Guanidinoacetic acid as a functional additive in broiler nutrition: insights into performance, carcass, antioxidant capacity, and health

SUMMARY: Nowadays, broiler chicken is considered an important source of high-quality protein in the human diet; hence, poultry production makes an essential component of world food security. The increase in poultry products demand warrants optimum production efficiency along with heat stress, disease management problems and antibiotic resistance. Guanidinoacetic acid (GAA), a creatine precursor, has been of interest for its potential to improve growth efficiency, meat quality and general health in birds. In this review, effects of GAA supplementation on growth performance, carcass traits and meat quality, antioxidant activity, immune function and intestinal health in broiler chickens were summarised. Previous works have shown that GAA supplementation had positive effects on feed efficiency, daily gain and muscle yield especially at heat stress environment. A supplemental dose of GAA of 0.6–1.2 g/kg in broiler diets has been noted to be sufficiently effective as a growth promoting agent and improve meat quality, due to the promotion on the activity of antioxidant enzymes and immune responses. In addition, GAA supplementation may also modulate genes in intestinal mucosal morphology and gut health. While the results are promising, the variability in outcomes between studies (for instance, dosage of GAA incorporated into feed supplementation duration, environment, etc.), indicates that additional research is needed for optimal use of GAA in a given poultry production system. The GAA supplementation is suggested to be a cost-effective and sustainable approach to poultry production delivering productivity and bolstering welfare.