Effects of Dietary Tryptophan Levels on Growth,Whole-body Nutrient Retention and Hypothalamic Serotonin Concentration in Yellow-feathered Broilers Aged 1 to 21 Days
The trial was conducted to investigate the effects of dietary tryptophan (Trp) levels on growth performance, whole-body nutrient retention, serum free Trp, and the concentration of hypothalamic serotonin (5-HT) and free Trp in order to determine total and digestible Trp requirements of yellow-feathered broiler chicks aged 1 to 21 days based on quadratic regression models. Two thousand 1-day-old yellow-feathered broiler chicks were used. Five dietary treatments were compared in a 5×2 factorial arrangement wi...