The effect of feeding Rhizopus oligosporus on growth performance, nutrient digestibility, blood profile, fecal microbiota, and fecal score in weanling pigs

Piglets were allocated to 1 of 3 treatments by body weight and sex, and fed different levels of 0%, 0.15%, and 0.30% of R. oligosporus 1.0 x 106 cfu/g, in a basal diet based on corn-soybean meal for 35 days. Piglets fed diets supplemented with R. oligosporus had higher average daily gain during days 15-35 and 1-35 (quadratic, P < 0.05). Feed conversion ratio during 1-35 days showed a significant improvement, as dietary R. oligosporus supplementation increased from 0.15% to 0.30% (linear, P < 0.05). Apparent total tract digestibility (ATTD) of crude protein (CP) was increased at 2 weeks, as dietary R. oligosporus supplementation increased significantly (linear and quadratic, P < 0.05), and ATTD of dry matter, CP, and energy were linearly increased at 5 weeks (P < 0.05). The serum IgG concentration was significantly increased in the R. oligosporus-fed groups (quadratic, P < 0.05). Fecal Lactobacillus counts were significantly increased quadratically and coliform bacteria counts were decreased linearly, as dietary R. oligosporus supplementation increased (P < 0.05). In conclusion, diets containing R. oligosporus may improve the growth performance, nutrient digestibility, IgG concentration, and intestinal environment in weanling pigs.