PSIX-25 - Feed and water deprivation at weaning and subsequent heat stress impacts serum and ileal markers of gastrointestinal integrity in nursery pigs

Abstract: Social and environmental stressors impact nursery pig performance and may be linked to gastrointestinal dysfunction. The current experiment was conducted to investigate the impact of feed and water deprivation on serum stress markers and ileal mucosal gene expression in nursery pigs. Mixed-sex pigs were allotted on the basis of IBW (7.0 kg ± 0.89) in a RCBD with treatments in a split-plot arrangement and consisting of the whole-plot factor of with or without a 24-h feed and water deprivation at weaning and the sub-plot factor of with or without a cyclic 3-d heat stress starting 27 d post-weaning. On 1, 27, and 30 d post-weaning one pig from each pen was selected, blood was collected for measurement of serum cortisol, corticotrophin releasing factor (CRF), and endotoxins, and an ileal mucosal scraping was taken and gene expression of claudin 1 (CL-1), occludin (OC), and zonula occludens 1 (ZO-1) were measured by RT PCR. There was an increase (P < 0.05) in serum CRF and endotoxins and a tendency for an increase (P = 0.09) in serum cortisol due to the deprivation 1 d post-weaning. Further, there was a tendency for an increase (P < 0.10) in serum endotoxins and CRF due to the deprivation at 27 and 30 d post-weaning, respectively. Gene expression of CL-1 tended to increase (P = 0.10), and OC decreased (P = 0.05) due to the deprivation 1 d post-weaning. Expression of the OC gene decreased (P < 0.05) due to the deprivation 27 d post-weaning and OC and ZO-1 gene expression tended to decrease (P = 0.07) due to the heat stress 30 d post-weaning. These results show that post-weaning stress events alter serum stress markers and impact intestinal barrier function.