Effects of environmental temperature and dietary energy on energy partitioning coefficients of female broiler breeders.

摘要: With increasing disparity between broiler breeder target weights and growth potential, maintenance energy requirements have become a larger proportion of total intake. Because is partitioned to egg production at lower priority than maintenance, accurate prediction important for practical feed allocation decisions. Environmental temperature affects the requirement by changing rate heat loss environment. In ME system, (energy lost) part (ME). current study, nonlinear mixed model was derived predict partitioning hens under varied conditions. At 21 wk age, 192 Ross 708 were individually caged within 6 controlled environmental chambers. From 25 41 wk, 4 treatments (15°C, 19°C, 23°C, 27°C) randomly assigned chambers 2-week periods. Half birds in each chamber fed high-energy (HE; 2,912 kcal/kg) diet, half low-energy (LE; 2,790 diet. The regression included normally distributed random term representing individual hen quadratic response temperature, linear ADG mass (EM) coefficients. assumed that BW gain not influenced because homeothermic, cellular processes associated biochemical occurred narrow core body range. Residual intake (RFI) residual (RME) used estimate efficiency. A effect on MEm predicted ( < 0.0001), with minimum expenditure 24.3°C. Predicted 21°C 92.5 kcal/kg; EM 2.126 1.789 kcal/g, respectively 0.0001). Birds HE diet more efficient, RME LE (-0.63 vs. 0.63 kcal/kg), translating 135.2 136.5 kcal/kg, respectively. experiment, optimal biological efficiency 24.3°C feed-restricted breeders