PERFORMANCE OF BROILER CHICKS FED TWO DIETARY PROTEIN LEVELS (18 AND 22%), TWO NEEPAWA WHEATS (14.5 AND 21.0% PROTEIN), AND SIX L-LYSINE LEVELS

Abstract

Day-old male broiler chicks were fed 14.5 and 21.0% protein Neepawa wheats as ingredients in broiler diets to 4 wk of age. Two levels of dietary protein (18 and 22%) and six levels of added L-lysine HCl (L-lysine) (0.0, 0.06, 0.12, 0.18, 0.24, and 0.30%) were used with each wheat. The desired dietary protein contents were obtained by varying the proportions of the wheats and soybean meal. Body weights and feed-to-gain ratios were significantly affected by the three variables. Within the 18% protein diets, the diet containing 14.5% protein wheat and supplemented with at least 0.18% L-lysine gave maximal growth and most efficient feed conversion. Maximal growth was not obtained on any of the 18% protein diets with 21.0% protein wheat, regardless of L-lysine supplementation. With the 22% protein diets, L-lysine supplementation up to 0.24% of the diet improved the body weight and feed conversions of the chicks when the diet contained 21.0% protein wheat, and generally the results were not different from those obtained when the diet contained the 14.5% protein wheat. L-lysine supplementation of the 22% protein diet containing the 14.5% protein wheat did not significantly affect growth or feed conversion. High-protein wheat supplemented with adequate L-lysine can be fed to chicks and thereby substantially reduce the amount of supplemental protein required.