Effect of dietary guanidinoacetic acid or nucleotides supplementation on growth performances, carcass traits, meat quality and occurrence of myopathies in broilers

This study was conducted to evaluate the effects of diets supplemented with nucleotides and guanidinoacetic acid (GAA) on broiler chickens growth performance, blood metabolites, leukocyte differential count, mitotic activity of satellite cells, carcass yield, meat quality, chemical analysis of breast muscle, incidence of breast myopathies, and skin lesions from 0 to 42d. A total of 600 one-day-old male broiler chickens were randomly distributed among three treatments with eight replicates and 25 broiler chickens per pen. Treatments consisted of a control diet (CD), the CD + one g/kg of nucleotides (fed from 0 to 28 d, afterwards broilers were fed CD) and the CD + 0.6 g/kg of GAA (fed from 0 to 42 d). On 10 d, broiler chickens fed with GAA had an improved feed conversion ratio (FCR) (P < 0.05), increased BWG (P < 0.05), and plasmatic concentration of creatine kinase (P < 0.05) when compared to broiler chickens fed the CD. On 28 d, breast meat of broiler chickens fed with GAA showed a reduction in fat content, compared to the nucleotides. Broiler chickens fed with GAA had a reduction in dermatosis and incidence of moderate and average scores of wooden breast (WB) scoring, besides the proportions of severe and average scores of white stripping (WS) scoring at 42 d, compared to broiler chickens fed diets supplemented with nucleotides. In conclusion, supplementation of nucleotides increases the incidence of breast myopathies, without affecting other variables and GAA supplementation improves broiler chickens growth performance compared to control group from 0 to 10 d and reduced the severity of myopathies and the occurrence of dermatosis at 42 d.