364 Impact of porcine reproductive and respiratory syndrome virus challenge and deoxynivalenol on intestinal integrity and nutrient transport

Abstract

Abstract Porcine reproductive and respiratory syndrome (PRRS) virus infections and mycotoxin contaminated feedstuffs are two common issues facing the pork industry as both act, independently, to antagonize pig intestinal function, growth performance, and health. However, the combined impact of PRRS and mycotoxin exposure on pig intestinal health and function has not been investigated. Therefore, the objective of this experiment was to examine the impact of the mycotoxin deoxynivalenol (DON) on the intestinal integrity and function of PRRS infected pigs, employing an ex vivo model. Jejunum samples were collected from PRRS naïve (control; n = 6) and 21 day post inoculated PRRS virus infected (n = 8) gilts (10 weeks of age). In duplicate, explants were mounted into modified Ussing Chambers and incubated with or without 25 mM DON for 45 minutes prior to assessment of transepithelial resistance (TER), mucosal to serosal macromolecule (FD4) flux, and active glucose and glutamine transport. Data were analyzed using the mixed model procedure of SAS and a split plot design to examine the fixed effects of PRRS, DON, and their interaction. There were no PRRS by DON interactions for any ex vivo parameters assessed. Irrespective of DON, PRRS jejunum segments had decreased TERs (57%, P < 0.001), increased FD4 flux (P = 0.005), and tended to have increased active glucose transport (P = 0.093) compared with uninfected controls. Irrespective of PRRS status, DON increased FD4 flux (113%, P = 0.013), and tended to increase active glucose transport (P = 0.088) compared with jejunal explants not treated with DON. However, TERs and active glutamine transport did not differ due to DON treatment. Taken together, these data highlight the impacts that viral health challenge and mycotoxin contamination have on aspects of intestinal integrity and function. However, it does not appear that PRRS challenged pigs are more sensitive to the effects of DON than their healthy counterparts.