Effects of different delivery forms of the novel Bacillus subtilis strain 87Y on redox status and liver function in peri-weaning piglets

Introduction Weaning is a critical stage in piglet rearing, and dietary strategies are needed to support metabolic balance and oxidative resilience during the peri-weaning period. Material and Methods A total of 384 Yorkshire × Danish Landrace piglets at 28 days old were allocated to four groups: positive controls with feed additives including ZnO (PC), negative controls without additives (NC), NC + 8% fermented rapeseed meal (FR) and NC + 0.1% Bacillus subtilis 87Y (BS). Blood was collected from 24 males (one per replicate) for redox and biochemical analyses, and liver and small intestine samples were collected post mortem for oxidative marker assessment and histopathology. Results Compared with NC, FR and BS supplementation increased antioxidant defence (catalase, superoxide dismutase and glutathione) and reduced lipid peroxidation markers (malondialdehyde and lipid hydroperoxides) in plasma and tissues; changes were accompanied by favourable shifts in selected lipid metabolism indices and liver enzyme activities. The pure probiotic form of Bacillus subtilis was not inferior to the fermented matrix and, for selected parameters, produced an effect stronger than that observed in the PC diet. Conclusion Bacillus subtilis 87Y improved redox status and supported liver function in peri-weaning piglets, with efficacy largely independent of the delivery form, indicating potential as a feed additive.