PSV-17 - Effect of replacing antibiotic growth promoters with a tributyrin in pre-starter diets on growth performance and gut health of weaned pigs

Abstract: An experiment was conducted to evaluate the effects of including a trybutirin (esterfied butyrate) as an alternative to antibiotic growth promoters (AGPs) in weaned piglet diets on growth performance and gut health parameters. Ninety-six 21-day-old piglets (PIC410® x Hypor®), with an initial body weight of 5.9 kg, were assigned to three dietary treatments in a randomized block design. Piglets were housed in groups of four and were randomly allotted to one of the following treatments: (1) a negative control diet (NC) without AGP, organic acids, or zinc oxide; (2) a positive control diet (PC) consisting of the NC diet supplemented with Avilamycin (0.3 kg/ton) as an AGP; and (3) a diet containing the NC supplemented with tributyrin (2 kg/ton) (NC+B). Diets were fed ad libitum over a 14-day period, during which fecal scores were recorded daily. Fecal samples were collected on days 0, 7, and 14 to analyze coliform and E. coli counts. Pigs were weighted and at the end of the experimental period growth performance was calculated. One piglet from each pen was euthanized for tissue and mucosal sampling from the jejunum and ileum to assess intestinal morphology and gene expression of interleukins (IL-10, TNF-α, IL-1β, IL-6) and tight junction proteins, including claudin (CLA) and zonula occludens (ZO). Results showed no significant differences (P >0.05) in growth performance among the dietary treatments. However, pigs fed the NC+B diet had significantly lower fecal scores (1.85) compared to those on the PC and NC diets (2.02 and 2.53, respectively; P< 0.05). Additionally, pigs fed the NC+B diet exhibited increased villus height (275 μm) and a higher villus height-to-crypt depth (VH:CD) ratio (1.46) in the ileum compared to those on the NC diet (247 μm and 1.12, respectively; P< 0.05). In addition, IL-6 and TNF-α expression in the ileum was reduced in the NC+B group compared to NC and PC groups (ΔCT IL-6: 9.5 vs. 11.4 and 11.8; ΔCT TNF-α: 1.4 vs. 3.5 and 3.1, respectively; P< 0.05). In contrast, TNF-α expression in jejune was greater (P< 0.05) in pigs on the NC+B diet compared to those on the NC and PC diets (7.0 vs. 3.2 and 2.8, respectively). No significant effects of dietary treatment were observed on CLA and ZO gene expression or the excretion of coliforms and E. coli throughout the experiment. In conclusion, the inclusion of tributyrin (2 kg/ton) in pre-starter diets did not impact growth performance but improved fecal consistency, enhanced intestinal morphology, and reduced the expression of proinflammatory interleukins in the ileum, suggesting a potential benefit for gut health in weaned piglets.