The effects of selected feeding programs on the reproductive performance and specific blood plasma chemistries of caged broiler breeder males and dwarf breeder females

Graduation date: 1985I. THE EFFECT OF FEEDING PROGRAMS ON REPRODUCTIVE TRAITS AND\ud SELECTED BLOOD CHEMISTRIES OF CAGED BROILER BREEDER MALES:\ud 1. FEED RESTRICTION LEVELS:\ud The effects of five different feeding levels (136, 125, 113,\ud 102, and 91 g/male/day of a 13.1% crude protein (CP), 3167 kcal ME/kg\ud feed) on the reproductive traits of adult broiler breeder males in\ud cages were evaluated from 30 to 60 weeks of age. Individual body\ud weights, semen volume, sperm cells per ejaculate, and fertilizing\ud ability were measured at 30, 40, 50, and 60 weeks of age. To assist\ud in measuring the effect of feed restriction on metabolism during\ud these periods, average hematocrits, plasma cholesterol, total\ud protein, and uric acid levels were analyzed.\ud Significant (P<.05) reductions were observed in average body\ud weights, semen volume, sperm cell numbers per ejaculate, testicular\ud weights, and hematocrits with feed restriction at the 91 g compared\ud to the 136 g feeding level. At 40 weeks of age the percentage of males producing semen was significantly reduced for the 102 and 91 g\ud compared to the 136 g feeding level. Average plasma cholesterol\ud levels were significantly increased at the 91 g compared to the 136 g\ud feeding level, but no significant effect (P>.05) was observed in\ud plasma total protein and uric acid levels. Correlation coefficients\ud were negative for plasma cholesterol to body weights, sperm numbers\ud per ejaculate, and testicular weights but positive for body weights\ud to hematocrits and testicular weights.\ud II. THE EFFECT OF FEEDING PROGRAMS ON REPRODUCTIVE TRAITS AND\ud SELECTED BLOOD CHEMISTRIES OF CAGED BROILER BREEDER MALES:\ud 2. FREE CHOICE, LOW ENERGY RATIONS OF 9, 7, AND 5 PERCENT\ud CRUDE PROTEIN:\ud Three isocaloric feeds consisting of 9, 7, and 5% CP each\ud containing 2315 kcal ME/kg were fed free choice to individually caged\ud broiler breeder males from 22 to 65 weeks of age. To obtain these\ud protein and energy levels, sand was incorporated into the rations at\ud levels ranging from 26.1 to 33.6% of the feed. The average daily protein intake per male was 18.7, 14.7, and 10.7 g for the 9, 7, and 5% CP, respectively, with an average caloric intake of 480 kcal ME. Individual body weights, semen characteristics, testicular weights, hematocrits, plasma cholesterol, total protein, uric acid and triglyceride levels were evaluated during each 4-week period from 24 to 44 weeks and also at 50 and 65 weeks of age. Average body weights from 24 to 32 weeks of age were significantly lower for the males fed 5% CP then those fed 9% CP rations. Semen volumes and sperm cell numbers per ejaculate were significantly reduced only at 24 weeks of age for males fed 5% CP feeds. At 65\ud weeks of age there were no significant differences among treatments\ud means for body weight, sperm cells numbers per ejaculate, nor testicular weights. Plasma cholesterol levels of males fed the 5% CP diet\ud were significantly higher at 28 and 32 weeks while levels of plasma\ud total protein were decreased at 28 weeks of age. Plasma uric acid\ud levels were consistently and significantly decreased as protein in\ud take was reduced. The results suggest that within the parameters of\ud this study broiler breeder males can be successfully maintained on\ud low energy (2315 kcal/ kg) feeds of 7% CP from 22 to 40 weeks and\ud then 5% CP from 40 to 65 weeks of age.\ud III. INFLUENCES OF 16 AND 17.5 PERCENT DIETARY PROTEIN AND\ud SUPPLEMENTAL METHIONINE ON THE REPRODUCTIVE TRAITS AND\ud SELECTED PLASMA CHEMISTRIES OF CAGED DWARF (dw) BROILER\ud BREEDER FEMALES:\ud A total of 240 individually caged dwarf (dw) broiler breeder\ud females were fed one of six isocaloric treatment diets (2740 kcal/kg)\ud containing 16 or 17.5% CP to which d,l-methionine (MET) was supple\ud mented at 0, .08, or .15% from 22 to 50 weeks of age. The resulting\ud dietary MET levels ranged from .256 to .424% and total sulfur amino\ud acids (TSAA) ranged from .527 to .718% of the rations. Treatment\ud means were compared for body weights, mortality, total egg produc\ud tion, egg weights, and egg fertility and hatchability resulting from\ud artificial insemination with .05 ml broiler breeder semen. Blood\ud plasma was analyzed at 32, 40, and 50 weeks of age for cholesterol, uric acid, total protein, and albumin as possible monitors of dietary\ud protein utilization and of the physiological effects of protein and\ud methionine levels on reproductive traits.\ud There were no significant differences observed among dietary\ud treatment means for body weights, mortality, total egg production,\ud fertility, nor hatchability from 24 to 50 weeks of age. Significant\ud differences were not observed among the treatment means for plasma\ud cholesterol, total protein, and albumin at 32, 40, or 50 weeks of\ud age. Between the two CP levels, plasma uric acid was significantly\ud increased for the females on 17.5% compared to those on 16% CP\ud rations. A consistent although nonsignificant trend of decreased\ud uric acid levels with supplemental methionine was observed only in\ud the females fed 16% CP diets and not in those on 17.5% CP.\ud Under the conditions of this experiment, protein requirements\ud for caged dwarf broiler breeder females from 22 to 50 weeks of age\ud appear to be satisfied with daily dietary intakes of 20.3 g CP, 325\ud mg MET, and 670 mg TSAA