Feed restriction during growth increase plasma growth hormone (GH) concentrations observed in domestic birds fed practical diets (Proudman et al., 1981). Nguyen et al., 2005 indicated that lower protein diet (17% CP) reduced live body weight and daily weight gain at early ages. Dietary protein levels higher than 17% CP did not show any significantly effect on growth performance, although increasing dietary protein levels positively improved growth performance and feed utilisation. Dietary energy contents of 12.54 and 13.38 MJ ME/kg did not alter the growth performance of the Betong chicks.