An evaluation of threonine requirements of young turkeys

Two experiments were conducted to evaluate the Thr requirements of male Large White turkeys from 3 to 6 and 6 to 9 wk of age. One group of turkeys was fed to 3 wk using nutritionally adequate diets and fed test diets from 3 to 6 wk; another group of turkeys was fed to 6 wk using nutritionally adequate diets and fed test diets from 6 to 9 wk. Test diets were composed of peanut meal, soybean meal, corn, and grain sorghum as intact protein sources and were supplemented with amino acids. Peak performance of turkeys fed the test diets was equivalent to that of turkeys fed conventional corn-soybean meal diets formulated to meet NRC (1994) standards. Estimates of Thr requirements for weight gain were 0.92 and 0.86% for 3 to 6 and 6 to 9 wk, respectively. For feed conversion, estimates of Thr requirements were 0.87% and 0.84% for 3 to 6 and 6 to 9 wk, respectively. The results of the two experiments reported herein would suggest that the Thr requirements suggested by NRC (1994) for turkeys up to 9 wk of age are safe estimates; they may slightly overestimate the requirements but not by a large margin.