PS6-2. Olive Bioactives Mitigate Oxidative Stress in Weaned Piglets Exposed to a Social Stress Challenge

Oxidative stress is a physiological consequence of different challenges occurring in modern pig husbandry practices, impairing the performance and the physiological condition of the animals. Young piglets suffer from social stress when mixing with different counterparts early after weaning, among other challenges. In this sense, mechanisms mediated by the activation of antioxidant proteins [i.e., Glutathione peroxidase (GPx), Catalase (CAT) or Superoxide dismutase (SOD)] aiming to fight back against oxidative stress are well described. Olive bioactives exhibit great antioxidant and anti-inflammatory activities. The present study aimed to evaluate the potential of olive bioactives (OBE) supplementation in mitigating oxidative and inflammatory responses in young piglets subjected to a social stress challenge. A total of 180 mixed-sex piglets Pietrain x (Landrace x Large White) were used. At weaning (27.5d ± 2.16d), piglets were randomly assigned to three different treatments: i) control diet (CON); ii) control diet + social stress (SS); iii) control diet + OBE + SS (OBE+SS). The standardized OBE premixture contained at least 0.2% of polyphenols and at least 2.5% of triterpenes dosed at 2.5 kg/t. Piglets were socially stressed by mixing different pens of piglets within the same treatment for three consecutive days (day 25 to day 27 after weaning). Next, blood and fecal samples were collected for biological analyses from 12 piglets/treatment. Data was analyzed by One-Way Anova (GraphPad v10). For performance data, BW on day 21 was used as a covariate. Performance results showed that OBE tended to improve the BW of the animals after the SS challenge on day 28 (CON: 14.1kg, SS:13.9kg, OBE+SS:14.2kg; P = 0.1). The growth of the animals (from 21 to 28 days after weaning) followed a similar pattern (CON: 413.2g/d, SS:382.9g/d, OBE+SS: 415.9g/d; P = 0.1), while feed intake was similar among treatments (P > 0.05), with tendency for improving FCR (CON: 1.56, SS:1.62, OBE+SS: 1.49; P = 0.09) on the OBE+SS group compared to the SS group. Group OBE+SS had trend for improvement in CAT (CON: 50.20U/ml, SS: 29.33 U/ml, OBE+SS: 64.30 U/ml; P = 0.08) and SOD (CON: 2.97U/ml, SS:1.87 U/ml, OBE+SS: 2.70 U/ml; P = 0.06) activities in plasma, respectively, while GPx activity had no effect (P > 0.05). Finally, no difference in Calprotectin amongst treatment groups was observed (P > 0.05). In summary, these results suggest that the administration of OBE in weaned piglets contributed to control the side effects of a SS challenge by supporting their antioxidant capacity and sustaining their performance. This may be a good strategy to help swine producers in the development of new natural strategies to effectively increase piglet’s resilience against stressors present in intensive farms.