain pounds pounds pounds pounds Lot 1 (NO POTATO MEAL): Rolled barley 88%, tankage 10%, salt 1%, oyster-shell flour 1% 56.4 203.6 1.32 385 Lot 2: POTATO MEAL 10%, rolled barley 77%, tankage 11%, salt 1%, oyster-shell flour 1%. . 56.6 200.8 1.29 374 Lot 3: POTATO MEAL 25%, rolled barley 60%, tankage 13%, salt 1%, oyster-shell flour 1%. . 56.2 190.0 1.19 403 Lot 4: POTATO MEAL 40%, rolled barley 44%, tankage 14%, salt 1%, oyster-shell flour 1%. . . 56.4 173.2 1.04 422 Lot 1, the check lot, was fed no potato meal. Lots 2, 3 and 4 were fed 10 per cent, 25 per cent and 40 per cent of potato meal respectively. When potato meal was added barley was decreased and tankage slightly increased to keep the protein con- stant. The pigs were on the experiment 112 days. Potato Meal Can Replace Some Barley There was some evidence that as the potato meal was increased, the efficiency of the ration decreased. The pigs fed 40 per cent potato meal gained .25 pound less per head daily than those fed 10 per cent; likewise, the former group con- sumed more feed for 100 pounds of gain than the latter. But, there is probably no significant difference between the results of Lots 1 and 2, even though the pigs fed 10 per cent potato meal (Lot 2) required slightly less feed for their gain than those of Lot 1. There was very little difference in the appearance of the pigs in the various lots, except in the degree of fatness; at the end of the test those animals in Lots 1 and 2 were in better condition than those in Lots 3 and 4. From these results it seemed likely that potato meal could replace part of the bar- ley in the ration without seriously affect- ing the results except in the case of Lot 4 where 40 per cent of potato meal was in- cluded. [10 POTATO MEAL EXPERIMENT: SECOND STAGE Will young pigs gain well if fed potato meal in place of some of their barley ration? . . . What is effect if alfalfa is added to ration? Table 5: RESULTS OF SECOND-STAGE EXPERIMENT Lot no. and ration Average initial weight Average final weight Average daily gain Feed for 100 pounds gain Lot 5 (NO POTATO MEAL) : Rolled barley 83%, tankage 10%, alfalfa meal 5%, salt 1%, oyster- shell flour 1% Lot 6: POTATO MEAL 10%, rolled barley 73%, tankage 10%, alfalfa meal 5%, salt 1%, oyster- shell flour 1% Lot 7: POTATO MEAL 25%, rolled barley 58%, tankage 10%, alfalfa meal 5%, salt 1%, oyster- shell flour 1% Lot 8: POTATO MEAL 40%, rolled barley 43%, tankage 10%, alfalfa meal 5%, salt 1%, oyster- shell flour 1% pounds 35.6 35.6 35.6 35.6 pounds 198.0 197.8 196.4 195.8 pounds 1.22 1.22 1.09 1.09 pounds 351 351 368 368 This test was similar to the former. However, there were three differences: The pigs were younger and the average initial weight was less than that of the first test ; 5 per cent alfalfa was included in this trial; and, finally, the pigs were fed the experimental diet for a longer period of time— 133 days in Lots 5 and 6, 147 days in Lots 7 and 8. The alfalfa meal was excellent in qual- ity, being leafy and green. It supplied vitamins A and D, protein and other es- sential food nutrients. Shortly after the test began, it was found that pigs in Lots 5 and 6 would eat more feed than those in Lots 7 and 8. This was true throughout the major part of the test. While Lots 7 and 8 did well, Lots 5 and 6 did better. All groups were efficient in food utilization and made 100 pounds of gain on less than 370 pounds of the feed mixture. Limit to Potato Meal That Can Be Used While the barley fed was unusually good, it probably was not altogether re- sponsible for the difference in the feed requirement between the second and the first stage of the experiment. It must also be noted that the first stage was carried out during the winter, the second during the summer when pigs are more efficient users of feed. As in the first stage, those pigs fed bar- ley and supplements, and those fed 10 per cent potato meal gained somewhat faster and used their feed a little more efficiently than those fed 25 per cent and 40 per cent potato meal. [in POTATO MEAL EXPERIMENT: THIRD STAGE Since potato meal and western barleys have similar analy- ses, do hogs make equally efficient use of their food nutri- ents? ... Do ages of pigs make any difference in this use? Table 6: RESULTS OF THIRD-STAGE EXPERIMENT Lot no. and ration Average initial weight Average final weight Average daily gain Feed for 100 pounds gain Lot 9 (NO POTATO MEAL) : rolled barley 83%, tankage 10%, alfalfa meal 5%, salt 1%, oyster- shell flour 1% pounds 51.6 51.8 51.6 51.6 pounds 209.2 204.8 210.0 213.2 pounds 1.32 1.29 1.33 1.36 pounds 399 Lot 10: POTATO MEAL 25%, rolled barley 58%, tankage 10%, alfalfa meal 5%, salt 1%, oyster- shell flour 1%. 411 Lot 11: Same as Lot 9 until pigs weighed 100 pounds then the same ration as Lot 10 396 Lot 12: Same as Lot 9 until pigs weighed 100 pounds then: POTATO MEAL 40%, rolled barley 43%, tankage 10%, alfalfa meal 5%, salt 1%, oyster-shell flour 1% 389 Since the first two stages of the experi- ment seemed to indicate a difference in the efficient utilization of feed, depending on the size (weight) of the pigs, the third stage sought to determine whether this was true. The check lot (Lot 9) and the lot fed 25 per cent potato meal (Lot 10) were fed their respective rations throughout the test. Lots 11 and 12 were fed the same as Lot 9 until they weighed 100 pounds. The pigs in Lot 11 were then fed 25 per cent potato meal and Lot 12 was given 40 per cent potato meal. In this part of the experiment each of the four lots was fed the same total amount of feed. Therefore, any difference in the results would be due to the efficiency of food nutrients in the various rations fed. The animals were on experimental ra- tions for 119 days. At the end of the trial period there was very little difference in either the average gain or in the feed required for 100 pounds of gain between the various groups. However, the pigs in Lot 10 did not do quite as well as those of the other groups. In general, the gains were good and the rations were efficient. Except for Lot 10, the animals made their gains on less than 400 pounds of feed for 100 pounds of gain. At the close of the test it was noted that the pigs in each group were a uniformly well-finished, high- quality, thrifty lot of fat hogs. Conclusions: Potato Meal Efficient for Larger Pigs A comparison of the analyses of potato meal and western barleys indicates that there is not much difference in their pro- tein and nitrogen free extract content; that the fat content is similar : that there [12] is more ash in potato meal, and that bar- ley is higher in fiber content. Therefore, it seems logical that there would be little difference in the feeding value of the two products. The result of the potato-meal experi- ment shows that barley is more efficient for the younger pigs, but that this advan- tage disappears as the pigs increase in age. It is possible that the quality of the barley proteins is superior to those of po- tatoes for the younger pigs in the combi- nation of feeds used in the tests. Apparently, it is better management to feed potato meal sparingly to pigs weigh- ing less than 100 pounds; but for hogs beyond this weight, 25 per cent or 40 per cent of the meal may be efficiently utilized. The addition of alfalfa meal in the sec- ond and third stage of the experiment resulted in superior feed utilization as compared to that of the first stage where no alfalfa was given, even though cod- liver oil provided vitamins A and D. Al- falfa contains nutrients other than vita- mins A and D which were apparently necessary in these tests. This feed pro- vided additional protein and apparently other nutrients not supplied in optimal amounts in the rest of the ration. Potato meal dried in the sun at a tem- perature of about 142° F, and then ground, has a feeding value similar to that of barley, for pigs weighing 100 pounds or more. It seems less valuable for pigs weighing below 100 pounds. It should be remembered that this product contains little or no vitamin A; that the protein content is relatively low and should be supplemented with some pro- tein concentrate ; and that for best results it should be fed together with other feeds. [13 SOYBEAN MEAL EXPERIMENT Is soybean meal a good supplement to barley? . . . How does soybean meal compare with linseed meal in rations, where the protein content is the same? Table 7: RESULTS OF EXPERIMENT USING SOYBEAN MEAL TO SUPPLEMENT BARLEY Lot no. and ration f Average initial weight Average final weight Average daily gain Feed for 100 pounds gain Lot 1* (NO SOYBEAN MEAL): rolled barley pounds pounds pounds pounds 85.5%, tankage 7.5%, alfalfa meal 5.0%, salt 1%, oyster-shell flour 1% 56.6 179.0 1.12 407 Lot 2 : SOYBEAN MEAL 7.5%, rolled barley 83%, tankage 2.5%, alfalfa meal 5%, salt 1%, oyster- shell flour 1% 56.4 197.2 1.35 354 Lot 3: Rolled barley 78.5%, tankage 2.5%, linseed meal 12%, alfalfa meal 5%, salt 1%, oyster- shell flour 1% 56.2 199.3 1.30 389 Lot 4: SOYBEAN MEAL 5%, rolled barley 78%, linseed meal 10%, alfalfa meal 5%, salt 1%, oyster-shell flour 1% 56.2 205.8 1.40 552 Lot 5 : SOYBEAN MEAL 12%, rolled barley 81%, alfalfa meal 5%, salt 1%, oyster-shell flour 1% 56.4 206.0 1.40 352 Lot 6: Rolled barley 75%, linseed meal 18%, alfalfa meal 5%, salt 1%, oyster-shell flour 1% . 56.6 187.6 1.19 388 Lot7f: SOYBEAN MEAL 12%, rolled barley 79.5%, alfalfa meal 5%, salt 1%, oyster-shell flour 1%, bone black 1.5% 60.5 205.8 1.51 338 * One pig did very poorly which probably accounts in p tankage contained 60 per cent protein the biological value ma; t The total protein content of the various rations is 13.0 t Only 1 experiment. irt for the j f have been or 13.1 per oor results ii low due to in cent. i this group lproper proc . While the essing. [ 14 SOYBEAN MEAL EXPERIMENT Soybean meal, an important plant pro- tein feed, has not been used extensively by swine producers in California. While it has been on the market in the Middle West for a number of years, it has not been available here until recently. Many feeding experiments have been conducted in which this protein concentrate has been fed with corn, but little is known about its value as a supplement to barley. The feeds used in this experiment were a good grade of rolled barley, soybean meal with a guaranteed protein content of 43 per cent, tankage with a protein con- tent of 60 per cent, linseed meal with a protein content of 28 per cent, and al- falfa meal made of good quality alfalfa hay. Salt, oyster-shell flour and bone black were also used. Well-grown, uniform and healthy feeder pigs were employed in this experi- ment. Feeding conditions (steel troughs, concrete floors, etc.) were as in the former experiments. Water was always available. Soybean Meal Good When Other Nutrients are Added From the results as presented in Table 7, the indications are that soybean meal supplements barley unusually well. The pigs in Lots 2, 4, 5 and 7 gained rapidly and were efficient in the utilization of the feed consumed. No doubt the alfalfa meal in all the rations was an important factor, because it furnished vitamins A and D, protein and other food nutrients. The animals in Lot 5, fed soybean meal at a 12 per cent level, became stiffened during the latter part of the experiment. This led to the addition of bone black to the same diet in Lot 7. The bone black resulted in reduced lameness and in increased effi- ciency of the diet. While the protein content of the rations fed in Lots 3 and 6 (linseed mealj was the same as the rest, the feed required for 100 pounds of gain was more than for all other lots except Lot 1. Linseed meal under the conditions of this experiment was less efficient than soybean meal. For some reason the pigs in Lot 1 did poorly. The rate of gain was slower than ex- pected, and they were less efficient than the other groups. The tankage used was a standard 60 per cent product though it was very dark in color. It is possible that some of the protein may have been injured in the manufacturing process. Not all of the pigs in the experiment were on feed the same length of time. When they attained a weight of about 200 pounds they were removed from the ex- periment. The experiment showed that soybean meal at the levels fed and in combination with other feeds was an excellent supple- ment to barley. Soybean meal was more efficient than linseed meal in rations where the protein content was the same. It is difficult to explain the poor results of the pigs in Lot 1 fed tankage and alfalfa meal as the protein supplements. Appar- ently the biological value of the tankage was low, because other experiments con- ducted at this station, under similar con- ditions, showed that pigs fed this ration gained more rapidly and were more effi- cient in utilizing their feed. 15 "HOGGING DOWN" EXPERIMENTS Is it practical in California to hog down grain sorghums? . Will pigs gain better on milo or on milo and cowpeas?. Can milo be used to finish hogs in the field? In the Middle West the practice of "hogging down" corn has been used for many years. This method of harvesting has been demonstrated with such crops as peanuts in the South, oats and peas in some northern states, and peas in the Northwest. California livestock producers have been slow in utilizing this means of reducing labor costs— one reason being that barley is the principal grain crop and does not lend itself to such practices as well as corn or some other cereals like the grain sorghums. An increase in the grain-sorghum pro- duction in California, and a shortage of farm labor during the war were the rea- sons why a study of hogging down milo was begun in the summer and fall of 1942. Other Writers Report on Success of Hogging Down Morrison (1936) reports that hogging down corn is a successful practice, but for best results some supplements like rape, rye, soy beans or cow peas should be planted with the corn, or the hogs should be allowed access to alfalfa or clover pas- ture. If pasture is not available, about two pounds of tankage should be pro- vided daily for each pig. Shade, shelter and water should be provided. Anderson and Marston (1925) con- cluded from their experience that the practice of hogging down sorghums was wasteful when there was considerable rainfall, because of tramping in the muddy fields. At the Nebraska Station (1939) hog- ging down sorghums resulted in the pro- duction of 425 pounds of pork per acre (average of two experiments). The pigs were fed some supplement in addition to the harvested grain. Since there is often very little rain in the great valleys of California until No- vember, and since the ground is often firm and smooth, there appeared to be a definite need for additional information on hogging down the grain sorghums. From the results of all hogging down operations in the corn belt there was proof that some legume crops grown with the corn proved economical and profit- able. The best legume crop to plant with the milo for our conditions seemed to be cowpeas. The variety used were "black- eyes," often called "beans." The experiments were conducted three times during the years 1942, 1943 and 1944. In each year one group of animals was allowed to feed on a milo field, while another group fed on a field where cow- peas were planted in addition to the milo. The pigs used were farrowed in the spring and fed normal rations until they weighed about 50 pounds. After that they were forced to get along on a small amount of grain, and had free access to green pasture until the experiment began. When the experimental crops were ready for harvest, the pigs were thrifty but not fat. More Pork Per Acre From Milo and Cowpeas The average pork produced per acre for the three years was 432 pounds. In 1944 nearly four inches of rain fell dur- ing the harvesting process, which re- sulted in the loss of some feed due to tramping. As a result of less feed the hogs lost weight. There was considerable variation in initial weights and rates of gain for the three years. The pigs gained more rapidly in the milo-cowpeas lots than in the milo lots. In 1942 the milo and cowpeas were [16] Table 8: WEIGHT GAINS MADE ON MILO COMPARED WITH GAINS ON MILO AND COWPEAS Time Number of acres Number of pigs Days on experi- ment Average initial weight Average final weight Average daily gain Pork produced per acre DOUBLE DWARF MILO Summer of 1942 1943 1944 0.5 3.0 0.5 11 41 8 21 35 28 pounds 92.6 85.1 113.0 pounds 110.2 116.7 135.2 pounds 0.84 0.90 0.80 pounds 409 429 357 DOUBLE DWARF MILO AND COWPEAS 1942 1943 1944 1.5 3.0 3.0 33 41 47 21 24 28 pounds 92.5 85.1 113.9 pounds 113.0 117.9 145.8 pounds 0.98 1.37 1.51 pounds 451 448 500 Table 9: GAINS MADE BY HOGS FATTENED ON ROLLED BARLEY AND MILO IN THE FIELD Year Number of pigs Average initial weight Average final weight Average daily gain Feed required for 100 pounds gain DOUBLE DWARF MILO Fall Of 1943 41 pounds 116.7 pounds 167.0 pounds 1.67 pounds 343 DOUBLE DWARF MILO AND COWPEAS 1943 40 pounds 117.9 pounds 181.5 pounds 1.68 pounds 334 planted in the same rows. During 1943 and 1944 they were planted separately, two rows of double dwarf milo alternat- ing with two rows of cowpeas. It was interesting to watch the pigs when they were turned into the milo and cowpea fields. They first circled the fields, then began eating the cowpeas. They did not begin feeding on the milo until the next day. The average of pork produced per acre from milo and cowpeas was 466 pounds, and for milo alone 398 pounds— a difference of 68 pounds per acre. Foraging and Self-Feeding Practical Finish for Hogs When the crops in the 1943 test were harvested there was some forage left in the fields. The pigs were neither fat nor heavy enough for market. It seemed logi- [17] cal therefore to self -feed them in the fields. To provide lacking grain, self-feeders were set up in one corner of each field and filled with rolled barley or ground milo, without protein supplement. The results are shown in Table 9. That year the pigs weighed less than 120 pounds when this phase of the experi- ment began. Both lots of pigs gained rap- idly. Because of the forage still left in the fields, both required less than 350 pounds of grain for 100 pounds gain. The ani- mals in the milo-cowpea field and those in the milo field did about equally well in this part of the experiment. The practice of hogging down crops could be used by some California pork producers as a profitable and sound ven- ture. Experiments show that it is better to use some legume crops like cowpeas to- gether with milo, than to use milo alone. Because of the possibility of early rains, the crops should be planted early and harvested while the fields are dry. Feeders weighing 85 pounds or more are more efficient in hogging down practices than are smaller pigs. In case some forage is left in the field and the pigs are not fin- ished, the practice of self-feeding rolled or ground barley or other grains is good. Other crops, like corn and cowpeas, may be hogged down just as successfully as milo and cowpeas. It is equally pos- sible that other legume crops may prove as efficient as cowpeas used as an addition to milo. LITERATURE CITED Anderson, B. M. and W. H. Marston 1925. Swine feeding investigations, 1923-1924. Kansas Agr. Exp. Sta. Cir. 118. Edwards, W. E. J. and G. A. Brown 1928. Supplement cull beans with animal protein. Michigan Agr. Exp. Sta. Quarterly 11. Morrison, F. B. 1936. Feeds and feeding. 20th Edition Morrison Publishing Co., Ithaca, N.Y. Nerraska Agricultural Experiment Station 1939. 42d annual report, pp. 1-59. Thompson, J. I. and Edwin C. Voorhies 1922. Hog feeding experiments. California Agr. Exp. Sta. Bui. 342. Wilson, C. P. and J. L. Lantow 1926. Bean feeding. New Mexico Agr. Exp. Sta. Bui. 155. Wilson, James W. and Arthur H. Kuhlmann 1924. Pototoes as a feed for fattening pigs. South Dakota Agr. Exp. Sta. Bui. 209. 15m-10,'48(A9(525) 18 •2« AGRICULTURE . . • Contains brief, easy-to-read progress reports of agricultural research, and is published monthly by the University of California College of Agricul- ture, Agricultural Experiment Station. FIELD CROPS ORCHARDS TRUCK CROPS LIVESTOCK CALIFORNIA AGRICULTURE offers information useful to the farmer and food processor, together with announce- ments of other publications dealing with farm subjects as they are issued by the College of Agriculture. Upon your request, your name will be added to the mailing list to receive CALIFORNIA AGRICULTURE with- out cost. Send your name and address to: California Agriculture, Publications Office, College of Agriculture, University of California, Berkeley 4, California