Growth in pigs is regulated in large part by the brain neuroendocrine GH-IGFs axis (Hall et al., 1986). GH can influence skeletal and muscle growth via direct and indirect effects on protein, lipid and carbohydrate metabolism (Pell and Bates, 1990) and fulfills its function of growth promotion through improving the production of IGF-I. IGF-I can stimulate amino acid uptake and protein synthesis in muscles and can greatly reduce the rate of protein breakdown within muscle fibers (Liu et al., 2008).