Effects of dietary supplementation of Guanidino acetic acid and L- arginine on performance, blood metabolites and carcass characteristics of Japanese quails

In this study, 600 one-day Japanese quails were assigned to six treatments with five replicates of 20 chicks per replicate in 2×3 factorial arrangement based on a completely randomized experimental design. Two levels of L- arginine (the recommended level of NRC and 10% higher than the recommended level by NRC) and three levels of Guanidino acetic acid (GAA) (0, 0.6 and 1.2 g/kg diet) were used in this study. Body weight and feed intake were recorded at the end of the experiment. On day 42, blood samples from two chicks of each replicate were taken from wing vein for some blood metabolites measurements. Then, thechicks wereslaughtered for carcass and internal organs investigations. L-arginine supply at 10% over NRC recommendation increased daily feed intake, and improved body weight gain and feed conversion ratio significantly (P<0.05). L-arginine supply at 10% over NRC recommendation and 1.2 g GAA/kg diet increased feed intake and improved feed conversion ratio (P<0.05). The relative weight of breast and thigh increased and abdominal fat decreased significantly by L-arginine supplementation (P<0.05). The main effects of L- arginine and GAA on blood metabolites were significant (P<0.05), with a reduction effect on cholesterol, triglyceride and VLDL concentrations and enhancement effect on HDL content. L-arginine supply at 10% over NRC recommendation with 0.6 and 1.2 g GAA/kg diet significantly decreased blood cholesterol, triglyceride and VLDL and increased HDL concentrations in compared to those fed L- arginine at NRC recommendation (P<0.05). Therefore, the findings of this study showed that providing extra L- arginine than the NRC recommendation with 0.6 g GAA/kg diet significantly improved performance and decreased blood serum cholesterol, triglyceride, and VLDL in Japanese quails (P<0.05).