Effect of plane of nutrition from starting through the breeder period on the reproductive performance of tom turkeys.

Large type breeder toms were given high (HP) or low (LP) planes of nutrition from hatching to 29 weeks of age. Birds from each rearing treatment were divided and HP or LP breeder rations were fed to 58 weeks. Protein and energy levels of the HP feeds approximated National Research Council (NRC, 1977) recommendations while LP feeds involved substitution of corn, fat, and soybean meal for wheat, barley, and oats. Energy-protein ratio and relative essential amino acid levels were similar between treatment, respective of age. Toms given LP feeds weighed less than HP through the first 9 weeks after hatching, but they were similar thereafter until 29 weeks. Reduction in feed conversion with the LP regimen was only significant during the 18 to 21-week interval. Feed intake during the breeder period was unaffected by treatments. Toms receiving the LP breeder feed reduced their weight, particularly when preceded by LP rearing. Mortality was inversely related to average body weight with each treatment. Reproductive capacity, as judged from semen yield and sperm concentration, was more favorable when toms were reared on LP than HP feeds but only during the first few weeks of the breeder period. The LP feed given through the breeder period also proved more favorable than HP feed, particularly at the end of production. Carcass evaluations at 29 and 58 weeks indicated that the LP regimens reduced depot fat while increasing relative testes weight.