Dietary Organic Selenium Supplementation for Weaned Piglets Challenged with Deoxynivalenol

This study aimed to investigate the effects of dietary selenium (Se) supplementation levels on the apparent total tract digestibility (ATTD) of crude protein, crude fat, and crude ash, and cecal microbiota diversity and composition in nursery piglets challenged with deoxynivalenol (DON). Twenty-four weaned piglets were allocated to four dietary treatment groups (n = 6). The four treatment diets were as follows: (1) post-weaning diet containing 0.3 mg/kg of Se; (2) post-weaning diet without supplemental Se + 3 mg/kg DON; (3) post-weaning diet containing 0.3 mg/kg Se + 3 mg/kg DON; and (4) post-weaning diet containing 0.5 mg/kg Se + 3 mg/kg DON. The native Se levels in the feedstuffs were 0.03-0.06 mg/kg. The Se source was supplemented in the form of selenomethionine. The trial lasted 28 days, with fecal samples collected during the final 4 days for ATTD analysis of crude protein, crude fat, and crude ash. Upon trial completion, cecal digesta was sampled for microbial diversity and composition analysis. The results showed that piglets in the 0.5 mg/kg Se + DON group had a higher ATTD of crude fat than the 0 mg/kg Se + DON group and a greater ATTD of crude ash than the 0.3 mg/kg Se + DON group (p < 0.05). Additionally, the 0.5 mg/kg Se + DON group displayed increased Shannon and Chao 1 indices compared to the 0 mg/kg Se + DON group (p < 0.05). Microbial composition analysis revealed higher Firmicutes abundance in the 0.5 mg/kg Se + DON group than in the 0.3 mg/kg Se + DON group, along with reduced Euryarchaeota abundance relative to the 0 mg/kg Se + DON group (p < 0.05). The 0.5 mg/kg Se + DON group also had higher Selenomonadaceae abundance than the other groups (p < 0.05). Pearson correlation analysis indicated a negative correlation between Selenomonadaceae abundance and the ATTD of ash, whereas [Eubacterium]_coprostanoligenes_group abundance was positively correlated with the ATTD of ash (p < 0.10). Collectively, dietary Se supplementation at 0.5 mg/kg improved nutrient digestibility in DON-exposed nursery piglets, which was potentially associated with the modulation of cecal microbiota diversity and composition.