CONTENTS Summary . . . . . . . . . . . . . . . . . . . . . . .0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Early Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..~. Factors Involved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Free Gossypol Tolerance . . .i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .; v Protein Quality and Lysine Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fiber. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pathology oi Gossypol Poisoning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . It: Trials with Different Meals . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . Growth—Trial 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11‘ Feed per 100 Pounds Gain—Trial 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . , . . . . . . .- . . . . . . . . . . . . . . . . . . Growth—Trial 2 . . . . . y. . r . . . . . . . . . V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Feed per 100 Pounds Gain—Trial 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3; Aureomycin plus Vitamin B12 with Meals . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cottonseed and Soybean Meals as Protein Supplements . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . Recommendations . . . . . . . . . . . . . . . . f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .; Mixed Rations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Free-choice Feedings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . h . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .Literature Cited . . . . .A . . . . . . . . . . ..' . . . . . . . . . . . . . . . . . . . . . . . . ..’ . . . . . . . . . . . . . . . . . . .._ . . . . . . . . . . . . . . SUMMARY This bulletin contains the results oi studies involving protein quality, lysine availability, amino l content and gossypol tolerance as they relate to the use oi cottonseed meal in swine rations. These s also include the pathology oi gossypo-l poisoning in pigs and the results oi ieeding trials with cotto e meal made by diiierent manufacturing processes. ‘g, .-.-_ ‘i’ Newer methods now available ior processing and evaluating the protein quality and gossypol co’ have provided a way ior making a cottonseed meal that can be used saiely in complete ieed mixturi in protein supplements ior swine. t When the complete ration ior hogs contains not more than 0.01 percent oi iree gossypol. the pig‘ such rations will make good gains. No pigs have died nor have any pigs showed the slightest sympt oi cottonseed meal iniury in these experiments when the ration contained 0.01 percent or less oi l gossypol. This means that cottonseed meals containing 0.04 percent or less oi iree gossypol are saiei swine ieeding. The rations ied contained liberal amounts oi good quality protein. The rations ied were improved by adding aureomycin and vitamin B12. Studies reported in this bulletin lead to the conclusions that swine producers can include cotto 1' meal in rations ied to pigs with good results. Methods oi iormulating such rations also are includ OTTONSEED MEAL, when used properly, is an i excellent source of protein for use in swine flions. If the swine produced in the 13 South- ' States alone were fed adequately balanced cations, they would require an amount of cotton- m meal equal to the production of about 2 llion acres of cotton, figuring the average 11d at two-thirds of a bale per acre. __ Many tests on the use of cottonseed meal swine rations have given poor results. These ults were due largely to the quality of the eal or the way in which it was used. During ‘ ent years, information has been developed at Texas Agricultural Experiment Station on j- specifications of superior quality cottonseed and the factors which must be considered ’ its production, Lyman, Chang, and Couch 953), Chang et al. (1955), Baliga and Lyman A1957) and Lyman and Baliga (1958). The pro- am has been directed by Carl M. Lyman. _ The protein supplement part of the well- _lanced swine rations is the principal feedstuff the hog farmer has to buy, and since cotton- meal is rich in protein, and since it is a j- that is available in. a wide area at all times, t is important that we should know more about ; use in hog rations. EARLY OBSERVATIONS I Cottonseed meal can now be used in swine ‘tions with excellent results. This statement not true a few decades ago. In fact, early gs indicated that one might never be able to cottonseed meal in practical hog rations. For example, Curtis and Carson (1892), at ;_ Texas Agricultural Experiment Station, ted that pigs died in 6 to 8 weeks from the ' e of first feeding of cottonseed meal. _ At the Kansas Station, Georgeson and Burtis 895) found that when the ration contained (percent cottonseed meal, the pigs died in 3 48 weeks after they were started on the test l0I1. ‘I Curtis (1895) at the Iowa Station found the toxic to pigs when the pigs had eaten 27 , 33 pounds per pig; '1 spectively, professor, Department of Animal Husband- _;; head, Department of Biochemistry and Nutrition; a head, Department of Veterinary Pathology. ults from the feeding of cottonseed meal to‘ Use m‘ Cottonseed flleal in Swine Haliens Fred Hale. (arl M. lumen and Hilton A. Smithi‘ Dinwiddie (1903) at the ArkansasStation found that pigs receiving 0.6 to 0.8 pound daily of cottonseed meal died in 34 to 64 days after the test started. Hale (1930) at the Texas Station found that rations containing a maximum of 9 percent cot- tonseed meal couldbe fed to fattening hogs as well as to breeding animals without producing undesirable effects. This report showing the condition under which cottonseed meal could be used safely and profitably was soon verified by other investigators and the way was open for the limited use of cottonseed meal in swine rations. Robinson (1934) found that cotton- seed meal which was toxic at levels of 18 to 20 percent of the ration “was not toxic when fed at a level of 10.5 percent of rations containing some tankage. In these years, cottonseed meal meant hy- draulic cottonseed meal since this was the major processing method at the time. Today there are a few straight solvent cottonseed meals with free gossypol content too high for the products to be used safely in swine rations at the 9 per- cent level. Such meals are excellent for cattle and sheep and should be fed only to ruminating animals. At the Texas Station, Lyman, Holland and Hale (1944) studied the processing variables in the hydraulic method of cottonseed oil ex- traction and found that by the control of the variables, time, temperature and moisture con- tent, meal of very low gossypol content could be produced in commercial mills. Several tons of meal containing 0.024 percent free gossypol were manufactured and fed to hogs at levels as high as 25 percent of the ration. No symptoms of gossypol toxicity were observed, but protein quality in this meal was not high and con- sequently the growth rate of the pigs was poor. Cottonseed processing studies required bet- ter analytical methods. The first colorimetric method for the determination of free gossypol was developed by Lyman, Holland and Hale (1943). This development provided a new, ac- curate and fast method for the determination of free gossypol in cottonseed meal and hastened the way for producing a high quality cotton- seed meal for swine and poultry. The microbiological method for the deter- mination of amino acids in natural feeds was developed at the Texas Station by Kuiken, Lyman and other co-workers (1943). This method has 3 -~ ance level for gossypol in swine rations. been used extensively in protein quality evalua- tion studies. Harris (1947), with the use. of isopropyl alcohol as the solvent, produced a solvent-ex- tracted cottonseed meal at the Texas Station which gave good results when fed to pigs. More recent studies on the use of cottonseed meal in swine rations are reported in this bulle- tin. FACTORS INVOLVED Cottonseed meals manufactured under dif- ferent processing conditions differ over a wide range with respect to their nutritional value as protein supplements for hogs. Because of this fact, feeding trials in which cottonseed meal is A compared with other protein supplements are worthless unless information also is made avail- able concerning the processing conditions or the chemical characteristics of the meals. Essen- tially the characteristics of a superior quality cottonseed meal for use in swine rations are: (1) it must be low in free-gossypol, 0.04 percent or less is recommended; and (2) it must contain high quality protein. High nitrogen solubility is a good indication of high protein quality in cottonseed meal. Seventy-five percent or higher nitrogen solubility in 0.02 N sodium hydroxide is recommended. Free Gossypol Tolerance If cottonseed meal of high free gossypol con- tent is used as the sole protein supplement for hogs for a long time, some of the animals are almost certain to die and the percentage loss is likely to be high. It is, therefore, im- portant to know what is the maximum safe toler- Table 1 gives the results of a test in which the level of free gossypol was varied from 0 to 0.028 per- cent. A- 15.5 percent protein ration was used in this test. Free gossypol was supplied by mixing two cottonseed meals, one of very low and one of high free gossypol content. The composition of the rations for all groups ex a the control was: milo, 76.5 percent; mixed tonseed meal, 9 percent; soybean oil meal, percent; alfalfa leaf meal, 3 percent; limest 0.5 percent; salt, 0.5. percent; and aurofac ( taining aureomycin and vitamin B12), 0.5 r cent. The ration for the control group contai 18 percent soybean meal and p0 cottonseed Q The pigs used in thesé=tests were purebf Durocs bred and raised by the Texas Agri tural Experiment Station. They represented * kind and weight often purchased as feeder for commercial feeding. Both barrows and g were used. The pigs were kept and fed in dividual pens with concrete floors and with * outside concrete pen adjacent to the pen in the feeding shed. Both the inside and ou =, pens were 4 feet by 8 feet in size. Each inside the barn contained an individual f feeder and each outside pen contained an E dividual water trough. The pens were clea and washed daily. _ The results (Table 1) indicate that, un the conditions of this experiment, 0.01 pe ~ free gossypol in the ration is a safe level. ; animals which received 0.01 percent free goss" or less showed no gossypol toxicity sym" and the gain was as good or almost as go, in the control group where the ration conta” soybean meal as the sole protein supple l. There were no death losses with 0.015 pe g free gossypol in the dietybut two pigs sho. gossypol toxicity symptoms as indicated by se thumping or labored breathing. This u- breathing was due to partial congestion ofi lungs with fluid. Deaths occurred in all q receiving more than 0.015 percent free gossj Informal reports made at the third col ence on Processing as Related to Nutritive r of Cottonseed Meal, which was held at the S0 ern Regional Research Laboratory in New. leans in 1953, indicated a lack of agree g’ among investigators concerning the highest , of free gossypol which should be considered for swine. The discovery that gossypol tole TABLE 1. EFFECT OF FREE GOSSYPOL LEVEL IN THE DIET ON GROWING-FATTENING PIGS. 70-DAY TEST Crude protein level oi diets 15.5% I Item Percent gossypol in diet None a .0013 .0025 .007 .010 .015 y .019 .022 Group number 1 2 3 4 5 6 7 8 Number oi animals‘ 8 8 8 8 8 8 8 8 Initial weight. pounds 57.6 57.6 57.8 57.6 57.6 57.7 57.6 57.7 Final weight. pounds 192.4 192.4 181.3 187.3 188.8 184.8 178.7’ 185.8’ Average daily gain. pounds 1.92 1.92 1.76 1.85 1.87 1.81 1.702 1.83” Feed per 100 pounds gain 367.4 377.5 374.0 348.2 364.2 361.7 364.5 351.4 Number oi deaths None None None None None None 1 2 Number oi animals which lived. but showed gossypol toxicity symptoms None None None None None 2 None ‘Pigs ied in individual pens. ’For animals remaining at close oi test. 4 TABLE 2. COMPOSITION OF RATIONS Item 15% protein rations 30% protein rations 'on number 1 2 3 4 5 6 7 8 ttonseed meal. pounds 0 1.6 3.2 4.8 0 1.6 3.2 4.8 Lybean meal. pounds 13.0 11.8 10.8 8.0 52.4 51.4 50.0 47.4 o. (grain sorghum). pounds 81.0 80.6 80.0 81.2 41.6 41.0 40.8 41.8 ‘. alta leat meal, pounds 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 _estone. pounds 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 p: t. pound 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 otac. pound 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Wvels vary with the amount and quality of the rotein in the diet offers a sound basis for in- preting this apparent ‘discrepancy. A Table 2 gives the ration used in a gossypol- lerance test with two levels of protein. Gos- ‘lypol was supplied in the form of hexane-ex- acted cottonseed meats prepared in a commer- l ial mill with a minimum of heat. The meal con- ined 0.64 percent free gossypol and 38.25 per- fent protein. The protein content of the soybean eal was 47.94 percent. The results of the test are shown in Table . 'With a 15 percent crude protein diet, 0.01 Percent free gossypol did not produce symptoms "V. gossypol toxicity, but gave slightly lower ‘rowth rate than the control group receiving no ossypol. Levels of free gossypol above 0.01 percent resulted in toxicity symptoms and the ’eath of some animals in each group. These ‘sults are in agreement with those obtained the first experiment (Table 1). In sharp contrast, no animal receiving the 134 percent protein ration showed any symptoms "f gossypol toxicity. When these animals were § aughtered at the termination of the experiment, ‘to internal symptoms could be found by a quali- Lied veterinarian who examined them. Table 4 shows the amount of gossypol con- "eriod. Animals which died on the 15 percent rotein ration had consumed up to 39.6 grams s. gossypol. Every animal in the groups fed 30 ‘ rcent protein rations and either 0.02 or 0.03 per- ABLE s. umed by individual animals during the test cent gossypol in the ration consumed more gos- sypol than did any of those which died on the 15 percent protein ration, yet none died and none showed any gossypol toxicity symptoms. The relationship between gossypol tolerance level and the amount and quality of the protein in the ration has been substantiated by reports from three different laboratories. In addition to the investigation with swine at the Texas Agricultural Experiment Station, Cabell and Earle (1956) conducted experiments with rats and Earle and Stevenson (1957) used swine. Protein Quality and Lysine Availability The nutritional value of a protein depends on the kind and relative amounts of amino acids which it contains and on the digestibility of the protein. Table 5 shows the amino acid com- position of cottonseed meal and the grains, corn and milo, which are generally fed with this pro- tein supplement. The amino acids which are likely to be deficient in farm rations for swine are tryptophan, methionine and lysine. Cotton- seed meal is a good source of tryptophan and a fair source of methionine, but is deficient in lysine. Lysine is thus the limiting amino acid in a cottonseed meal-corn or cottonseed meal- milo type of ration. Perhaps of more importance is the fact that a portion of the lysine in cottonseed meal cannot be digested, absorbed and utilized by the ani- mals. Lysine availability is, therefore, a major factor in determining the quality of protein in cottonseed meal. Perhaps no other major protein EFFECT OF PROTEIN LEVEL IN THE RATION ON GOSSYPOL TOLERANCE IN GROWING-FATTENING PIGS. 84-DAY TEST Standard protein level. 15% C.P. High protein level. 30% C.P. Item ‘X, gossypol in diet ‘Z, gossypol in diet l 0 .01 .02 .03 0 .01 .02 .03 ation number 1 2 3 4 5 _ 6 7 8 umber ot animals‘ 8 8 8 8 8 8 8 8 'tial weight. pounds 58 58 58 58 58 58 58 58 A al weight. pounds i: _ 204 190 170’ 1353 188 191 186 177 verage daily gain. potgnds‘ 1.74 1.57 1.31 1.16 1.55 1.58 1.52 1.42 eed per 100 pounds gain. pounds 366 376 424 461 387 379 381 384 mber 0t deaths None None 2 4 None None None None umber oi animals which lived. but ‘ showed gossypol toxicity symptoms None None 3 2 None None None None ‘gs ted in individual pens. I remaining animals. , remaining animals. TABLE 4. GOSSYPOL CONSUMED BY INDIVIDUAL PIGS 157, protein ration .027, gossypol .03"/° “gossypol 30% protein ration .02°fi, gossypol .03 "/, gossypol Total Total Total ‘ Total :- Pig gossypol Pig gossypol Pig gossypol Pig gossyp number consumed. number consumed. number consumed, number consume - t: grams grams grams 910ml ‘ 93 51.8 23‘ 29.6 30 51.1 65.4 3’ 35.7 51” 50 45.4 40 62.9 104‘ 39.6 20’ 26.4 21 45.2 79 64.4 39’ 31.1 ' 130‘ 35.6 81 40.9 70 57.1 j -l06 53.6 75’ 44.5 125 44.9 74 62.0 f 151 51.6 55 54.5 46 43.2 87 71.4 44’ 28.9 68 52.3 123 42.7 133 66.2 .. 110‘ 24.9 36‘ 24.0 126 41.8 77 50.9 ‘ Average 39.7 38.1 44.4 62.5 ‘Animals which died with symptoms oi gossypol poisoning. ’Animals which showed gossypol toxicity symptoms but did not die. “Removed from lot 3 weeks alter test started because oi leg iniury and general unthriitiness. concentrate varies as much in protein quality as does cottonseed meal. Such. variations are largely the result of variations in manufacturing conditions. Variations in protein quality in cottonseed meal can be measured in small animal feeding trials with rats. Table 6 shows the wide varia- tions found in different samples. Wide varia- tions in lysine availability in a collection of cot- tonseed meal are shown in Table 7. There is as much variation in protein quality among differ- ent samples of cottonseed meal made by any one processing method as there is between different manufacturing procedures. The exact conditions used in any process are of primary importance. A. modification of the Cannon (1944) rat protein repletion test described by Cabell and Earle (1954) was used for the protein quality evaluations. The procedure for the determina- tion of lysine availability was described by Ba- liga and Lyman (1957). Lyman, Change and'Couch (1953) studied the chemical characteristics of cottonseed meal as these are related to nutritional value. A relationship was found between protein quality and nitrogen solubility in 0.02 N sodium hydrox- ide and protein quality. This test has been very TABLE 5. ESSENTIAL AMINO ACID CONTENT OF COTTONSEED MEAL. CORN AND MILO useful as a mill control in the production superior quality cottonseed meal. ‘ Several commercial milling processes s’ now followed for the production of low goss i high protein quality cottonseed meal for use‘? swine and poultry rations. Fiber , Growing and fattening pigs do not dip crude fiber as well as do cattle or sheep. s, rate of gain is depressed when the fiber con_' of the ration for fattening pigs is 7.5 per or more (Bohstedt et al., 1933). The amo_ of feed required for a given gain, however, creases regularly with rations containing m than about 4.5 percent crude fiber (Lat et aL, 1938). Cottonseed meal, as now manufactured, i tains a considerable amount of hulls. The p‘ duction of cottonseed meal with less hulls W06 yield a product with higher protein content Q lower crude fiber. Such a meal would be ' efficient as a protein supplement for swine. 1; Soybean meal with a 50 percent crude p tein guarantee and with less than 3.5 perc crude fiber is now being sold for use in poul and swine rations. Cottonseed meal Corn Milo Amino acid In the In crude In the In crude In the sample. protein. a sample. protein. sample. prote‘ to O O O O O O O O O O ' Arginine 4.38 11.02 0.37 4.60 0.45 Histidine 1.07 2.70 0.22 2.73 0.22 Isoleucine 1.59 ’ 4.01 0.33 ' 4.10 0.46 Leucine 2.46 6.20 0.95 11.80 1.22 Lysine 1.67 4.20 0.27 3.35 0.24 Methionine 0.59 1.49 0.18 2.24 0.18 Phenylalanine 2.09 5.25 0.42 5.22 0.50 Threonine 1.38 3.47 0.31 3.85 , 0.41 Tryptophan 0.63 1.59 0.087 1.17 0.140 Valine 1.98 4.98 0.43 5.34 0.58 Protein content 39.61 8.05 10.25 6 TABLE 6. PROTEIN QUALITY IN DIFFERENT SAMPLES OF COTTONSEED MEAL AS DETERMINED BY RAT PROTEIN REPLETION TESTS Meal Rat protein repletion Type oi processing value. grams gain number in weight in 10 days 1 Solvent extraction 39.3 2 Prepress solvent 38.7 3 Solvent. extraction 36.1 4 Hydraulic press 24.4 5 Slow speed screw press ~ 22.6 6 Prepress solvent 20.9 7 High speed screw press 18.2 PATHOLOGY or GOSSYPOL POISONING1 The pigs that died came from lots receiving free gossypol in an amount between 0.02 t0 0.03 percent of the total ration. The 0.01 percent or less level of free gossypol did not result in the death of any pigs. The animals that died had been on the {gossypol ration 38 to 79 days, with the exception iof 2 which survived until the 93rd day. Even Iii-the highest level of gossypol used was not neces- isarily lethal. Many pigs showed only retarded irowth when marketed at the usual age of 6 to months. y, In the seriously poisoned animals, signs of i, lness were typically apparent 2 to 6 days, or, lxceptionally, as long as 1 month. The out- nding symptom was always dyspnea, with giolently labored respirations which stockmen ll thumping. Progressive weakness and emaci- ftion were accompanied by a good appetite al- 4 ost until death. p Widespread congestion and edema were t ylient post-mortem lesions. The lungs and liver 1°" markedly congested in all cases; the kid- I "eys, spleen and lymph nodes, in many. I Large amounts of fluid often were encoun- in the pleural, pericardial and peritoneal i vities. gses, was commonly so extensive that a frothy gyuid was visible in the trachea. In accordance rther information may be found in paper by Smith, BLE 7. VARIATION IN LYSINE AVAILABILITY IN DIFFER- f‘ SAMPLES OF COTTONSEED MEAL AS DETERMINED a Y RAT FEEDING TESTS AND NITROGEN SOLUBILITY . I‘ Id!‘ .. . Nitrogen viii 9P1 Type of Lyslpe solubility s}? processing av.“ 31' in 0.02 tron ability _, N N a0H Experimental solvent extraction 3,‘. 80.7 83.1 Screw press 82.6 87.7 Prepress solvent 76.9 75.9 Commercial meal not identified 68.1 64.5 Screw press . 55.3 53.7 Screw press 53.2 53.7 Screw press 50.7 50.9 Edema of the lungs, present in all with accepted principles, the edema was con- sidered to have been dependent on passive con- gestion and venous stasis. The latter conditions were attributed to a progressively failing heart on the basis of both symptoms and lesions, Figure 1. The occurrence of gross pathologic lesions resulting with rations containing 0.02 to 0.03 percent free gossypol are listed in Table 8. All livers were congested grossly, with at least a suspicion of intralobular necrosis or other degenerative changes. The livers generally were reddish with the lobular architecture possibly more prominent than normal. In the pig, this is normally conspicuous because of the distinct interlobular septa. Microscopic examination re- vealed a startling change in all the livers (Figure 2). While in 5 pigs the destruction was only partial, the remaining 13 had almost no viable parenchymal cells. In these, only a narrow rim of hepatic cells remained at the extreme peri- phery of each lobule. The remainder of the lobular space was filled with blood, although a scattered reticulum of Kupffer cells appeared to be intact. a While extensive areas of the skeletal muscles frequently were pale or almost white, it was difficult to demonstrate microscopically any change beyond an abnormal variation in the size Figure 1. Degenerative changes in heart muscle. TABLE a. cnoss PATHOLOGIC LESIONS OBSERVED IN 1s PIGS__ FED BATIONS CQNTAINING 0.02 TO 0.00 PERC FREE GOSSYPOL ~ g; 4 n-I IQ (D Animal number 6 7 9 14 15 16 o-I Q 11 12 13 ® Subcutaneous edema Hydrothorax Congestion and edema oi lungs Hydropericardium Dilatation oi heart Hypertrophy oi heart Hydroperitoneum Edema of gallbladder Edema of lymph nodes Congestion (and necrosis) of liver Congestion of kidney “White muscles" Icterus ++++ + +++++ + +++ ++++ ++++ + + +++ + + ++ + ++++++++++ u: of certain fibers some being atrophied, others hypertrophied (Figure 3). The lesions portrayed are nearly identical to the lesions described by West (1940) in dogs fed poisonous amounts of cottonseed meal, ex- cept that gastroenteritis was more prominent in the dogs and petechial and ecchymotic hemor- rhages were numerous. The centrilobular de- struction of liver cells was less pronounced in the dogs. In contemplating the almost unprecedented changes found in the liver, the question arises Cne part of the lobule has undergone necrosis and is being replaced with blood. 8 Figure 2. Early lesion in liver. +++++++++++ +++ €l'+++ ++++ + +++ "l" +++-l‘ G ++ + + ++++++ +++++ + ++++ ++++ +++++++++++ +¥++ + +++++ ++++ +++ ++++++ ++++_a+++++ +++ + +1, whether this degree of hepatic injury resul from the anoxia consequent upon congestion stasis of blood, or whether a direct hepatoto" action must be attributed to the gossypol. advocated has been the theory that increas blood pressure in the intralobular capillar“ destroys the hepatic cells by pressure necros Without attempting an unequivocal answer this problem, certain similar and possibly lated disorders of dietetic nature are the w,‘ intriguing, as Well as the most perplexing. Hove and Seibold (1955) fed a diet low; protein (soybean meal), markedly deficient’), vitamin E and containing cod-liver oil, of whit highly unsaturated fatty acids are characteriif, constituents. After 1 to 4, months on this di the animals usually died and, at necropsy, show a “hemorrhagic necrosis” of the liver simi Q in most respects to the hepatic condition cribed to gossypol. Cirrhosis developed in .j that lived for 6 months. The authors consider the livers to be comparable with those produ a by Obel (1953), who described a porcine known as hepatosis diaetetica which occurs ‘ turally in Sweden and Northern Europe a which was susceptible of experimental rep). duction by the combined deleterious effects (1) inadequate dietary protein (brewer’s yea which is deficient in the sulfur-containing amid acids), (2) deficiency of vitamin E and (_ presence in the diet of considerable amou", (6 percent) of cod-liver oil with its highly u saturated fatty acids. The similarities betw“, the lesions arising from excessive gossypol y those described for natural or experimental ca‘ of hepatosis diaetetica are seen in the necro and blood-filled hepatic lobules and in the l; comitant presence of extensive edema in prl tically identical situations andin the prese of retrograde changes in the skeletal and card {j i musculature Which, while called by differ, names, appear microscopically to have at -t the degenerative features in common. Howev) certain notable differences between the cases; g gossypol poisoning and those which Obel (19 and Hove and Seibold (1955) found to re from dietetic imbalances are readily appar, both in clinical and post-mortem aspects. f ABLE 9. CHEMICAL ANALYSES OF COTTONSEED MEALS USED IN FEEDING TRIALS 1, 2 AND 3 Protein Free ‘ -Meal description content. 5X, gossypol. 7., crew press. S-51 - 40.38 0.020 Screw press. S-59 37.44 0.027 crew press. S-514 ~ 40.00 0.027 Ilsopropanol extracted 46.12 0.013 ydraulic 42.25 0.04 ‘egossypolized ' 39.80 0.04‘ Approximate value. A special analytical method is required ior accurate determination on this type oi meal. The method became available after this work was completed. TRIALS WITH DIFFERENT MEALS Six different cottonseed meals, all with a free ossypol content not exceeding 0.04 percent, were c. ed in three tests as the sole protein supplement §t0 growing-fattening pigs without symptoms of gossypol toxicity. These tests included com- mercial screw press and hydraulic meals, a pecial process degossypolized meal and an ex- erimental meal made by solvent extraction with '0propyl alcohol. Results of these tests give urther evidence that low gossypol cottonseed eal does not produce unfavorable physiological Qeffects on hogs. Table 9 shows the chemical composition of gtheomeals used in these tests. The rations used in feeding trial 1 are given in Table 10 and the esults are shown in Table 11. One of the con- jclusions drawn from this test is that aureomycin lus vitamin B12 significantly increased the * "1 owth rate of the groups fed screw-press and ‘propanol-extracted cottonseed meals. A second . inding of importance is that a screw-press meal plus aureomycin and vitamin B12 gave growth ates and feed efficiency equal to those obtained 5 ith meat scraps. liGrowth-Trial 1 l. The group of pigs fed the control ration ontaining meat scraps (lot 7) made highly ignificantly greater average daily gains (131.01) than the combined groups of pigs on ations containing cottonseed meals without auro- ac. , There was no significant difference in aver- Age daily gains between the pigs receiving the fntrol ration (lot 7) and the pigs receiving ttqhseed meal S-514 plus aurofac (lot 4) or the roup of pigs receiving the isopropanol-extracted ttonseed meal plus aurofac (lot 6). The pigs receiving cottonseed meal 8-514 I lus aurofac (lot 4)“ =made highly significantly eater average daily gains (P:.01) than the oup of pigs receiving the same meal without i e aurofac (lot 3). The same highly signifi- Int difference was shown for the pigs receiving opropanol-extracted meal plus aurofac (lot 6) ver the group of pigs receiving the isopropanol- extracted cottonseed meal without the aurofac (lot 5). No significant difference was found be- tween combined groups of pigs receiving screw- press cottonseed meal without aurofac (lots 1, 2 and 3) and the pigs. receiving the isopropanol- extracted cottonseed meal (lot 5) without the aurofac. * The pigs receiving the isopropanol-extracted olfcottonseed meal plus aurofac (lot 6) made sig- nificantly greater average daily gain (P=.Oi5) than the group receiving the screw-press cotton- seed meal plus aurofac (lot 4). Feed per 100 Pounds Gain—Trial 1 There was no significant difference in feed required per 100 pounds of gain between the control pigs receiving meat scraps in the ration (lot 7) and the combined groups of pigs receiving cottonseed meal rations (without aurofac (lots 1, 2, 3 and 5). Neither was there a significant difference in the feed required per 100 pounds of gain between the control group receiving meat scraps in the ration (lot 7) and the group re- ceiving cottonseed meal S-514 plus aurofac (lot 4). However, the pigs in lot 6 receiving iso- propanol-extracted cottonseed meal used signifi- cantly less feed per 100 pounds of gain (P1105) Figure 3. Degenerative changes in skeletal muscle. TABLE 10. COMPOSITION OF RATIONS- USED IN FEEDING TRIAL 1 1 Group number 1 2 3 4 5 6 a Ground milo. pounds 79 77 79 79 _ 81 81 l} Screw press C.S.M.‘ S-51, pounds 16 - Screw press C.S.M. S-59. pounds 18 _ Screw press C.S.M. S-514. pounds l6 16 Isopropanol extracted C.S.M.. pounds 14 _ 14 ‘a Meat scraps. pounds f‘? ‘l Alfalfa leaf meal, pounds 3 3 3 3 3 ‘ "' 3 ~ Limestone, pounds 1.5 1.5 1.5 1.5 1.5 1.5 Salt, pound 0.5 0.5 0.5 0.5 0.5 0.5 Auroiac’. pound 0 0 0 0.5 0 0.5 ‘C.S.M.=cottonseed meal. ‘Contained 1.8 grams aureomycin and 1.8 milligrams vitamin B12 per pound. than did the pigs in lot 7 (the control group) re- ceiving meat scraps. The pigs in group 6 receiving cottonseed meal S-514 plus aurofac used significantly less feed per 100 pounds of gain (P:.05) than the pigs in lot 5 receiving the same meal Without the aurofac. The pigs receiving isopropanol-extracted cottonseed meal plus aurofac (lot 6) used highly significantly less feed per 100 pounds of gain (P1101) than the pigs receiving the same meal without aurofac (lot 5) . Table 12 shows the rations used in feeding trial 2 and the results of this test are given in Table 13. Two different screw-press cottonseed meals, S-51 and S-59, gave growth rates equal to those obtained with soybean meal. The sample of hydraulic meal was not as good as these two screw-press meals, but gave better growth rate and feed efficiency than meat scraps. The addi- tion of aureomycin plus vitamin B12 increased growth rate and improved feed efficiency in the _ test with hydraulic cottonseed meal. Growth-Trial 2 No significant difference was found in the average daily gain of the combined groups of pigs receiving the expeller-processed cottonseed TABLE 11. PERFORMANCE DATA OF PIGS FED MEAT SCRAPS AND COTTONSEED MEALS MADE BY DIFFERENT PROCES _p FEEDING TRIAL l‘ the aurofac (lot 3). ‘ meals, S-51 and S-59, plus aurofac (lots 1 and; and the pigs receiving soybean meal plus the t, rofac (lot 5). ‘ The pigs receiving hydraulic-processed tonseed meal plus aurofac (lot 4) made sir cantly greater average daily gains (P=.05) t the pigs receiving the hydraulic meal with The combined groups of pigs receiving peller-processed cottonseed meals plus aurok (lots 1 and 2) made highly significantly grea average daily gains (P=.01) than did the.,~_ receiving meat scraps plus the aurofac (lot 6) “j The group of pigs receiving soybean oil m 1 plus aurofac (lot 5) also made highly sip cantly greater gains (PIIOI) than did the receiving meat scraps plus the aurofac (lot 7 Feed per 100 Pounds Gain—Trial 2 There was no significant difference in g average feed required per 100 pounds of :- between the combined groups of pigs recei g expeller cottonseed meal, S-51 and S-59, ~§ aurofac (lots 1 and 2) and the pigs in lo receiving hydraulic-processed meal plus auro Neither was there any significant difference? the feed required per 100 pounds of gain tween the combined groups of pigs receiv: Lot 1 Lot 2 Lot 3 Lot 4 Lot 5 Lot 6 Lot ' Screw Screw Screw screw Iso- 150' a ‘i Item press propanol t~ press press press as M propanol extracted Me C.S.M. . C.S.M. C.S.M. s_5'14' extracted C s M S-51 S-59 S-514 + aurofac. C.S.M. + aurofac. Number oi pigs per lot 6’ 6“ 63 7 7 7 Length of test. clays 84 84 84 84 84 84 Average final weight, pounds 195.6 191.8 186.8 214.8 191.4 221.1 Average initial weight. pounds 68.6 68.6 68.3 66.7 66.7 66.7 Total gain, pounds 127.0 3123.2 118.5 148.1 124.7 154.4 Average daily gain. pounds 1.51 1.46 1.41 1.76 1.48 1.84 Feed per 100 pounds gain, pounds 411.0 394.3 406.6 375.0 406.0 365.4 Total feed eaten. pounds 3132 2914 p 2891 3889 3545 3950 ‘Complete ration mixed and fed in self-feeder. “Contained 1.8 grams aureomycin and 1.8 milligrams vitamin B12 per pound. “One pig removed from test because o! unthriitiness. 10 TABLE 12. COMPOSITION OF RATIONS USED IN FEEDING TRIAL 2 ‘ Group number 1 2 3 4 5 ’ 6 und milo. pounds 79 77 80 80 81 84 1 I ew press C.S.M. S-51. pounds 16 _;- ew press C.S.M. S-59. pounds 18 draulic C.S.M.. pounds " 15 15 qybean oil meal. pounds 14 _ at scraps, pounds 11 1 .- a leaf meal. pounds 3 3 3 3 3 3 i .4“ pound 0.5 0.5 0.5 0.5 0.5 0.5 q‘stone. flour. pounds _ 1.5 1.5 1.5 1.5 1.5 1.5 ' fac‘. pound 0.5 0.5 0.5 0.5 0.5 ntained 1.8 grams aureomycin and 1.8 milligrams vitamin B12 per pound. peller cottonseed meal, S-51 and S-59, plus meal supplied by the Buckeye Cotton Oil Company urofac (lots 1 and 2) and the group of pigs are given in Table 14. In this test, degossypolized eiving soybean oil‘ meal plus the aurofac. cottonseed meal gave growth rates and feed i efficiency almost as good as those obtained with soybean oil meal. The degossypolized cottonseed meal used in this test was manufactured by the use of an aromatic amine to combine with and inactivate free gossypol. No significant difference was found in the eed required per 100 pounds of gain between the figs receiving hydraulic-processed cottonseed _eal (lot 3) and the pigs receiving hydraulic- rocessed cottonseed meal plus aurofac (lot 4). "~' Unfortunately, the three feeding trials re- ported were carried out before the nitrogen solubility test using 0.02 N sodium hydroxide Was developed and, consequently, information on the solubility of the protein in these samples is not available. The combined groups of pigs receiving ex- ller cottonseed meal, S-51 and S-59, plus auro- (lots 1 and 2) used highly significantly less eed per 100 pounds of gain (P=.01) than did ti» group of pigs receiving meat scraps plus the ‘urofac (lot 6). ‘i The free gossypol content of the ration con- taining degossypolized cottonseed meal ~(lot 2) was 0.0096 percent. The difference in gain and in feed required per 100 pounds of gain between the two lots was not significant. Although the p pigs fed the ration containing 24 percent degossy- - - - - polized meal made good gains, a ration with a his Zgfioiflguaofifglassggcfiggfigg Ssigzggizgggllyniggsl part of the cottonseed meal replaced with soybean .,., per 100 pounds of gain (11:01) than did gnnesiirllgzvgéiiliishave a better distribution of essential E Pigs receiving hydraulic-processed cotton- ‘f d meal plus aurofac (lot 4) used highly signifi- ‘ntly less feed per 100 pounds of gain (P=.01) p: did pigs receiving meat scraps plus aurofac 0t 6). _ e pigs receiving meat scraps plus the aurofac lot 6). _ t There was no significant difference in the AUREOMYCIN PLUS VITAMIN B12 required per 100 pounds of gain between’ 'W1TH MEALS figs receiving soybean oil meal plus aurofac (lot ) and the pigs receiving hydraulicmrocessed The addition of aurofac containing aureo- lttonseed meal plus the aurofac (lot 4)_ mycin plus vitamin B12 to rations in which cot- - tonseed meals (hydraulic, screw-press or p " Results of a comparative test with soybean isopropanol-extracted) were used as the protein meal and a sample of degossypolized cottonseed concentrate consistently resulted in more rapid V: BLE 13. PERFORMANCE DATA OF PIGS FED SCREW PRESS COTTONSEED MEAL. HYDRAULIC COTTONSEED MEAL. ’_ SOYBEAN OIL MEAL AND MEAT SCRAPS. FEEDING TRIAL 2 oup number 1 2 a 4 s s >1“ 71;. Screw press Screw press Hydraulic Hydraulic Soybean Meat e, "m “Pplemem C.S.M. S-51 C.S.M. s-se C.S.M. C.S.M. meal scraps lurotac‘ Added Added Added ' Added Added ber oi pigs 7 7 B’ 6’ 7 6’ . - erage initial weight. pounds 502 501 445 443 501 _ 432 ‘ erage final weight. pdlurlds 1448 1490 968 1150 1457 978 -_ erage total gains. pounds 946 989 523 707 956 A 546 ierage daily gains. pounds 1.75 1.83 1.13 1.53 1.77 1.18 verage total teed consumption. pounds 517 548 367 464 513 413 ‘ed per 100 pounds gain. pounds 384 388 427 394 375 454 'derle's B12 concentrate with aureomycin contains 1.8 grams oi aureornycin and 1.8 milligram of vitamin B1, per pound. ne pig was removed irom lots 3. 4 and 6 because of sickness followed by general unthriitiness. 11 TABLE 14. DEGOSSIIPOLIZED COTTONSEED MEAL AND SOYBEAN MEAL AS PROTEIN SUPPLEMENTS FOR GROW- ING-FATTENING PIGS, FEEDING TRIAL 3 Degossy- Performance data soybean pohzed meal cottonseed meal Lot number I II Number of pigs per lot‘ 8 8 Length of test. days 7U 7U Average final weight. pounds 201 193 Average initial weight, pounds 69 69 Total gain. pounds 132 124 Average daily gain. pounds 1.88 1.75 Total feed eaten. pounds 3788 3640 Feed per 100 pounds gain. pounds 358.7 370 Composition of rations ‘X, ‘X, Milo 74.5 70.0 Soybean meal 20 0 Cottonseed meal 0 24 Alfalfa leaf meal 3 3 Ground limestone 1.5 1.5 Salt 0.5 0.5 Aurofac’ 0.5 0.5 ‘Pigs were fed in individual pens. ’Contained 1.8 grams aureomycin and 1.8 milligram vitamin B12 per pound. gains. This conclusion was verified by further tests not included in these tables. COTTONSEED AND SOYBEAN MEALS AS PROTEIN SUPPLEMENTS Table 15 shows the results obtained in a test in which a protein supplement containing soybean meal was compared with a supplement in which TABLE 15. USE OF LOW GOSSYPOL-HIGH PROTEIN QUALITY COTTONSEED MEAL‘ AND SOYBEAN MEAL IN SUPPLEMENTS FOR GROWING-FATTENING PIGS” Group number 1 2 Composition of protein supplements. pounds Cottonseed meal 37 0 Soybean meal 37 74 Alfalfa leaf meal l9 19 Limestone 4 4 Salt 1 1 Aurofac3 2 2 Growth rate and feed efficiency‘ Number of pigs. 8 8 Average initial weight. pounds ' - 64.7 64.8 Average final weight. pounds 219.6 214.1 Average daily gain. pounds 2.01 ‘ 1.94 Feed required per 100 pounds gain: Milo. pounds 341.3 322.2 Protein supplement. pounds 43.5 50.4 Total feed. pounds 384.8 372.6 ‘The cottonseed meal used in this test contained 0.033% free gossypol and had a nitrogen solubility of 74.1%. “Protein supplement and milo were fed free choice in self- feeders. _ “Aurofac (1.8 grams aureomycin, 1.8 milligrams B12 per pound). ‘Differences in gain and feed utilization were not statistically significant at the 5"/., level. Pigs in each group fedqin ~ individual lots. = 12 - chances are that the pigs will overeat a straigli - of crude- protein recommended in Table 16. 50 percent of the soybean meal was replaced wi a low gossypol, high-protein quality cottonse meal. ' The pigs were fed in individual pens for 1 days. The straight soybean meal supplement slightly more palatable than the cottonseed-so‘ bean meal mixture since the pigs getting j soybean meal supplement ate 7 pounds mo '5 supplement per pig during the test. The pigs getting the mixed siupplemen, gained 0.07 pound more per pig per day, but t difference was not significant. A There was no significant difference in =3 required per 100 pounds of gain for the t. groups, although the pigs getting the soybe meal supplement required 0.12 pound less fe per pound of gain. The pigs getting the cottonseed-soybean m I mixture ate 2.2 percent less supplement per 10 pounds of gain, which indicates that when thes feeds are fed free-choice in self feeders, th soybean meal supplement before they would f. cottonseed-soybean meal mixture. This w0ul_ tend to make the cottonseed-soybean meal mixtur more economical to feed. a ' RECOMMENDATIONS Two methods of feeding are used in swin production. In the first method, the feeds us are mixed completely for self-feeding or the mi 1 ture can be fed by hand, usually twice per day- In the second method, a protein supplement mi ture is formulated to be fed in one compartmeng along with corn or milo in a second compartmen? of a self-feeder, free-choice. A third compartment of the self-feeder is used frequently for a miner mixture. a Mixed Rations Table 16 shows the percentage of crude pro-ff tein needed in complete or mixed rations f0; different classes and weights of hogs. In formulating rations for complete mix tures, one can use enough high quality cottonseed a meal to furnish 25 percent of the crude protei~ for mixtures containing 15 to 16 percent crud protein. i High quality cottonseed meal can furnish percent of the crude protein for mixtures co taining 12 to 14 percent total crude protein whe y’ _ the cottonseed meal contains 0.04 percent or le of free gossypol. ‘ Thirty-seven to 40 pounds of cottonseed m :1 can be used in a 100-pound protein suppleme, mixture. This protein supplement mixture ca - then be mixed with ground grain to formula ’ the complete mixtures containing the percenta Growing and fattening hogs TABLE 16. RECOMMENDED PROTEIN CONTENT OF SWINE RATIONS Breeding stock Cllss weaned 10o to 20o to sows B°ars hogs m0 200 240 G t t. L t. B . Non. - d . 32s.?" 7.21%.‘? $2.129 1133339 f‘ ent crude protein feed mixture l5 l4 l2 ‘ l5 l5 l5 ‘ l4 l ee-choice Feedings h_ The free-choice method of feeding is practi- i and economical where one is feeding out hogs , market. ‘ Table 17 shows-two protein supplement mix- res containing cottonseed meal which are re- mmended for both free-choice feeding and rmulating complete mixtures. 3 After the pigs are 10 weeks old, they can be 1;» the protein supplement and grain free-choice f different compartments of a self-feeder. . Pigs intended for breeding should be taken q the free-choice method of feeding when they We 4 to 5 months old and be fed a complete mix- re twice daily by hand. The condition of the eeding animals can be controlled better by hand eeding during the development period of the nimal. __ Milo or corn with either protein supplement o. 1 or no. 2 may be fed free-choice in self-feed- s to growing-fattening pigs after the pigs have eached 40 pounds live weight, or after they are 0 weeks old. ,_ For brood sows, gilts and herd boars, one l.» use a mixture containing supplement no. 2 51.; follows: MIXTURE A Ground milo 63 pounds Wheat shorts 20 pounds Supplement no. 2 17 pounds Total 100 pounds Mixture A contains 15 percent crude protein a d 5 to 6 pounds of this mixture per sow daily aould give good results during the gestation riod. After farrowing and being brought to a aull feed gradually, sows with 8 pigs will require ’ to 12 pounds of the mixture daily per sow. freen pasture should be provided for brood sows ring the gestation and lactating periods and for erd boars: If the green pasture is excellent, mix- 5 p. re A can be changed to only 10 pounds of , pplement with 27 pounds of wheat shorts. This a nge should not be made, however, unless the asture is plentiful, green and tender. Mature ,sture or forage plants are of little use to swine. round oats may replace all or a part of the Wheat Shorts in mixture A. Where one would like a mixture for the brood sow or herd boar and would prefer supplement no. 1, the following 15 percent crude protein mixture may be used: MIXTURE B Ground milo 59 pounds Supplement no. 1 16 pounds Wheat shorts 15 pounds Ground oats 10 pounds Total 100 pounds This mixture B should be used where good green pasture is available for the breeding herd. Where no green pasture is available, mixture C 1s recommended. MIXTURE C Ground milo 53 pounds Supplement no. 1 14 pounds Wheat shorts 15 pounds Ground oats 10 pounds Green alfalfa meal 8 pounds Total 100 pounds If the sows have access to a good green forage crop, ‘mixture B may be changed to one containing 65 pounds of ground milo, 15 pounds of wheat shorts, 10 pounds of ground oats and 10 pounds of supplement no. 1. TABLE 17. USE OF COTTONSEED MEAL IN PROTEIN SUP- PLEMENTS FOR SWINE RATIONS Crude Number l‘ Number 2’ Ingredients protein. "/, Pounds Pounds Soybean meal 44 35 37 Cottonseed meal 41 2U 37 Meat scraps ' 50 20 Dehydrated alfalfa 1 leaf meal 20 1 20 l9 Ground limestone 2 4 Salt 1 1 Aurofaca 2 2 Total 100 100 ‘Percent of total crude protein is 37.60. ‘Percent of total crude protein is 35.25. “Containing 1.8 grams of aureomycin and, 1.8 grams of vita- min B12 per pound. 13 ACKNOWLEDGMENTS The authors are indebted to the Educational Service, National Cottonseed Products Associa- tion, Inc., Dallas, Texas for grants-in-aid; Buck- eye Cotton Oil Co., Memphis, Tennessee, for furnishing degossypolized cottonseed meal; South- ern Regional Research Laboratory, I). S. Depart- ment of Agriculture, for supplies of special pro- cesses of cottonseed meals; and to Otto P. Seeman, herdsman, for his efficient assistance in the feed- ing of the experimental animals. LITERATISIRE CITED Baliga, B. P. and C. M. Lyman. 1957. Prelimi- nary report on the nutritional significance of bound gossypol in cottonseed meal. J. Amer. Oil Chemists’ Soc. 34 :21. Bohstedt, G. and J. M. Fargo. 1933. Facts for farmers. Wis. Agr. Exp. Sta. Bul. 425. Cabell, C. A. and I. P. Earle. 1956. Relation of amount and quality of protein in the diet to free gossypol tolerance by the rat. J. Amer. Oil Chemists’ Soc. 33:416. Cannon, P. R., E. M. Humphreys, R. W. Wissler and L. E. Frazier. 1944. The effects of feed- ing possible blood substitutes on serum pro- tein regeneration and weight recovery in the hypoproteinemic rat. J. Clin. Invest. 23:601. Chang, Wan Yuin, J. R. Couch, Carl M. Lyman and others. 1955. The nutritional value of prepress-solvent cottonseed meals. J. Amer. Oil Chemists’ Soc. 32:103. Curtis, C. F. 1895. Feeding cottonseed and other meals to hogs. Iowa Agr. Exp. Sta. Bul. 28. Curtis, G. W. and J. W. Carson. 1892. Effect of cottonseed and cottonseed meal as foods for hogs. Tex. Exp. Sta. Bul. 21 Dinwiddie, R. R. 1903. Pig feeding experiments with cottonseed meal. Ark. Agr. Exp. Sta. Bul. 76. Earle, I. P. and J. W. Stevenson. 1957. Relation of quantity and quality of dietary protein to tolerance of the growing pig for free gossy- pol. Proceedings of Fourth Conference on Processing as Related to Nutritive Value of Cottonseed Meal. p. 66. " - Georgeson, M., F. C. Burtis and D. H. Otis. 1895. Feeding experiments with pigs on corn, 14 _, wheat, kafir corn, and cottonseed meal. K Agr. Exp. Bul. 53. - Hale, Fred. March, 1930. Cottonseed meal feed for hogs. Tex. Agr. Exp. Sta. Bul. 4? Hale, Fred and C. M. Lyman. 1957. Effect, protein level in the ration on gossypol to ance in greasing-fattening pigs. J. Ani '4 Sci. 16 x64. 1 Harris, W. D., F. F. Bishop, C. M. Lyman and} Helpert. 1947. Isopropanol as a solvent , extraction of cottonseed oil. J. Amer. Chemists’ Soc. 24:370. .- Hove, E. L., and H. R. Seibold. 1955. Li’ necrosis and altered fat composition in vi min E-deficient swine. J. Nutr. 56:173. l Kuilcen, K. A., W. H. Norman, C. M. Lyman f F. Hale. 1943. The microbiological dete nation of amino acids. Sci. 98:266. Also; Biol. Chem. 151 :615. ’ Lathrop, A. W. and G. Bohstedt. 1938. Oat i. feed—its usefulness and value in livest rations. Wis. Agr. Exp. Sta. Bul. 135. i Lyman, C. M. and B. P. Baliga. 1958. React" of proteins with gossypol. Arch. Bioc '_ and Biophys. In- press. Lyman, C. M., W. Y. Chang and J. R. Co 1953. Evaluation of protein quality in { tonseed meals by chick growth and by‘. chemical index method. J. Nutr. 49:679. Lyman, C. M., B. R. Holland and F. Hale. 19 Determination of free gossypol in cottons meal, a colorimetric method. Ind. and Ef Chem. Anal. Ed. 15:489. I Lyman, C. M., B. R. Holland and F. Hale. 19 Processing cottonseed meal, a manufactu method for eliminating toxic qualities. and Eng. Chem. Anal. Ed. 36:188. l Obel, A. L. 1953. Studies on the morphology a; etiology of so-called toxic liverdystr I, (hepatosis diaetetica) in swine. Acta Pa et Microbiol. Scandinav. Suppl. 94, 87 pp. Robison, W. L. 1934. Cottonseed meal for p' Ohio Agr. Exp. Sta. Bul. 543. ' Smith, Hilton A. 1957. The pathology of gossy poisoning. Am. Path. 33:353. West, J. L. 1940. Lesions of gossypol poisoni in the dog. J. Am. Vet. M. A. 69:74. i [Blank Page in Griginal Bulletin] w: v. Location oi field research units oi the Texas Agricultural Experiment Station and cooperating agencies CRGANIZATION OPERATIQN Research results are carried to Texas farmers, ranchmen and homemakers by county agents and specialists of the Texas Agricultural Ex- tension Service jotlay 2 Western/t .95 jomorrow 2 regress . administrative staff. Located out in the major agricultural areas of Texas; State-wide Research iii‘? "k The Texas AgriculturalExperiment Stationgf; is the public agricultural research agency oi the State oi Texas. and is one oi ten if parts oi the Texas A8=M College System A IN THE MAIN STATION, with headquarters at College Station, are 16 subj_ matter departments, 2 service departments, 3 regulatory services and 21 substations and 9 field laboratories. ln addition, there are 14 coopertif stations owned by other agencies. Cooperating agencies include the Te ForestService, Game and Fish Commission of Texas, Texas Prison Syst U. S. Department of Agriculture, University of Texas, Texas Technolo" College, Texas College of Arts and Industries and the King Ranch. Sol experiments are conducted on farms and ranches and in rural homes. if; THE TEXAS STATION is conducting about 4-00 active research projects, grou in 25 programs, which include all phases of agriculture in Texas. A t " these are: Conservation and improvement of soil Beef cattle Conservation and use of water Dairy cattle ,_ Grasses and legumes Sheep and goats Grain crops Swine Cotton and other fiber crops Chickens and turkeys Vegetable crops Animal diseases and parasites p Citrus and other subtropical fruits Fish and game Fruits and nuts Oil seed crops Ornamental plants Brush and weeds Insects Farm and ranch engineering Farm and ranch business V. Marketing agricultural products Rural home economics Rural agricultural economics Plant diseases Two additional programs are maintenance and upkeep, and centralsservif AGRICULTURAL RESEARCH seeks the WHATS. the WHYS. the WHENS. the WHERES and the HOWS oi hundreds oi problems which confront operators oi iarms and ranches. and.» the many industries depending on or serving agriculture. Workers oi the Main Station and the iield units oi the Texas Agricultural Experiment Station seek diligently to iind solutions to these problems.