Apparent metabolizable energy and apparent ileal amino acid digestibility of low and ultra-low oligosaccharide soybean meals fed to broiler chickens

Four experiments were conducted using 1,992 Ross x Ross 708 male broilers to determine AME(n) and apparent heal amino acid digestibility (AIAAD) of low-oligosaccharide (LOSBM), ultra-low oligosaccharide (ULSBM), and control soybean meal (CSBM) fed to broilers from 20 to 31 d of age. An AME(n) assay was conducted in experiments 1 and 2, whereas AIAAD was determined in experiments 3 and 4. Chicks were randomly assigned to 3, 4, 2, or 3 dietary treatments, respectively, for experiments 1, 2, 3, or 4. The additional treatment in experiments 2 and 4 was to evaluate ULSBM. In the AME(n) assays, treatments were fed from 20 to 29 d of age and a 48-h excreta collection period was conducted from 27 to 29 d of age. Treatment 1 consisted of a basal diet and treatments 2; 3, and 4 consisted of 70% of the basal diet plus 30% CSBM; LOSBM, or ULSBM, respectively. The difference method was used to determine AME(n) utilizing an N correction factor to account for N retention. To determine AIAAD, broilers were fed semi-purified diets with CSBM, LOSBM, or ULSBM as the sole source of amino acids (AA) from 26 to 31 d of age with digesta collection occurring at 31 d of age. In experiment 1, LOSBM had 194 kcal/kg more AME(n) compared with CSBM (P = 0.011). Apparent MEn value of LOSBM was 141 and 134 kcal/kg higher (P = 0.012) compared with CSBM and ULSBM, respectively; in experiment 2. Digestible Lys, Met, Ile, and Val concentrations were higher (P < 0.001) for LOSBM vs. CSBM in experiment 3 even though digestibility coefficients were lower (P < 0.001) for LOSBM. In experiment 4; higher (P < 0.001) concentrations of digestible Met, Lys, Thr, and Ile were observed for ULSBM and LOSBM compared with CSBM. In conclusion, genetically selected soybean meals with reduced stachyose and raffinose concentrations had higher AME(n) and AIAAD values compared with CSBM.