Modulating the Growth Curve in Broiler Chicken Through Varying Balanced Protein Regimen (Conventional All Step-down)

Background: Selecting the appropriate amino acid levels according to age of modern broiler chicken is critical since proteins are costly. This study, therefore, evaluated performance by modulating growth curve through varying balanced protein (BP) regimen under conventional all step-down phase feeding. Methods: In total, 1750 one-day-old straight run chicks (Hubbard) were randomly allocated 10 treatments, replicated 7 times with 25 broilers. The 3 diets; a high BP (HBP) 1.2% standardized Ileal digestible lysine (SIDLys), medium (MBP) 1.1% SIDLys and low (LBP) 1.0% SIDLys, offered in starter, grower finisher phases as HHH, MMM, LLL, HHM, HHL, MML, HLL HML. Result: Higher (P less than 0.05) average BW BWG observed HMM group starter period. greater FI, however, was HHH MLL groups phases. had better FCR dressed carcass weight, breast yield, drum stick thigh weights. group, moreover, heavier abdominal fat, thigh, spleen, thymus bursa Fabricius. similarly, higher serum glucose, cholesterol, urea concentrations antibody titers against NDV IBDV. conclusion, HBP diets improved performance, characteristics, blood metabolites immunity chicken.