Influence of Nutritional Strategies on Performance, Gut Barrier Function and Microbiota Composition in Weaned Piglets

The restriction of antibiotics and therapeutic zinc oxide in piglet diets has increased challenges related to gut health and post-weaning performance. This study assessed the effects of a diet supplemented with organic acids and the probiotic <i>Clostridium butyricum</i> on intestinal integrity, fecal microbiota composition, and performance parameters in weaned piglets. Forty piglets were selected at weaning, and fecal samples were collected on day 0 and day 14 of supplementation. Gene expression of tight junction proteins (zonulin, occludin) and inflammatory markers (calprotectin, IFN-γ, TGF-β) was analyzed by PCR. Bacterial DNA quantification was used to evaluate microbiota changes. In addition, average daily gain (ADG), feed conversion ratio (FCR), and mortality were recorded across three feeding phases: CONTROL, TRANSITION, and 0M. No significant changes were found in tight junction protein expression post-weaning, but reductions in IFN-γ and TGF-β suggest improved immune modulation. Piglets in the TRANSITION and 0M groups showed higher ADG (CONTROL = 292.28 g/day; TRANSITION = 300.09 g/day; 0M = 307.45 g/day) and reduced mortality (CONTROL = 6.48%; TRANSITION = 5.10%; 0M = 5.08%) compared to CONTROL. These findings indicate that targeted dietary supplementation can support gut health and performance in weaned piglets, offering a promising alternative to medicated feed under current regulatory constraints. Further research is guaranteed to refine these strategies for broader application in sustainable pig production.