Soybean meal (SBM) is by far the most popular protein source used for feeding livestock. The objective of the present study was to test the efficacy of supplementation of b-mannanase in diets containing de-hulled or conventional hulled SBM (44% and 48%) in addition to evaluating the interactive effects of SBM and enzyme on growth performance, nutrient digestibility, fecal microflora, and noxious gas emission in weanling pigs. A total of 140 crossbred pigs with an initial weigh of about 6 kg were randomly allotted in a 2 × 2 factorial arrangement, with feed consisting of hulled or de-hulled SBM with or without 0.05% b-mannanase. The four treatments were replicated seven times with five pigs per pen.

In this study, pigs fed diets containing 0.05% b-mannanase had greater BW, ADG, G:F, and ADFI compared to pigs fed diets without b-mannanase, however, the differences were not statistically significant. Supplementing with b-mannanase had positive effects on nutrient digestibilities (dry matter, nitrogen, energy and phosphorus), on feed efficiency, and for reducing E. coli population in weanling pigs.