Combined effects of guanidinoacetic acid, coenzyme Q and taurine on growth performance, gene expression and ascites mortality in broiler chickens.

High levels of guanidinoacetate acid (GAA) deteriorate growth response in broiler chickens. We propose using coenzyme Q , an antioxidant, and taurine (TAU), a methyl donor, to cope with the situation when high level of GAA included in diet. GAA was supplemented at 0 (control), 0.75, 1.5 and 2.25 g/kg in isoenergetic and isonitrogenous diets and fed to broilers (Cobb 500) from 1 to 40 days post-hatch. Three additional diets were prepared by adding CoQ (40 mg/kg), TAU (40 mg/kg) or their combination (both CoQ and TAU at 40 mg/kg) to the 2.25 g/kg GAA group. The experimental design used was a completely randomized design. While weight gain (p = 0.038) and feed conversion ratio (p = 0.024) improved when GAA added at 1.5 g/kg, higher supplementation (2.25 g/kg) deteriorated these responses. These responses, however, were significantly restored by using CoQ , TAU or their combination. Abdominal fat deposition was significantly decreased when TAU added to broiler diets by virtue of upregulating peroxisome proliferator-activated receptor alpha. Supplementing broiler diets with CoQ and TAU or their combination significantly decrease ascites mortality. In conclusion, CoQ and TAU have shown beneficial effects when high level of GAA included in broiler diets.