The Nutritional Value of Wheat Protein for Early Growth of Layer and Broiler Breeder Pullets

Abstract

Six hundred and forty-eight White Leghorn chicks, 408 broiler breeder pullets and 92 Cornish males were utilized in two feeding trials to study the limiting amino acids in wheat protein diets. Results of Trial 1 with White Leghorn chicks indicate that rate of growth was depressed by reducing dietary protein from 20 to 15%. Body weight was not significantly improved by the addition of methionine, leucine, threonine, arginine, valine and isoleucine in various combinations to a wheat-lysine diet. However, treatments that included threonine consistently resulted in slightly heavier birds at four weeks of age than the wheat-lysine diet.Results with broiler breeder pullets showed that a 15% protein wheat-lysine diet supported better growth than a wheat-soya diet. Supplemental dietary threonine in the wheat-lysine diet significantly improved growth. Also, diets fortified with threonine and valine improved the growth rate supported by the wheat-lysine diet.Results with Cornish males indicate that wheat protein is limiting in lysine, threonine and valine. A marked response was observed by the addition of both threonine and valine to the wheat-lysine diet.