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 am ino acid (EAA) supplementation of low-protein diets and of ME(n) feedi ng sequence on performance and selected carcass characteristics of tur key toms. Feeding diets containing 93 or 100% of the protein and 100% of the EAA concentrations recommended by NRC (1984) or a diet containi ng 93 and 107% of the recommended protein and EAA concentrations, resp ectively, 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 ca rcass and breast meat yields or proximate composition of carcasses at 105, 112, or 118 d of age, irrespective of ME(n) feeding sequence. Fee ding diets supplying 108% of the ME(n) concentrations (MH) listed by N RC from 41 to 104 d improved BW (P < .02) and feed efficiency (P < .01 ) as compared with feeding 102% (M) of the ME(n) listed by NRC, but on ly the improvement in feed efficiency was evident at 117 d. Feeding di ets supplying 108% ME(n) from 41 to 104 d, followed by the 102% ME(n) diet from 104 to 117 d (MHM), resulted in the same 117 d BW and feed e fficiency as feeding the MH ME(n) sequence from 41 to 117 d. Metaboliz able energy feeding sequence had no consistent effect on carcass or br east meat yields. Feeding the MHM sequence decreased (P < .05) fat pad and carcass fat of toms processed at 105, 112, and 118 d, compared wi th the MH feeding sequence. However, fat pad and carcass fat of toms f ed the MHM ME(n) sequence generally exceeded those of toms fed M ME(n) diets from 1 d to time of processing.