Threonine and lysine requirements for maintenance in chickens

摘要: In order to describe the response of broiler breeder hens dietary amino acids and develop an effective model for precise feeding these birds after sexual maturity, accurate estimates amounts each acid required maintenance egg production are needed. The requirement threonine lysine were estimated in two different experiments by measuring nitrogen balance adult male cockerels. Measured a diet first-limiting or fed intubation day 4 d give range intakes (unbalanced series) from 0 239 mg threonine/kg 40 lysine/kg body weight. To confirm that was obtained not protein, second series diets used (balanced which synthetic added unbalanced series. A nitrogen-free containing energy, vitamins minerals made available ad libitum during period, ensure remained positive energy balance. period three days excreta collected colostomy bags (threonine) trays (lysine) time. content determined on dried homogenised samples. resultant linear regression equations describing effect retention were: N = -230.4 (± 27.6) + 4.134 0.274) I (R 2 91.9) -256.8 37.7) 6.89 1.37) 70.8), respectively, where is intake mg/kg weight day. maintain at zero therefore be 56 37 day, respectively.