Evaluation of Dietary Protein Levels for White Leghorns in the Grower and Subsequent Layer Periods

Abstract

RECENT literature on the effect of protein levels on the overall performance of chickens in grower and/or layer periods shows a wide disparity in experimental design. For simplicity and clarity of presentation the investigators and their designs are shown in Table 1. As indicated in the table, different protein levels were fed at different ages under varying management practices. However, none of the studies were designed to test the effect of pullets reared on litter and fed varying protein levels at different ages, with subsequent transfer to layer cages and fed several protein levels. Accordingly, experiments were designed to study the effect of this treatment on grower and layer performance. EXPERIMENTAL PROCEDURE Day-old S.C. White Leghorn strain A pullets were used in years 1 and 2 (experiment 1) and day-old S.C.W.L. strains B and C in year 2 (experiment 2); both experiments were set up in March one year apart. . . .