Supplementation of guanidinoacetic acid and betaine improve growth performance and meat quality of ducks by accelerating energy metabolism

This study was conducted to investigate the effects of guanidinoacetic acid (GAA) and betaine on growth performance, meat quality and metabolism of ducks. A total of 384-one-day-old Cherry Valley meat ducks (55.75 +/- 0.55 g) were randomly assigned to four treatments with 6 replicates of 16 ducks. Ducks were fed a basal diet (control) or a test diet supplemented with 0.6 g GAA/kg, 2.0 g betaine/kg, or 0.6 g GAA/kg + 2.0 g betaine/kg. The results showed that compared with the control group, GAA and betaine improved feed conversation ratio from day 1 to 14 and 1 to 35 and body weight at 35 days of age (p < .05). GAA and betaine increased breast muscle percentage while reduced abdominal fat percentage, and drip loss and shear force of breast muscle (p < .05). GAA and betaine lowered free serine, methionine, tryptophan and total amino acid contents in muscles, increased free serine, aspartic acid, phenylalanine and tryptophan contents in plasma (p < .05). There was a synergistic effect on non-esterified fatty acid, lactic acid and uric acid between GAA and betaine. GAA and betaine increased the creatine kinase activity in plasma and creatine and ATP content in breast muscle, decreased the lactate dehydrogenase and L-arginine: glycine amidino transferase activities (p < .05). In conclusion, supplementation of GAA and betaine improved the growth performance and meat quality of ducks by accelerating energy metabolism. There was a synergistic effect on NEFA, LA and UA concentrations in plasma of ducks between GAA and betaine.