Influence of amino acid supplementation of low-protein diets and metabolizable energy feeding sequence on performance and carcass composition of toms.

An experiment was conducted to determine the influence of essential amino acid (EAA) supplementation of low-protein diets and of MEn feeding sequence on performance and selected carcass characteristics of turkey toms. Feeding diets containing 93 or 100% of the protein and 100% of the EAA concentrations recommended by NRC (1984) or a diet containing 93 and 107% of the recommended protein and EAA concentrations, respectively, had no effect on BW or feed efficiency of toms at 104 or 117 d of age. Dietary protein-EAA concentrations also had no effect on carcass and breast meat yields or proximate composition of carcasses at 105, 112, or 118 d of age, irrespective of MEn feeding sequence. Feeding diets supplying 108% of the MEn concentrations (MH) listed by NRC from 41 to 104 d improved BW (P < .02) and feed efficiency (P < .01) as compared with feeding 102% (M) of the MEn listed by NRC, but only the improvement in feed efficiency was evident at 117 d. Feeding diets supplying 108% MEn from 41 to 104 d, followed by the 102% MEn diet from 104 to 117 d (MHM), resulted in the same 117-d BW and feed efficiency as feeding the MH MEn sequence from 41 to 117 d. Metabolizable energy feeding sequence had no consistent effect on carcass or breast meat yields. Feeding the MHM sequence decreased (P < .05) fat pad and carcass fat of toms processed at 105, 112, and 118 d, compared with the MH feeding sequence. However, fat pad and carcass fat of toms fed the MHM MEn sequence generally exceeded those of toms fed M MEn diets from 1 d to time of processing.