Cottonseed Meal Diet Research Articles

The effect of gossypol in cottonseed meal on performance and on hematological and semen traits in postpubertal Brahman bulls

The effects of a cottonseed meal diet containing high levels of free gossypol on hematological traits, including erythrocyte osmotic fragility and semen characteristics, were examined during an 11-week period. Eight Brahman bulls were randomly assigned to 1 of 2 groups. The control group (n=4) was fed a mixture of soybean meal and corn. The treated group (n=4) was fed a mixture of cottonseed meal and corn. Both groups were allowed hay free choice. The treated group consumed 8.2 g of free gossypol per bull per day. The percentage of normal spermatozoa was lower (P<0.01) in the treated than in the control group from Week 5 (49±9.8 vs 83±3.2%), which was primarily influenced by changes in mid piece morphology in the treated bulls. Erythrocyte osmotic fragility was higher (P<0.001) in the treated than in the control group over the entire study period, although group values diverged more acutely from Week 7 of treatment. Sperm motility was lower (P=0.04) in treated bulls than in control bulls at Week 9 (52±9.8 vs 82±6.2%). These data suggest that concurrent discernable changes in bull erythrocyte osmotic fragility and in semen characteristics can occur following commencement of a diet containing 8.2g of free gossypol per day.

Effects of dietary cottonseed meal and iron‐treated cottonseed meal in different laying hen genotypes

The effects of dietary screw-pressed cottonseed meal (CSM) and iron-treated CSM on laying performance and discolourations in eggs were examined in a range of hen genotypes. In experiment 1, six genotypes, obtained at point-of-lay from various sources, were fed on a non-CSM diet, a diet with 300 g CSM/kg, and a diet containing iron-treated CSM at 300 g/kg. In experiment 2, two of these genotypes were reared together from day-old and were fed from 10 to 18 weeks on a non-CSM diet or a diet containing iron-treated CSM at 250 g/kg. They were then fed on a non-CSM layer diet or a diet containing iron-treated CSM at 300 g/kg, in a 2 x 2 x 2 factorial design that also examined the effects of the rearing diet. 2. The effects on food intakes and egg production of including CSM and iron-treated CSM in layer diets depended on the genotype of the hens. The strongest interaction between breed and diet was on food intake, the breed Hubbard Golden Comet (HGC) being the least tolerant of CSM and iron-treated CSM. 3. Inclusion of iron-treated CSM in the rearer diet to supply approximately 70% of the dietary protein had no adverse effects on growth or age at first egg. Food intake and egg production between 18 and 26 weeks were affected by the iron-treated CSM layer diet, but there were no carry-over effects attributable to the rearing diets. 4. Genotype was not a factor in the development of the gossypol-related brown yolk discolouration in fresh or warm-stored eggs of hens fed on a CSM-based diet containing 197 mg free gossypol/kg and 52 mg cyclopropenoid fatty acids (CPFA)/kg (experiment 1). 5. In both experiments, the susceptibility of eggs to the CPFA-related cold storage effects depended on the genotype of the hen, eggs from hens of the HCG breed being more affected than those of ISA hens. 6. Treatment of CSM with crystalline ferrous sulphate heptahydrate, at a 4:1 weight ratio of iron to free gossypol, prevented brown yolk discolourations in all genotypes tested, as assessed by subjecting egg yolks to atmospheres of ammonia, and cold storage of eggs.

Effects of dietary cottonseed meal, with and without iron treatment, on laying hens.

1. The effects of feeding a screw-press expelled cottonseed meal (CSM) to laying hens at dietary concentrations of up to 300 g/kg, were studied over a 10 week period. 2. The overall performance of hens fed on a 75g CSM/kg diet was not significantly different from controls but a 300g CSM/kg diet, containing 255 mg free gossypol/kg and 87 mg cyclopropenoid fatty acids (CPFA)/kg and giving daily intakes per hen of 26.2 mg free gossypol and 9.0 mg CPFA, significantly reduced food intake (P less than 0.01) and egg production (P less than 0.01). The 150g CSM/kg diet (daily intakes of 14.6 mg free gossypol and 4.8 mg CPFA per hen) did not produce adverse effects initially but egg production was slightly depressed towards the end of the experimental period. 3. Treatment of the CSM with a solution of ferrous sulphate hepta-hydrate for inclusion in a 300g CSM/kg diet (100 mg/kg supplemental dietary iron) further reduced food intake (P less than 0.05) and egg production (P less than 0.05). 4. Storage of eggs at warm temperatures for up to 1 month did not lead to discolourations of any kind in the CSM diet groups, but resulted in yolk mottling, a condition reduced by treatment of the CSM with iron. 5. Storage of eggs at cold temperatures for 3 months resulted in brown yolk discolouration and the initial stages of pink albumen discolouration in the 300g CSM/kg diet group; the brown yolk discolouration was reduced by treatment of the CSM with iron.

Digestibility of threonine from protein concentrates for growing pigs. 1. The flow of endogenous amino acids to the terminal ileum of growing pigs

Six pigs (25 kg initial weight) were fitted with T cannulas in the terminal ileum. Each pig was fed a nitrogen (N) free diet or one of eight diets containing increasing amounts of threonine from milk (four diets) or cottonseed meal (four diets). The flow of endogenous nitrogen from the terminal ileum was 1.1 g/kg dry matter DM intake in the pigs given the nitrogen-free diet and 0.9 g/kg DM intake when estimated by extrapolation in the pigs given the milk or cottonseed meal diet. There were no significant differences in the flow of individual endogenous amino acids from the terminal ileum when measured in pigs given a nitrogen-free diet or when extrapolated from data for pigs given diets containing milk or cottonseed meal. The flow of endogenous threonine from the terminal ileum was between 0.39 and 0.45 g/kg DM intake as estimated in pigs given diets with similar threonine intakes from cottonseed meal or milk and the nitrogen-free diet.

Equi‐protein substitution of cottonseed meal for groundnut cake in diets for weaner‐grower pigs

AbstractNigerian processed cottonseed meal was substituted for 0, 25, 50, 75 and 100 % portions of dietary groundnut cake on an equi‐protein basis. The diets were fed to 50 Large White and Large White × Landrace crossbed pigs from 13.9 kg average weight to 70 kg liveweight in a bi‐replicate single‐way classification trial. Average daily gain and average daily feed consumption were 0.51, 0.52, 0.53, 0.55 and 0.56 kg; and 1.67, 1.77, 1.85, 1.84 and 1.82 kg for the respective diets. Feed/gain ratios ranged from 3.25 to 3.49. No significant differences between diets were seen for either of these parameters. Neither the gross tissue nor the jointed carcass proportions were significantly affected by cottonseed meal substitutions. The mean fresh weights of the liver and lungs decreased with increasing levels of dietary cottonseed meal but the differences were not significant. None of the pigs showed symptoms of gossypol intoxication. The data suggest that some of the Nigerian‐processed cottonseed meals can be combined in various proportions with groundnut cake to supply protein, or used singly, up to 20 %, in diets for weaner‐grower pigs.

Fish Meal or Cottonseed Meal as Supplemental Protein for Growing Holstein Steers

Twenty-three Holstein steers of 195kg mean live weight were individually fed a complete mixed diet composed primarily of ground corn grain with either 140g cottonseed meal or 90g cottonseed meal plus 30g menhaden fish meal/kg diet as the source of supplemental protein. Thirteen steers were slaughtered at 454kg and 10 at 544kg live weight. Steers slaughtered at 544kg gained weight more slowly with consequent 18.2% increase in dry matter required per unit gain compared with steers slaughtered at 454kg live weight. Steers fed the fish meal diet gained 1.34 kg/d and consumed 7.36kg dry matter daily while steers fed the cottonseed meal diet gained 1.17 kg/d and consumed 7.40kg dry matter daily. Dry matter consumed per unit gain was 12.6% less for steers fed fish meal diet than for steers fed cottonseed meal diet.

Lactic dehydrogenase activity in various organs of rats fed cottonseed flour

Male rats fed cottonseed meal diet or protein-free diet for four weeks showed a decreased lactic dehydrogenase (LDH) activity in the liver, heart and testicle, but not in skeletal muscle. At the end of this treatment, the animals were fed with Purina Chow control diet for 14 weeks of recovery. After ten weeks of recovery, the animals fed cottonseed meal showed normal LDH values for the testicle and heart. In the liver, the low value remained so during the 14 weeks of recovery. Normal values were reached in the animals fed protein-free diet at six weeks of recovery. The decreased LDH activity in animals fed cottonseed diet may be due to the gossypol present in it.

Effect of lasalocid on growth and puberal development in Brahman bulls.

Twenty-four half-sib Brahman bulls (171 to 276 d of age; 140.9 to 243.2 kg) were paired by age and weight and randomly allotted to one of two treatment groups (12 bulls/treatment) with two replicates (six bulls/replicate). Control treatment (C) was a 4:1 corn (IFN 4-02-931):cotton-seed meal (IFN 3-01-621) diet fed at 1% of the average body weight plus Coastal bermudagrass hay (IFN 1-00-716) ad libitum. Lasalocid treatment (L) was the control diet with the addition of 200 mg lasalocid X head-1 X d-1. Lasalocid resulted in lower acetate and butyrate with higher propionate and no change in total ruminal volatile fatty acids. Lasalocid-fed bulls tended to gain more weight (L = 153.6 +/- 8.5 kg, C = 138.4 +/- 7.9 kg; P less than .08), tended to have a greater average daily gain (ADG; L = .78 +/- .05 kg/d, C = .71 +/- .04 kg/d; P less than .09) and had greater feed conversion (11.5% less feed/kg gain) than did the control bulls. Lasalocid did not affect bull height (HT), weight:height ratio, length (LE) or heart girth (HG) at any time tested during puberal development. Lasalocid bulls exhibited a greater increase in HG through 175 d on treatment (L = 27.6 +/- 1.0 cm, C = 24.3 +/- 1.8 cm; P less than .05) and through first detected sperm (FS) in an ejaculate (L = 30.1 +/- 2.2 cm, C = 26.1 +/- 1.4 cm; P less than .05), but the increase in HG from the start of the trial through puberty was not different between treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Urea Levels and Supplemental Energy Sources in Sugarcane Diets

Two experiments, each involving a digestion-N balance trial and a feedlot trial, determined the replacement value of urea-corn meal (UC) for cottonseed meal (CSM) and the value of molasses in sugarcane diets. Steers fed 70% sugarcane-30% concentrate diets with 0, 28 or 56% of the dietary N as urea had a slight reduction (P<.28) in dry matter (DM) intake and an increase (P<.01) in crude protein digestibility as dietary urea increased. Urea level did not affect the digestibility of other dietary components. Urea N appeared to be utilized less efficiently than CSM N. In the feedlot, steers were fed 71% sugarcane-29% concentrate diets with 0, 25 or 50% of the dietary N as urea during a 93-d growing phase, then 39.5% sugarcane-60.5% concentrate diets with 0, 20 or 40% of the dietary N as urea, respectively, during a 63-d finishing phase. Growing steers fed urea gained slower (P<.01), consumed less DM and required more DM/kg of gain (P<.05). Dietary urea level did not affect gain, DM intake or DM utilization during finishing, nor did it affect carcass quality. Steers fed 70% sugarcane-30% concentrate diets, with urea and CSM as N supplements and molasses and corn as energy supplements to the high-urea diet, had higher DM digestibility (P<.01) for the urea-molasses (UM) supplemented diet than for the CSM diet. Digestibilities of all components of the UM and UC diets were similar. Retention of N was similar for steers fed the UC and CSM diets, but both groups retained more N than steers fed the UM diet. In the feedlot, steers fed the UM diet gained slower (P<.01) with lower efficiency than steers fed the CSM or UC diets. Performance of steers fed CSM or UC diets was similar. This study showed that urea was inferior to CSM as a crude protein source in sugarcane diets, especially when molasses was used as an energy supplement.

EVALUATION OF LIQUEFIED FISH IN DIGESTIBILITY AND FEEDLOT PERFORMANCE STUDIES WITH SHEEP

Liquefied fish (LF) prepared from whole Pacific whiting (Merluccius productus) containing about 25% dry matter (DM) and 56% crude protein (CP; dry basis) was evaluated as a supplemental protein source. LF contained a well-balanced amino acid profile. The LF product appeared to be stable when stored under ambient conditions. Two digestion trials were conducted with 20 yearling wethers. Treatments consisted of diets in which grass hay was fed with liquid supplements (LS) in which graded amounts of LF replaced urea. The LF replaced 0–15% (trial I) or 0–7.5% (trial II) of the CP from urea in the LS. In trial I, digestibility of CP was increased (P &lt; 0.10), as was acid detergent fiber (ADF; P &lt; 0.05) and gross energy (GE; P &lt; 0.01) as the LF level increased. Nitrogen retention (NR) was also improved (P &lt; 0.05), as was the biological value (P &lt; 0.05), with the addition of LF. In trial II, digestion coefficients were increased (P &lt; 0.05) for DM, organic matter, ADF and GE, as were NR and biological value, as the level of LF increased. A feedlot trial was conducted in which lambs were fed pelleted diets formulated to contain no supplemental CP, or supplemental CP supplied by cotton seed meal (CSM), urea or urea plus LF. After being fed for 43 days, lambs were slaughtered, carcass data were collected and taste panel evaluation was performed on the roasted longissimus muscles. Results of the trial showed that there were no differences in daily gain, total feed intake, feed efficiency, yield and quality carcass grades among the lambs fed these diets (P &gt; 0.10). The dressing percentage was higher for lambs fed LF compared with the CSM and control diets (P &lt; 0.10). There were no differences in organoleptic evaluation of cooked roasts for tenderness, flavor or overall desirability (P &gt; 0.05), but CSM increased meat juiciness over urea + LF (P &lt; 0.05, and urea decreased the aroma score as compared with the control diet (P &lt; 0.05). Data obtained indicate that LF could be used as a source of supplemental CP for sheep. Key words: Liquefied fish, sheep, digestibility, liquid supplements, finishing sheep, alternative protein source

Value of mechanically extracted rape and safflower oilseed meals as protein supplements for growing lambs

Two metabolism studies and one growth trial were conducted to evaluate mechanically extracted rape (RSM) and safflower (SM) oilseed meals as protein supplements for growing lambs. Fifteen wether lambs were allotted randomly to one of five treatment groups in each metabolism study. In both studies, treatments consisted of a cottonseed meal (CSM) positive control, a urea (U) negative control and three test diets in which RSM or SM replaced 33, 66 or 100% (RSM) or 25, 50 and 75% (SM) of the CSM protein. In the growth trial, 72 ewe lambs (initial weight, 29 kg) were randomly allotted to one of four dietary treatments in which U, SM and RSM replaced all the CSM protein in a pelleted 14.0% crude protein diet. In both metabolism studies, the RSM and SM diets had significantly higher ether extract digestibility than the CSM diets. In the first trial, lambs fed on the U diet retained less ( P<0.05) absorbed N than those fed on the CSM diet. However, in the second trial, there was no difference in N balance between treatment groups. In fact, the U pellet in the second metabolism study had a higher dry matter and gross energy digestibility than the CSM or SM pellets. Lambs fed on the CSM, U and SM pellets grew significantly faster than those fed on the RSM pellets. Lambs fed on the U pellets consumed significantly more dry matter than those fed on CSM or RSM pellets. These results suggest that U, CSM and mechanically extracted SM in a high-grain pellet are satisfactory sources of supplemental N for growing—finishing ewe lambs. It appears that the high glucosinolate concentration of RSM limits the amount that can be included in diets given to growing—finishing ewe lambs.

Effects of Dietary Cottonseed Meal and Gossypol on Growth of Young Channel Catfish

Abstract Ten isonitrogenous and isocaloric diets containing different percentages by weight of cottonseed ineal or gossypol acetate were fed to age-0 channel catfish Ictalurus punctatus for 8 weeks. Growth was inhibited when fish were fed diets with more than 17.4% cottonseed meal or with 0.09% and greater free gossypol. Fish fed cottonseed meal at 17.4% or greater had higher wholebody concentrations of free gossypol than fish fed lower amounts. Free gossypol in muscle tissue was less than that recommended as safe for human consumption. Free gossypol was most concentrated in liver and kidney tissue. Channel catfish utilized lysine hydrochloride when a diet was supplemented with that amino acid.

Effects of Diet Composition on Vanadium Toxicity in Laying Hens

Vanadium added to laying rations as NH4 VO3, VOCl2 or VOSO4 at levels of 20 to 80 ppm resulted in a rapid and substantial reduction in albumen quality as measured b y Haugh units. Dietary vanadium also resulted in reduced egg production, egg weight, body weight, feed consumption, and poorer shell quality as measured by specific gravity. Ascorbic acid at .4 t o .5% effectively protected the hen from the reduction in albumen quality, egg production, and body weight for up to 40 ppm vanadium, but not the reduction of egg weight Replacement of soybean meal by 20% dietary cottonseed meal also protected the hen from the reduction in albumen quality, egg production, and body weight for up to 40 ppm vanadium.Added at levels of 4 to 8 times the molecular concentration of vanadium, EDTA had no consistent effect on vanadium toxicity. Dehydrated grass, at levels of 6 to 12%, maintained egg production but had no effects on the reduction in albumen quality caused by 40 ppm vanadium. Replacement of soybean meal with herring fish meal and part of the grain with sucrose intensified the depression of albumen quality, egg production, and loss of body weight caused by added vanadium. Neither varying dietary protein levels from 12 to 25% using soybean meal nor the addition of 20 ppm chromium had any effect on the toxicity of added vanadium.It appears that vanadium expresses its toxicity in laying hens by several routes since the protective effects of different dietary changes and additives differentially affected the loss of albumen quality, egg production, body weight, and egg weight.

Effect of Lysine, Crude Fiber and Free Gossypol in Cottonseed Meal on the Performance of Growing Pigs

Two factorial designed individual pig feeding trials and a digestion trial were conducted to delineate the effect of lysine, crude fiber and free gossypol in cottonseed meal (CSM) on the performance of growing pigs fed sorghum-CSM diets. Trial 1 examined three levels of lysine (.60, .70, .80%), two levels of fiber (3.0, 4.5%) and three levels of free gossypol (90, 300, 500 ppm) using specially processed CSM's while Trial II examined the same levels of dietary lysine and two levels of fiber (2.58, 3.54%) using a commercial direct solvent cottonseed meal. Supplemental iron was added to all CSM diets to give a 1:1 weight ratio of iron:free gossypol. The effect of dietary fiber levels in Trial II on energy and protein digestibility was investigated in Trial III. In Trial I, increasing the dietary lysine level gave a quadratic improvement in gains (P<.05) and feed intake (P<.10) and a linear improvement in feed efficiency (P<.05). Crude fiber level had minimal effect on feed intake and gain, but pigs fed the low fiber diet had more desirable feed to gain ratios (P<.05). Dietary free gossypol level did not significantly affect any production trait (P>.10). Increasing dietary lysine levels in Trial II caused a linear increase in feed intake (P<.05), gains and feed efficiency (P<.01). Performance indicated that lysine availability was much lower in the commercial direct solvent than the special processed cottonseed meals. Crude fiber level had little effect (P>.10) on pig performance. In Trial III, the low fiber diet exhibited higher dry matter and gross energy digestibilities (P<.05) than the high fiber diet. These data suggest that the lowered performance of growing pigs fed sorghum-CSM diets is due primarily to low dietary lysine. Dietary crude fiber affected only feed utilization while dietary free gossypol had no effect on pig performance when iron was included in the diets on a 1:1 weight ratio to free gossypol.

Nitrogen Utilization by Lambs Fed Wheat Straw Alone or with Supplements Containing Dried Poultry Waste, Cottonseed Meal or Area2

Three male lambs were used in a 3 x 3 latin square to determine utilization of N from diets containing wheat straw supplement with dried poultry waste (DPW) cottonseed meal (CSM), or urea. Supplements formulated from the three N sources provided 85% of the total dietary N. The DPW and CSM provided over 90% and urea over 70% of the N in their respective supplements. Daily intakes of total dry matterl straw dry matter, and N were not affected by the source of the supplemental N. Apparent digestibility of N was higher for the urea-supplemented diet (74%) than for DPW (68%) or CSM (67%) diets. Daily urinary N excretion was highest on the urea diet. (16 g) followed by DPW (14 g) and CSM (11 g) diets. Approx. 35% of the absorbed N was retained on the CSM diet compared with 16% for DPW and urea diets. Upon completion of the latin square, the lambs were fed only wheat straw for 70 days. N balances were determined after 10, 28, and 63 days. Daily intakes of straw dry matter and N were similar for all 3 collection periods. Although the lambs were in negative N balance throughout this unsupplemented phase,more » the degree of negativity decreased in each succeeding collection period.« less

A Comparison of Cottonseed Meal, Alfalfa Meal, and Hominy Feed Diets for Rearing the Cabbage Looper 1, 3,4

Cabbage loopers, Trichoplusia ni (Hubner), reared on a low-agar cottonseed meal diet developed faster, yielded more larvae, produced more normal moths, and oviposited more eggs than cabbage loopers reared on an alfalfa meal diet or a low-agar hominy feed diet. Also, egg viability was significantly higher when females were reared on cottonseed meal and hominy feed diets than when they were reared on alfalfa meal diet. The lesser amounts of agar used in the cottonseed meal and hominy feed diets, the elimination of several ingredients (KOH, alphacel, choline chloride, and ethanol), and the low-cost nutritive base ingredients (cottonseed meal and hominy feed) reduce production costs compared with the alfalfa meal diet.

Lysine Requirement of White Leghorn Pullets From 8 to 21 Weeks of Age

White Leghorn pullets were fed rations in which the protein supplementary to that provided by the grain portion of the ration was derived from soybean meal, meat and bone meal, anchovy fish meal or cottonseed meal from 8 to 21 weeks of age. Protein levels were varied so that each protein supplement was tested in a feeding program in which pullets received 16% protein diets from 8 to 14 weeks and 14% protein from 14 to 21 weeks and in another feeding program in which 14% protein was fed from 8 to 14 weeks and 12% protein from 14 to 21 weeks.Each of the developing rations contained sufficient nutrients to enable pullets to develop and attain high rate of laying performance. The 14% and 12% protein cottonseed meal diets contained only 0.50% and 0.45% lysine respectively. Thus the lysine requirement of White Leghorn pullets from 8 to 14 weeks and from 14 to 21 weeks is not over 0.50% and 0.45% respectively.

Cottonseed meal in broiler diets. 2. Considerations of some aspects of amino acid balance and gossypol level in cottonseed meal and cottonseed-meat meal starter diets

Three broiler starter experiments investigated the inclusion of cottonseed meal in diets based on grain sorghum. In the first, 35.5 per cent cottonseed meal inclusion in lieu of 28.5 per cent soyabean meal was studied. Additional 0.05 per cent ferrous sulphate, to counteract gossypol toxicity in the cottonseed diets, increased feed consumption by 4.3 per cent and improved liveweight gain by 2.2 per cent. Dietary leucine at 1.25 per cent tended to give better performance than either 1 .I 5 or 1.35 per cent. No differences in performance occurred with isoleucine levels of 0.54 - 0.74 per cent. On the better cottonseed diets growth rate equalled that on the soya controls, though feed conversion was inferior. In the second experiment meat meal protein replaced 0, 25 or 50 per cent of the cottonseed meal protein. Growth was optimal on the cottonseed meal diet with 1.35 - 1.45 per cent total dietary lysine. On the meat meal-cottonseed meal diets, lysine levels of between 1.10 - 1.45 gave no significant differences in growth rate or feed efficiency. Leucine supplementation in addition to lysine did not affect performance. Overall, the diets with one-half meat meal protein substitution for cottonseed meal protein resulted in significantly depressed growth. In the third experiment, half the cottonseed protein was replaced by either a 'normal' meat meal or a meat meal containing blood. The cottonseed meal-normal meat meal diet was shown to be equally deficient in leucine and isoleucine, whereas the cottonseed meal-meat meal with blood diet was deficient in isoleucine only. With adequate amino acid supplementation, the performance on these cottonseed meal-meat meal diets was not inferior to that of a control diet based on soyabean meal.

Winter Survival of the Boll Weevil in the High and Rolling Plains of Texas12

Cage studies of the overwintering ability of Anthonomus grandis Boheman showed that higher percentages of individuals reared on cotton bolls survived the winter than did individuals reared on squares or a cottonseed meal diet, or adults collected from the field. The time during the fall that boll weevils were placed into over-wintering cages did not affect the time of emergence in the spring. However, boll weevils installed in cages between Oct. 15 and Nov. 3 had higher survival rates than weevils installed earlier or later. Peak boll weevil emergence occurred in mid-May.

Locally produced cottonseed meal for growing pigs

The nutritive value of locally produced cottonseed meal, incorporated at a level of 10 per cent in wheat based diets, was compared with meat and bone meal and soybean meal for growing pigs. The effect of adding synthetic lysine to the cottonseed meal diet was also observed. The diets were fed at restricted rates and pig performance was assessed over the 18 to 45 kg, 45 to 73 kg, and 18 to 73 kg growth phases. Cottonseed meal was of similar nutritive value to meat and bone meal and the addition of lysine increased growth and feed conversion during the 18 to 45 kg growth phase. Soybean meal produced similar gains to the cottonseed meal plus lysine diet during the 18 to 45 kg range, but greater gains than the other three diets over the 18 to 73 kg range. Carcase quality was similar for all four diets. With cottonseed meal there was an increase in the ratio of saturated to unsaturated fatty acids in the backfat of the pigs due to cyclopropene fatty acids in the residual oil in the meal. The metabolizable energy values of the diets were approximately 96.7 per cent of the digestible energy values and there was a significant correlation between them (r = 0.94). The correlation between digestible energy values estimated by the methods (gross energy in the feed X dry matter digestibility) and (gross energy in feed - gross energy in faeces/dry matter intake) was significant (r = 0.92).