Effects of a Natural Polyphenolic Product from Olive Mill Wastewater on Oxidative Stress and Post-Weaning Diarrhea in Piglets

The present study aimed to investigate the effects of a commercial phytogenic feed additive (PFA) on the prevention of post-weaning diarrhea and oxidative stress in piglets. The concentrations of thiobarbituric acid reactive substances (TBARS) and protein carbonyls (CARBS) were investigated as biomarkers for oxidative damage, as were the health and performance parameters of weaned piglets. In total, 100 weaned piglets were divided into two groups: a control group (T1), which was fed regular weaning feed; an experimental group (T2), which was fed regular weaning feed supplemented with a phenolic feed additive (PFA) for 3 weeks. The TBARS and CARBS concentrations in plasma samples from 20 piglets per group were measured at 45 and 65 days of age. Fecal samples were collected from 24 weaned piglets per group using FTA ELUTE cards. Diarrhea score, body weight (BW) at weaning, and average daily weight gain (ADWG) were recorded. The TBARS (p < 0.001) and CARBS (p = 0.001) concentrations were significantly higher in the T1 group compared to those in the T2 group. The lowest diarrhea score was noted in the T2 group for the age groups of 45 (p < 0.001) and 65 days (p = 0.008). In conclusion, the use of a phenolic PFA in the current study had beneficial antioxidative and antimicrobial effects on weaned piglets, which improved their health and growth performance.