The administration of diets contaminated with low to intermediate doses of deoxynivalenol and supplemented with antioxidants and binding agents slightly affects the growth, antioxidant status and vaccine response in weanling pigs

Abstract

This study aimed to evaluate the impact of grading levels of deoxynivalenol (DON) in the diet of weaned pigs, as well as the effects of a supplementation with antioxidants (AOX), hydrated sodium calcium aluminosilicates (HSCAS) and their combination on the growth, antioxidant status, immune and vaccine response against the porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus 2 (PCV2). At weaning, 336 piglets were allocated to six dietary treatments according to a randomized complete block design. Treatments were as follows: basal diet (CTRL); basal diet containing DON at 1.2 mg/kg (DON1.2); basal diet containing DON at 2.4 mg/kg (DON2.4); DON2.4 diet + a mix of AOX which included vitamins A and E at 20,000 IU and 200 IU/kg feed respectively, selenized yeast at 0.3 mg/kg and a grape seed extracts at 100 mg/kg feed (DON2.4+AOX); DON2.4 diet + modified HSCAS at 1 g/kg (DON2.4+HSCAS); DON2.4+AOX+HSCAS. Pigs were vaccinated against PRRSV and PCV2 at 7 d; at 0, 14 and 35 d growth performance were recorded, and blood samples were collected in order to evaluate the oxidative status, inflammatory blood markers, lymphocyte blastogenic response and vaccine antibody response. Increasing intake of DON resulted in a quadratic effect at 35 d in the lymphocyte proliferative response to Concanavalin A and PCV2 as well as in the anti-PRRSV antibody response, whereas the catalase activity decreased in DON2.4 pigs compared to the CTRL and DON1.2 groups (P ≤ 0.05). Compared to the DON2.4 diet, the AOX supplementation slightly reduced G:F ratio (P = 0.026) and increased the ferric reducing ability of plasma as well as α-tocopherol concentration (P < 0.05), whereas the association AOX+HSCAS increased the anti-PRRSV IgG (P < 0.05). Furthermore, the HSCAS supplement reduced haptoglobin levels in serum at 14 d compared to the DON2.4 group; however, its concentration decreased in all the experimental treatments from 14 d to 35 d and particularly in the DON2.4+AOX pigs, whereas a different trend was evidenced in the DON2.4+HSCAS group, where over the same period haptoglobin concentration increased (P < 0.05). Overall, our results show that the addition of AOX and HSCAS in the diet may alleviate the negative effects due to DON contamination on the antioxidant status and immune response of vaccinated weanling pigs.