Abstract
Previous studies have shown that the muscle protein degradation rates of broiler are lower than those of layer chickens. In this study, we assessed proteolytic-related gene expression in the pectoralis muscle of layer and broiler chickens. The mRNA levels of atrogin-1/MAFbx and proteasome C2 subunit, but not those of ubiquitin, m-calpain large subunit, cathepsin B, or caspase-3, were lower in the skeletal muscle of the broilers than in the layers at 7 and 14 d of age. We infer that the lower muscle protein degradation of broilers than of layers at least partly relates to lower mRNA expression of atrogin-1/MAFbx and proteasome C2 subunit in the skeletal muscle of broilers.
