The effect of deoxynivalenol-contaminated corn and an immune-modulating feed additive on growth performance and immune response of nursery pigs fed corn- and soybean meal-based diets

Abstract

Abstract One hundred eighty newly weaned pigs (21 days of age; 6.9 ± 0.2 kg BW) were used to determine the effects of deoxynivalenol- (DON) contaminated corn and an immune-modulating feed additive on growth performance and immune response of nursery pigs fed corn- and soybean meal-based diets. Pens were randomly assigned to one of five diets: a high-complexity (HC; containing animal protein sources) or one of four low-complexity diets (LC; containing soybean meal as the main protein source) arranged in a 2 × 2 factorial with low (lDON; average 1.4 ppm) or high (hDON; average 3.5 ppm) DON and with or without a feed additive (2 g/kg in complete feed; n = 6 pens per treatment) provided in a three-phase feeding program. On day 7, small intestinal histomorphology was assessed in two pigs per pen. On days 8 and 25, two pigs per pen were immunized with ovalbumin (OVA). Blood was collected on days 8, 25, and 38 for determination of OVA-specific IgG. There were no corn type by feed additive interactions or feed additive effects for growth performance. The ADG, ADFI, and G:F in phase I were not different for pigs fed hDON vs. lDON, but were less than those fed the HC diet (contrasts; P < 0.05). Over the entire nursery period, ADG and ADFI were less for pigs fed hDON vs. those fed lDON (407 vs. 484 g and 651 vs. 769 g, respectively; P < 0.05), ADG was less for pigs fed hDON vs. HC (496 g; P < 0.05), and pigs fed lDON had ADG and ADFI not different from those fed the HC diet. Pigs fed hDON had lower final BW than those fed lDON (24.6 vs. 27.6 kg; P < 0.01) and tended to have lower final BW than pigs fed the HC diet (27.3 kg; contrast; P = 0.052); final BW was not different between pigs fed lDON and HC diets. Jejunal villus heights were shorter for pigs fed hDON and lDON compared to pigs fed HC (438 and 466 vs. 538 µm; contrasts; P < 0.05 and P = 0.090, respectively) and the villus:crypt ratio tended to be less for pigs fed hDON vs. those fed HC (1.87 vs. 2.22; contrast; P = 0.091). On day 38, plasma OVA-specific IgG 1 tended to be less for pigs fed hDON compared to HC (contrast; P = 0.075) and OVA-specific total IgG were less for pigs fed LC diets without the feed additive vs. HC (P < 0.05). Therefore, high DON (~3.5 ppm) in LC nursery diets interfered with compensatory growth and the humoral immune response. The feed additive did not rescue growth performance, regardless of DON contamination level in LC nursery diets.