Influence of Metabolizable Energy Feeding Sequence and Dietary Protein on Performance and Selected Carcass Traits of Tom Turkeys

Abstract

Two identically designed experiments were done to determine the effects of reducing dietary MEn concentration during late growth and of dietary protein concentration on performance and selected carcass traits of turkey toms. A complete factorial arrangement of three MEn feeding sequences and four dietary protein concentrations was used. The MEn feeding sequences were 102% of MEn concentrations listed by NRC (1984), from 1 to 119 days of age (M), 102% MEn for 1 to 42 days followed by 108% MEn from 42 to 119 days (M-H), and the same as the M-H sequence except the 102% MEn diets were fed from 105 to 119 days (M-H-M). The four dietary protein concentrations were 93, 100, and 107%, of NRC recommended protein concentrations, in which essential amino acid (EAA) levels met or exceeded NRC recommendations, and 107% of NRC, in which the EAA concentrations were at least 107% of NRC recommendations. Feeding diets of the M-H and M-H-M MEn sequence improved feed efficiency (P ≤ .01) in both experiments as compared with the M sequence. Toms fed the M-H or M-H-M sequences in Experiment 1, but not in Experiment 2, were heavier at the finish than those fed the M sequence. Body fat of toms was increased (P < .05) by feeding the M-H MEn sequence, compared with feeding the M or M-H-M sequences in Experiment 1. No dietary MEn effects on body fat were observed in Experiment 2. Dietary protein concentration did not modify the effects of MEn feeding sequence and there were no effects of protein concentration on BW or feed efficiency in either experiment. Fat pad and breast meat weights were affected differently by dietary treatments in the two experiments, possibly because of differences in ambient temperature during the last 3 to 4 wk of the experiments.