TARGETING GUT INFLAMMATION IN PIGS WITH THE USE OF OLIVE FRUIT BIOACTIVES POSITIVELY INFLUENCES PIG PERFORMANCE

Prolonged inflammation derived from standard farming procedures drives animals to cytokine-induced anorexia accompanied to a negative energy balance, resulting in reduced animal performance. Previous work showed that the addition of olive fruit bioactives (OFB) in feed was able to reduce inflammation and prevent gut integrity side-effects on a model of LPS-challenged piglets. The present work was designed to evaluate the potential benefits of a new prototype based on standardized OFB and to test pig performance responses when added in transition diets. Anti-inflammatory activity was determined by gene expression analysis of IL-1β and iNOS on LPS-stimulated Raw264.7 macrophages. Benefits over the intestinal barrier were determined on an IPEC-J2 cell model by transepithelial resistance (TEER) measurement after 24h incubation with OFB. Finally, 192 21d-old weaned piglets ((LDxLW)x Pietrain) were blocked according to their initial body weight (BW), heavy and light, and distributed in pens (eight animals/pen) among three different dietary treatments: i) non-medicated diets in the pre-starter (weaning to 14d) and starter (15 to 42d) stages (C-), ii) pre-starter diet containing amoxicillin 300ppm and ZnO 2500ppm and starter diet with 300ppm of amoxicillin (AM), iii) C- diets with 500ppm of OFB added (OFB). BW and feed disappearance were recorded weekly. Performance data were analysed as a RCBD using a mixed-effect model with repeated measures. TEER and gene expression data were analysed using a mixed model. Statistical analyses were performed with SAS v.9.4. Increase in the relative expression of inflammatory markers after macrophages stimulation was significantly (P<0.01) reduced by OFB pre-incubation. Addition of OFB to IPEC-J2 cells resulted in larger relative TEER values (P<0.01). Final BW improved in AM and OFB groups vs C- in heavy pigs (P<0.05). In summary, the tested OFB prototype may improve performance of pigs fed with non-medicated diets through lowering inflammation and improving gut barrier function.