Two experiments were conducted to determine the effects of diets containing low oligosaccharide soybean meals (LOSBM) on growth performance, meat yields, and physiological variables of broilers during a 6-wk production period. In experiment 1, six hundred Ross × Ross 708 male chicks were randomly distributed to 24 floor pens (25 birds per pen). Birds were fed corn-soybean meal-poultry by-product meal-based diets with either low oligosaccharide (LOSBM) or conventional SBM (SBM) from 1 to 40 d of age. In experiment 2, one thousand five hundred Ross × Ross 708 male chicks were randomly distributed to 60 floor pens (25 birds per pen). Broilers were fed corn-soybean meal-poultry by-product meal-based diets containing 1 of 3 SBM sources (SBM, LOSBM, or ultra-low oligosaccharide SBM (ULSBM)) and formulated with moderate or reduced AMEn concentrations (25 kcal/kg reduction) resulting in a 3 × 2 factorial design. Diets were formulated using AMEn and digestible amino acid values determined from previous research utilizing the same SBM types. Variables measured consisted of body weight gain, feed intake, feed conversion ratio, mortality, carcass weight and yield, abdominal fat percentage, total breast meat weight and yield, digesta viscosities and pH, plasma nonesterfied fatty acids, plasma glucose, and plasma triglycerides.
In experiment 1, broilers fed diets containing LOSBM had increased body weight gain (P = 0.020) and decreased feed conversion (P < 0.001) from 1 to 14 days of age. Abdominal fat percentage was higher (P < 0.001) for birds fed LOSBM vs. SBM. In experiment 2, no differences were observed for interaction effects or main effects of energy concentration. Feed conversion ratio was lower (P < 0.001) for broilers fed diets containing ULSBM vs. LOSBM and SBM from 1 to 28 and 1 to 42 d of age. Broilers fed diets formulated with ULSBM had higher (P < 0.05) carcass yield vs. birds fed diets with SBM. Total breast yield was higher (P = 0.021) for birds fed diets containing LOSBM and ULSBM vs. SBM. Abdominal fat percentage was higher (P = 0.027) for broilers fed diets containing LOSBM vs. SBM. Diets formulated with LOSBM and ULSBM required approximately 45% less supplemental fat, and broilers fed these diets exhibited no adverse effects on growth performance and meat yields compared with broilers fed diets containing the conventional SBM.