Katia Cappelli

The dietary supplementation of olive oil by-products, including olive mill waste-water (OMWW) in animal diets, is a novel application that allows for their re-utilization and recycling and could potentially decrease the use of antibiotics, antimicrobial resistance risk in livestock species, and the occurrence of intestinal diseases. Salmonella serovar typhimurium is one of the most widespread intestinal pathogens in the world, causing enterocolitis in pigs. The aim of this study was to investigate the effect of an OMWW extract enriched in polyphenols (hydroxytyrosol and tyrosol) in the immune response of an intestinal porcine epithelial cell line (IPEC-J2) following S. typhimurium infection. Cells were pre-treated with OMWW-extract polyphenols (OMWW-EP, 0.35 and 1.4 µg) for 24 h and then infected with S. typhimurium for 1 h. We evaluated bacterial invasiveness and assayed IPEC-J2 gene expression with RT-qPCR and cytokine release with an ELISA test. The obtained results showed that OMWW-EP (1.4 µg) significantly reduced S. typhimurium invasiveness; 0.35 µg decreased the IPEC-J2 gene expression of IL1B, MYD88, DEFB1 and DEFB4A, while 1.4 µg down-regulated IL1B and DEFB4A and increased TGFB1. The cytokine content was unchanged in infected cells. This is the first study demonstrating the in vitro immunomodulatory and antimicrobial activity of OMWW extracts enriched in polyphenols, suggesting a protective role of OMWW polyphenols on the pig intestine and their potential application as feed supplements in farm animals such as pigs.

This study investigated the effect of environment, horse and type of different field standardised exercise tests (fSET) on incremental lactate concentration and recovery time in endurance horses. Forty-eight endurance horses underwent one or multiple fSET on a 700-m all-weather racetrack. The fSET comprised phase 1 canter at 19.5-21.5 km/h for 19 km (group N), or 37 km split by 20 minutes of rest (group E1) or 37 km (group E2), followed by phase 2 canter at 26-32.6 km/h and phase 3 at 27.7-42.8 km/h, for 1,400 m each for all groups. Blood lactates were recorded after each phase. Linear mixed models were built with blood lactate value and recovery time as dependent variables and horse and environment data, and type of fSET as fixed effect variables, with horse and horse × fSET group as random effects. Data from a total of 130 fSETs were considered; lactate values were 0.78-7.73 mmol/l (median 1.79 mmol/l) for phase 1, 1.70-10.68 mmol/l (median 3.89 mmol/l) for phase 2, and 3.7-20.86 mmol/l (median 8.74 mmol/l) for phase 3. Blood lactate values after phase 1 and phase 2 were significantly lower in group E1 (median 1.49 mmol/l; median 3.12 mmol/l) compared with group N (median 2.77 mmol/l; median 5.28 mmol/l; ) and group E2 (median 2.06 mmol/l; median 4.39 mmol/l; ). Blood lactate after phase 3 did not differ between groups. There were two medical and 19 minor musculoskeletal issues within 2 hours after the fSETs. Weather temperature affected blood lactate values after phase 1 and 2 (R = 0.62-0.63). Blood lactate after phase 1 (R = 0.93) and 2 (R = 0.66) affected values after phase 2 and 3, respectively. There was a considerable variation among horses and horse × fSET group random effects. Moreover, blood lactate values are affected by both weather conditions and by horse individual characteristics.