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Experiments were designed to investigate the effect of feeding diets deficient in one or more of the three branched-chain amino acids (BCAA) on the performance of 3-wk-old male broilers. In the first experiment, levels of .96 and 1.46% Leu, .52 and .82% Ile, and .65 and .95% Val were used. Feeding the lowest combination of the three BCAA resulted in weight gain (WG) and feed conversion ratio (FC) of 344 g and 1.59 g:g, respectively. These parameters were not improved by adding dietary increments of the three BCAA individually. The greatest response, however, for both WG (435 g) and FC (1.41 g:g) was obtained by the addition of the three BCAA simultaneously. Chicks fed the low-Val diets in combinations with added levels of Ile and Leu exhibited feather and leg abnormalities. A second experiment was designed to investigate the effect of Val deficiency on feather protein, feather amino acids, and calcium content of the bone. Three treatments were used: a BCAA-deficient diet with .96% Leu, .52% Ile, and .63% Val; a Val-deficient diet, which contained 1.37, .82, and .63% of Leu, Ile, and Val, respectively; and a Val-supplemented diet, which was the same as the previous diets except that the Val content was .83%. Valine deficiency significantly decreased WG (243 g), FC (1.69 g:g), bone calcium (134 mg/g dry bone), and feather protein (82.7% of wet weight). Valine deficiency also decreased the level of Cys in feathers, but increased those of Asp, Glu, Met, Tyr, His, and Lys.(ABSTRACT TRUNCATED AT 250 WORDS)

Two experiments were conducted to determine the bioefficacy of methionine hydroxy analog free acid (MHA-FA) using the nonlinear (exponential) bioassay method. Male broiler chicks were fed a low methionine diet composed primarily of ground yellow corn and soybean meal for the 1st wk. The experimental diets, which varied in eight levels of DL-methionine and in eight equimolar levels of MHA-FA, were fed from 7 to 21 days of age. The source of protein was soybean meal and isolated soybean meal (15% of each) in the first experiment and soybean meal and peanut meal (23 and 21%, respectively) in the second experiment with glucose as the primary source of energy. Compared with DL-methionine on an equimolar basis, the bioefficacy of the MHA-FA was 72 ± 5 and 73 ± 7% using weight gains and feed conversions, respectively, from the first experiment and 85 ± 11 and 79 ± 8% using weight gain and feed conversion from the second experiment. These results clearly show that DL-methionine is much superior to MHA-FA on an equimolar basis.

Growth studies were conducted with 3-wk-old, male broiler chicks to determine their requirements for the branched-chain amino acids (BCAA) leucine, isoleucine, and valine during the starter period. The central-composite, rotatable design was applied. The data were analyzed using regression methodology. The results showed that the linear term of Leu and the cross-product terms of Leu with Ile or Val were nonsignificant (P greater than .05). Second-order equations described the relationship between the BCAA, weight gain (WG), and feed conversion (FC). The coefficient of determination values indicated that 80% or more of the variation in WG and FC was explained by the polynomial equations. The results suggested that the Leu requirement does not exceed 1.16% of a diet calculated to contain 3,200 kcal of metabolizable energy per kilogram. The optimum response, maximum in the case of WG (444 g) and minimum for FC (1.40), would be obtained by feeding a diet containing 1.16, .80, and .90% of Leu, Ile, and Val, respectively. The values of Ile and Val are the actual values obtained when the diets were hydrolyzed for 72 hours. For Leu, however, the hydrolysis time was 24 hours.

Two experiments were conducted to study the effect of feeding raw or treated common vetch seeds (V) on BW, feed intake (FI), egg production (EP), feed conversion (FC), egg weight (EW), shell thickness (ST), yolk color score (YC), and Haugh unit score (HU) of Single Comb White Leghorn hens for 56 d. In Experiment 1, diets contained 0, 7.5, 15, and 22.5% raw V. Compared with the control, the 22.5% V diet decreased (P < .05) BW, FI, and EP. In Experiment 2, intact or ground (G) V were either soaked (S) in water (1:5) for 24 h or autoclaved (A) at 103.5 x 10(3) Pa for 8 h, and then dried (D) at 55 C for 24 h. Eight diets were used, a corn soybean (control) and seven others, each containing 25% V, previously subjected to the forementioned treatments as follows: untreated V (UV), SDV, GSDV, ADV, GADV, SADV, and GSADV. Compared with the control, the UV diet decreased (P < .05) FI (75 vs 98 g) and EP (47.3 vs 88.7%), increased FC (1.99 vs 1.4 kg feed per dozen eggs), and induced BW loss (-63 vs 49 g). Soaking intact V improved (P < .05) FI (85 g) and EP (69%). Remaining treatments resulted in further improvement. Hens fed all V diets produced eggs with HU score 13 points better than that of the control (P < .05). In both experiments, EW, YC, and ST were not different among treatments. Results indicated that autoclaved V at 25% level was not detrimental to layers' performance.

Broiler breeders display high levels of aggressive activity as a result of feed restriction. The objective of this study was to determine if aggressive activity in developing and mature broiler breeder males is influenced by increased dietary L-tryptophan (Trp). Broiler breeder males were raised using a skip-a-day feed restriction regimen. In Experiment 1, three levels of dietary Trp, .19 (control), .75, and 1.5%, were fed from the start of feed restriction at 4 wk of age and throughout development. All occurrences of aggressive behavior were recorded during three 20-min observation sessions per week on mornings on which feed was not delivered through Week 20. The Trp significantly decreased (P less than .05) aggressive pecking in birds fed supplemental Trp as compared to controls. No differences in threatening behavior were found. In the second part of Experiment 1, the effect of continued Trp supplementation on mature flocks of male broiler breeders and time-of-day effects on aggression were investigated. A depressing effect of supplemental Trp on pecking and threatening was observed. Maximum aggressive activity in all treatment groups occurred on mornings when feed was delivered. In Experiment 2, four levels of Trp, .19 (control), .38, .75, and 1.5%, were fed to developing birds as in Experiment 1. Birds fed supplemental Trp pecked less (P less than .05) than controls and .38% Trp was as effective in decreasing pecking as was 1.5%. It was concluded that increased levels of dietary Trp decrease aggression in both developing and mature, socially stable flocks of broiler breeder males.

BAY Vi7533 (2-chloro-N-[[[4-(trifluoromethoxy)phenyl] amino] carbonyl] benzamide) was fed to White Leghorn and Vedette Mini-broiler breeder hens at concentrations ranging from 0 to 25 ppm in the ration. Concentrations of 15 and 25 ppm resulted in greater than 95% mortality of house flies, Musca domestica L., seeded as larvae into the droppings. Concentration of 25 ppm reduced egg production in the White Leghorn but not in the Vedette Mini-broiler hens. At each concentration (except 5 ppm for Vedette Mini-broilers) residues of the compound were detected in the eggs. These residues, however, had no adverse effects on fertility or hatchability of the eggs.

Day-old Arbor Acre male broiler chicks were fed 55%-rye diets with or without antibiotic supplements in three 14-day experiments. Procaine penicillin, chlortetracycline, or bacitracin methylene disalycilate were added individually to the rye basal diet at a concentration of 55 p.p.m. Weight gain and feed consumption were calculated at two-day intervals in all experiments. Chicks fed the antibiotic supplemented diets grew better than chicks on the basal diet. In each experiment chicks fed the unsupplemented diet gained weight at a linear rate for about the first eight days and exponentially thereafter. Feed conversion ratios (feed/gain) for chicks on the basal diet, calculated for each two-day interval, increased rapidly reaching a peak after eight days on the diet. Thereafter, the feed conversion ratios of the chicks on the unsupplemented diet declined until the 13—14 day interval when the experiments were terminated. All chicks exhibited a sticky feces condition regardless of the presence of antibiotics in their diet. It is concluded that young chicks adapt to diets containing rye. The adaptive response in these experiments occurred after the chicks had been on the diet for about eight days. Since the adaptation occurred only in chicks fed the unsupplemented diets, it is suggested that the adaptation is due to a change in the gut bacterial population.

Two studies were conducted in floor pen facilities to evaluate broiler diets containing various protein and amino acid levels. In Study #1 at 48 and 56 and at 49 and 59 days of age in Study #2, the number of body and flight feathers onthe litter in two separate 0.37 sq. meter areas located in the same place in each pen was recorded. In Study #1 Hubbard × Hubbard broiler crosses were employed. There were very few body feathers on the litter at 48 or 56 days of age. At 56 days the birds that had been on a high protein finisher ration had significantly (P

Data for individual feed intake, liveweight, and egg production were recorded for five genetically different groups of 40 pullets each during 10 test periods of 28-days each. Average ambient temperature at cage level varied from 6.7 C during January to 21.1 C during June. A 2890 kcal/kg metabolizable energy (ME) diet with 16% crude protein (CP) was fed ad lib. Average egg production for the Small Leghorns (SL) was about 60%, for white-egg hybrids (WL) about 75%, for brown-egg hybrids (BL) about 72%, for female line broiler breeders (BB) about 48%, and for broiler-cross pullets (B) about 51%. Average grams liveweight and grams feed intake per hen day were: SL, 1426 and 83.7; WL, 1809 and 104.9; BL, 2610 and 122.9: BB, 4197 and 156.2; and B, 4158 and 167.7. Partition equations which describe the data for SL, WL, BL, and BB, assuming 70% efficiency of use of feed ME for maintenance, tissue formation, and egg formation were: F = (.534 − .004T)W .653 + 2.76ΔW + .80EM and F = (.259 −.00259T)W.75 + 2.76ΔW + .80EM. Similar equations for B, assuming 65% efficiency use of ME, are: F = (.589 − .0044T)W.653 + 2.9ΔW + .85EM and F = (.275 − .00275T)W.75 + 2.9ΔW + .85EM. The terms are: F = grams feed/hen day; T = ambient temperature in °C; W = grams liveweight; ΔW = grams daily change in liveweight; EM = grams egg mass per hen day. Equations which assume 70% efficiency of use of ME are shown to predict feed intake of a diet containing 2890 kcal of apparent ME per kilogram for white and brown-egg layers and broiler-breeder pullets varying in individual body weights from about 1 to 5 kg. Equations, assuming 65% energetic efficiency, describe feed intake for a group of broiler-cross pullets.

Two studies were conducted to evaluate the effect of high or low protein diets on the body composition of broiler chicks at 28, 49, and 59 days of age. In the second study two broiler strains were also compared. In the low protein diets the protein and amino acid levels were reduced to approximately 80% of the levels in the control rations while maintaining the same calculated energy levels in both diets. Although not always statistically significant (P

Two floor pen studies were conducted to determine the minimum arginine level needed to support maximum weight gain and optimum feed conversion during the 4-7 week period of growth for both males and females. Floor feather counts were used as an additional criteria for determining the arginine requirement. The basal diets were calculated to contain 0.74 and 0.80% arginine based on the analyzed values for corn, corn gluten meal, skimmilk and soybean meal. Regression equations were calculated from the data obtained for the males only. Based on the regression equations, the calculated requirement for maximum weight gain, optimum feed conversion, and floor feathers is 1.09, 1.10, and 1.13% arginine, respectively. When expressed as a function of energy, the requirements would be 0.329, 0.332, and 0.341% arginine per megacalorie of metabolizable energy per kg. of diet, respectively. The differences in rate of gain data for the females were non-significant, indicating the requirement of the females to be less than the males. The female requirement, based on floor feathers, would appear to be 0.98% dietary arginine.

Two 14 day experiments were conducted to determine the effect of feeding pectin to chicks. In the first experiment simulated rye was mixed from purified ingredients and incorporated into feed in the place of normal rye. The growth of chicks receiving the simulated rye diet was depressed at day seven. When simulated rye without pectin was fed, growth was improved significantly. The addition of penicillin to the simulated rye diet eliminated the growth depression. In the second experiment pectin was added to a balanced corn-soybean ration at levels of 0, 1.5, 3.0, 4.5, and 6.0% of the diet. Each increase in the level of pectin up to 4.5% gave a significant decrease in weight gain. Penicillin supplementation of all diets containing added pectin gave a significant increase in growth. Sticky feces were evident in all chicks fed pectin at concentrations above 1.5% regardless of the presence of penicillin. It is concluded that feeding diets containing pectin to growing chicks will depress growth in a manner resembling the depression observed when feeding diets containing high concentrations of rye.

Chicks which were hatch-mates were placed in rearing facilities 4 hr and 24 hr after removal from the hatchers. One-half of the birds placed at each of these times received only water for 12 hr before being given access to feed. The other half received both water and feed simultaneously. Birds that were placed in the pens 4 hr after removal from the hatchers were significantly (P≤.01) heavier at 28, 49, and 56 days of age than birds which were held in the hatchery for 24 hr prior to placement. There were no significant effects on the birds’ weight or feed conversion which could be attributed to the birds receiving only water for 12 hr or initially receiving both water and feed. There were no significant interactions between the time the birds were placed and whether they initially received only water or water and feed. Three studies were conducted to evaluate the effect of adding various supplements to the drinking water for the first 24 to 72 hr on the weight and feed conversion of broiler chickens. There were no benefits from adding 10% sucrose for 24 hr or 5% sucrose for 72 hr. In one trial, there was a significant (P

The sensitivity of several bioassays was determined using soybean meal and two autoclaved soybean meals. Chick growth study results revealed that a four percent difference in weight gain was sufficient to show statistical significance (P less than .05) between the diets. Lysine quantities and digestibility values were compared using excreta obtained from intact (excreta collected on mats or in bags), cecectomized. and ileal-cannulated roosters. A 30% difference in lysine quantity in the excreta (collected on mats) was required to detect statistically significant effects of different diets fed to intact birds. Using intact birds (excreta collected in bags), cecectomized, and cannulated birds, differences in lysine quantity of 41, 42, and 67% were required to show statistically significant effects. Results showed that altering birds did not significantly change lysine values obtained nor reduce variability among birds (P greater than .05).

Six experiments were conducted with broiler cross male chicks to determine the available lysine requirement during the 7–9 week growing period. The birds were reared from day-old to 7 weeks of age on commercial type broiler rations. At 7 weeks of age the birds were group-weighed by pens and the pens ranked according to average weight and blocked on this basis. The treatments were randomly assigned within each block. Graded levels of lysine from L-lysine · HCl were added to lysine deficient basal rations which had been formulated based on available lysine values of 0.26, 3.09, 0.71 and 1.04% for corn, soybean meal, corn gluten meal and sesame meal, respectively. Using regression analysis the minimum available lysine requirement was calculated for this period. The minimum lysine requirement for male broilers during this period was 0.68% under optimum growing conditions. In one experiment the requirement appeared to increase under summer stress conditions. When expressed as a function of energy this would be 0.201% available lysine per mega Calorie M.E. per kg. of diet.

Four experiments were conducted studying the effects of inorganic sulfate supplementation fed to floor as well as battery reared broiler chicks. A significant growth response was obtained by the addition of 0.15% dl -methionine to a corn-soy basal ration containing 0.66% total sulfur amino acids. Increasing the methionine level to 0.30% did not produce a further significant growth response. The addition of 0.16% sodium sulfate was most effective in stimulating growth in chicks in this study. Furthermore, supplementing the diet with dl -methionine produced a significant improvement in feed conversion while the addition of up to 0.64% sodium sulfate did not have a similar effect. Somewhat similar results were obtained when potassium sulfate replaced sodium sulfate in the diet. No significant differences were observed in growth rate when ammonium sulfate, sodium sulfate or potassium sulfate were compared in an experiment where floor reared broiler chicks were fed practical rations. However, MHA was a significantly better converter of feed to gain than any of the inorganic sulfate sources. Results from Experiment 4 where several ratios of MHA and potassium sulfate were supplemented to a corn-soy diet and fed to floor reared broiler chicks, indicated that the optimal inorganic sulfate supplementation is between 25 and 50% of the supplemental sulfur amino acid needed to meet accepted requirements. At the 25% supplementation level, inorganic sulfate would provide about 6% of the total sulfur in practical diets.

Three experiments were conducted to study the influence of mechanical feather removal on the xanthophyll content of broiler breast skin and feather tract. A reduction in the amount of xanthophyll in the breast skin and feather tract occurred when the birds were scalded and picked. The largest decrease occurred after scalding when the skin was considered and after picking when the feather tract was examined. The skin had a larger amount of xanthophyll per 100 cm.2 following picking than was present after scalding. Exposing the carcasses to the scald water for 60, 120 or 180 seconds resulted in no changes in xanthophyll content of either the breast skin or feather tract. When the carcasses were exposed for 60 or 90 seconds in another experiment, an increase in xanthophyll per 100 cm.2 of breast skin was found to occur as the scald time was increased. A decrease in the amount of xanthophyll per 100 cm.2 was noticed to occur after picking for either 20, 40, 60 or 80 seconds when scalded for 60 or 90 seconds. The xanthophyll per 100 cm.2 of feather tract decreased when picked after being scalded for 90 seconds.

Studies with broiler type chickens were conducted to determine the minimum tryptophan requirement for maximum growth, optimum feed efficiency and molted body feather count for the 4–7 week period of growth for both males and females. Basal diets analyzed to contain 0.158, 0.157, and 0.147% tryptophan using analyzed tryptophan values of 0.09, 0.01, 0.31, 0.70, 0.40, and 0.46% for corn, gelatin, corn gluten meal, soybean meal, peanut meal-45, and peanut meal-50, respectively. Based on the regression equations for males, the calculated tryptophan requirement for maximum growth, optimum feed efficiency, and molted body feather count for the 4–7 week period is 0.179, 0.170, and 0.172%, respectively for 3300 Kcal. of M.E. per kg. of diet. When expressed as a function of energy, these requirements would be 0.054, 0.052, and 0.052% tryptophan per megacalorie of M.E. per kg. of diet, respectively. Based on the equations for females, the calculated tryptophan requirement for maximum growth, optimum feed efficiency, and molted body feather count is 0.173, 0.163, and 0.172%, respectively for 3300 Kcal. of M.E. per kg. of diet, respectively.

Experiments were conducted to study the effects of diet on liver glycogen and body composition in the three-week-old chick. When percent protein and percent lysine were varied, liver glycogen concentration declined significantly as protein and lysine increased, 32.6 vs. 19.4 mg/g for the 14 and 35% protein diets, respectively. Carcass fat decreased and carcass moisture increased in a pattern similar to glycogen as protein and lysine increased in the diets. When seven levels of lysine were fed in isocaloric, isonitrogenous diets, glycogen content was not significantly different in any of the treatments. Liver glycogen was highest at the lowest energy level when dietary energy was increased and protein held constant. Carcass fat varied with the energy level but was also influenced by the amino acid balance. The data suggest that percent carbohydrate to percent fat ratio in the diet (both calculated) is an important factor affecting glycogen, but more research is needed to determine the mechanisms controlling the glycogen content of the liver.

Ileum anaerobe counts of chicks fed diets containing rye or pectin were two or three logarithmic cycles greater than chicks fed a corn-soybean diet. Average counts per centimeter of small intestine of chicks fed rye, pectin, or a corn-soybean diet were 7.5 × 109, 1.1 × 1010, 4.3 × 107 respectively, for 4 day old chicks and 7.8 × 109, 8.4 × 109 4.1 × 107, respectively, for 14 day old chicks. The counts were not altered by penicillin supplementation of the diets. When diets containing rye or pectin were fed, the intestinal population always contained a major butyric acid and gas producing component. Mean butyric acid concentrations produced by the flora from chicks fed rye, pectin, or a corn-soybean diet were 4.65 mM, 4.46 mM, 0.22 mM, respectively. The flora from chicks fed rye or pectin contained spore-formers which were 6 to 7 logarithmic cycles greater in number than from chicks fed the corn-soybean diet. Addition of penicillin to the diets always resulted in a large reduction in butyric acid and gas production and decreased the sporeformer counts about 5 logarithmic cycles. It is suggested that a penicillin sensitive, sporeforming organism that produces large amounts of gas and butyric acid fermentatively, depresses the growth of chicks fed rye or pectin. It is probable that the organism belongs to the genus Clostridium.