Performance, carcass traits, and relative organ weight of broiler supplemented by guanidinoacetic acid: A meta-analysis

Abstract

Guanidinoacetic acid (GAA) is formed by the arginine and glycine that are catalysed by arginine:glycine amidinotransferase in the kidney. In the liver, GAA is methylated by s-adenosyl methionine and converted to creatine, then deposited into muscle as energy supply. This meta-analysis was done by integrating 20 articles from various journals. Supplementation doses ranged from 0 to 8000 ppm/kg feed. The mixed model methodology was employed with GAA level and broiler strain as fixed effects and studies as random effects. The results showed that increasing GAA level improved average daily gain day 0-21 and reduced feed conversion ratio day 0-35 (P<0.05). A higher GAA also accompanied by decreasing relative liver weight (P<0.05). GAA supplementation did not affect average daily feed intake and percentage of carcass traits (carcass, legs, breast, wings, drum, thigh) and other parameters such as abdominal fat, gizzard, heart, bursa, thymus and spleen (P>0.05). It was concluded that supplementation of GAA improved the performance of broilers.