The tryptophan requirement of male and female broilers during the 4-7 week period

Studies with broiler type chickens were conducted to determine the minimum tryptophan requirement for maximum growth, optimum feed efficiency and molted body feather count for the 4-7 week period of growth for both male and females. Basal diets analyzed to contain 0.158, 0.157, and 0.147% tryptophan using analyzed tryptophan values of 0.09, 0.01, 0.31, 0.70, 0.40, and 0.46% for corn, gelatin, corn gluten meal, soybean meal, peanut meal-45, and peanut meal-50, respectively. Based on the regression equations for males, the calculated tryptophan requirement for maximum growth, optimum feed efficiency, and molted body feather count for the 4-7 week period is 0.179, 0.170, and 0.172%, respectively for 3300 Kcal. of M.E. per kg. of diet. When expressed as a function of energy, these requirements would be 0.054, 0.052, and 0.052% tryptophan per megacalorie of M.E. per kg. of diet, respectively. Based on the equations for females, the calculated tryptophan requirement for maximum growth, optimum feed efficiency, and molted body feather count is 0.173, 0.163, and 0.172%, respectively for 3300 Kcal. of M.E. per kg. of diet, respectively.