Impact of Glycine Supplementation to Dietary Crude Protein Reduction in Broiler Chickens

Abstract

A 21-day experiment was conducted to evaluate the effect of dietary reduction of crude protein (CP) concentrations with graded levels of supplemental glycine (Gly) on growth performance of broiler chickens. Day-old chicks (n = 250) were randomly divided into five treatment groups which were divided into five replicates of ten chicks each in a completely randomized design. The treatments were as follows: T1 comprised of the control group with a standard CP diet (SCPD; 3100 kcal ME/kg and 22% CP) while T2, T3, T4 and T5 comprised of groups fed reduced CP diets (RCPD; 3100 kcal ME/kg and 19% CP) with supplemental Gly at 0.2, 0.4, 0.6 and 0.8% graded levels, respectively. Weight gain (WG), feed intake (FI) and feed conversion ratio (FCR) data was collected on a weekly basis. Final body weight and weight gain of birds fed control and 0.8% Gly diets were similar and higher (P < 0.05) than those fed other treatment diets. A similar FCR was recorded among birds fed control, 0.6% and 0.8% Gly diets but lower (P < 0.05) than other treatment groups. Therefore, a minimum level of 0.6% Gly supplementation is necessary to optimized performance of broilers (21-d old) fed RCPD.