Evaluation of tannin extracts, leonardite and tributyrin supplementation on diarrhoea incidence and gut microbiota of weaned piglets

In this study, we evaluated the effect of Quebracho and Chestnut tannins, leonardite and tributyrin supplementation on intestinal health and performance in weaned piglets. One hundred sixty-eight piglets (Landrace × Large White) weaned at 28±2 days were randomly allotted in two experimental groups (6 pens/group, 14 piglets/pen). Groups were fed basal control diet (CTRL) and treatment diet (MIX) supplemented with 0.75% tannin extract, 0.25% leonardite and 0.20% tributyrin for 28 days. Zootechnical performance and diarrhoea incidence trough the faecal score (0-3; considering diarrhoea = 2) were recorded. At 0 d and at 28 d faecal samples were obtained from four piglets/pen for microbiological, chemical analysis and V3-V4 region amplification sequencing. At 28 days, two piglets/pen blood were sampled to evaluate serum metabolic profile.After 28 days, MIX revealed reduced diarrhoea incidence and lower faecal score compared to CTRL group (p < 0.05). In addition, MIX highlighted higher lactobacilli:coliform ratio and increased abundance of Prevotella and Fibrobacter genera (p < 0.01) compared to CTRL. Serum metabolic profile showed a decreased level of low-density lipoproteins in treated group (p < 0.05). In conclusion, the combination of tannin extract, leonardite and tributyrin could decrease diarrhoea incidence and improve gut health also through microbiota modulation.