Effects of Low-Protein Diets on Growth Performance and Serum Biochemical Parameters of Hetian Chicken

1980 Hetian chickens(1-day old) were randomly separate into 2 groups(control and treatment groups) based on body weight with 3 replicates per group,330 birds per replicate.The diets in control group are formulated based on the amino acid model and crude protein level of Nutrient Requirements of Chinese Color-feathered chicken(NY/T 33-2004).The diets in treatment group are based on the amino acid model of NRC(1994) and 1% lower than the control diets in crude protein level.The growth performance and serum biochemical parameters were determined at day 28,42,75 and 105.The results showed as follows: the low-protein diets had no significant effect on body weight at each determination day except at day 28(P0.05).There were no significant differences on growth performance between two groups at each stage(P0.05).Serum total protein level and ALP(Alkaline phosphatase) activity were slightly higher in treatment group(P0.05).However,The BUN(Blood Urea Nitrogen) and UA(Uric Acid) were slightly lower than control group(P0.05).From day 28 to day 105,serum total protein level significantly increased(P0.05),but BUN,UA and ALP were on a decreased trend(P0.05).