Nutritional evaluation of soybean meals varying in oligosaccharide content

Three conventional soybean meals (CSBM) and five low-oligosaccharide soybea n meals (LOSBM) were evaluated. Meals were prepared by solvent-extracting f lakes from generic soybean lines and soybean lines genetically modified to contain varying oligosaccharide content. The mean raffinose, stachyose, and galactinol levels in the CSBM were 0.58, 3.23, and 0%, respectively. The m ean (range) raffinose, stachyose, and galactinol levels in the LOSBM were 0 .08 (0.03 to 0.17%), 0.42 (0.04 to 1.08%), and 0.104 (0 to 0.24%), respecti vely. The, crude fiber, fat, and ash contents of all SBM were similar, wher eas the CP and sucrose contents of the LOSBM were slightly higher than the CSBM. The effect of SBM type on digesta passage rate, dry matter digestibil ity, and TMEN was assessed in conventional and cecectomized roosters using a precision-fed rooster assay (8 x 2 factorial design). Quantitative collec tion of excreta for 4, 8, 12, 16, 20, 24, and 48 h postfeeding indicated li ttle or no effect of SBM type on digesta passage rate. The dry matter diges tibility and TMEN values for the SBM were lower for cecectomized roosters c ompared with conventional roosters (P < 0.05), and there was no significant SBM x bird type interaction. The mean TMEN values (kcal/kg DM) for the CSB M and LOSBM were 2,739 and 2,931, respectively, which was a difference of 7 % (P < 0.05). The two LOSBM with the lowest total raffinose, stachyose, and galactinol levels (0.07% and 0.25%) had average TMEN values that were 9.8% (P < 0.05) higher than their respective genetic controls. Digestibilities of raffinose and stachyose were much higher (P < 0.05) in conventional roos ters than in cecectomized roosters. The results of this study indicated tha t the TMEN of LOSBM was higher than that of CSBM.