An evaluation of a stepdown amino-acid feeding program for commercial pullets to 20 weeks of age

Two experiments were conducted to study the use of a feeding program based on dietary amino-acid levels for commercial egg-production replacement pullets from 8 to 20 wk of age. HyLine W-36 pullets were used in Experiment 1; and HiSex White pullets were used in Experiment 2. All pullets were fed a starter diet calculated to contain 21% CP for the first 8 wk of age. From 8 to 20 wk of age, they were fed 10 series of diets calculated to provide various levels of TSAA, lysine (Lys), tryptophan (Trp), and arginine (Arg) at various ages. The levels of each of these amino acids were lowered every 2 weeks. The following levels of amino acids, based on calculated values suggested for corn and soybean meal, were found to be adequate from 8 to 20 wk, with linear reductions at biweekly intervals: .54 to .42% TSAA (.28 to .21% methionine), .64 to .48% lysine, .18 to .14% tryptophan, and .96 to .78% arginine.