Fecal concentrations of gut microbial metabolites in sows d18 of lactation. (A) acetic acid, (B) propionic acid, (C) isobutyric acid, (D) butyric acid, (E) isovaleric acid, (F) valeric acid, (G) total short-chain fatty acids (SCFA). Data are presented as means ± SD (n = 7). Values with different lowercase letters (a, b) indicate a significant effect of treatment (P < 0.05). CON group, sows fed diets without IMO; IMO group, sows fed diets containing 5.0 g/kg IMO; IMOS group, sows fed diets containing 5.0 g/kg IMO plus 0.2 g/kg Bacillus subtilis; IMOL group, sows fed diets containing 5.0 g/kg IMO plus 0.2 g/kg Bacillus licheniformis; IMOSL group, sows fed diets containing 5.0 g/kg IMO plus 0.2 g/kg B. subtilis and 0.2 g/kg B. licheniformis.