| The development and validation of a bioenergetic growth model for broiler breeder males is described. Sensitivity analysis revealed that growth was most influenced by the efficiency of energy utilization, amount of feed allocated, and the metabolizable energy value of the feed. It was also shown that adult metabolic rate played a critical role in body weight gain, especially as the bird ages. Validation of the model showed that the model was accurate at predicting body weight within ±100 grams.; Experiments were conducted to determine how different feeding schedules, dietary crude protein levels, and rearing management affect the growth of broiler breeder males. Males grown on a daily feed schedule were 4% more efficient at utilizing nutrients than males reared on an alternate day feed schedule. Similarly, males reared on a 17% crude protein diet were 7% more efficient than on a 14% crude protein diet. Finally, it was determined that males grown intermingled with females were able to consume between 10 to 14 grams more feed per day than the females from 13 to 21 weeks of age.; Experiments were conducted to investigate the effect of feed allocation programs from 1 to 28 weeks of age. In the first experiment, males were grown using either a “concave” or “linear” shaped feed allocation program, while in the second experiment, males were grown utilizing either a “concave” or “sigmoid” shaped program. Body weights of “linear” and “sigmoid” grown males were larger only from 8 to 16 weeks of age in the respective experiments. Application of the bioenergetic growth model suggested that males were “stealing” feed from the female feeders from 22 to 26 weeks of age and this caused increased male mortality. Male mortality appeared to be affected by the shape of the rearing feed program, because “linear” and “sigmoid” grown males exhibited a higher incidence of mortality from 30 to 64 weeks of age than “concave” grown males. |
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