Effects of Dietary Vitamin E and Selenium on Growth Performance and Immune Response of Nursery Pigs Following an Immune Challenge

Antioxidants, such as Se and vitamin E, have been reported, in some instances, to improve growth performance in nursery pigs, but reports on the effect of these nutrients on immune response are limited. To study the effects of Se and vitamin E on growth performance and immune response, 280 crossbred pigs (5.8 kg BW) were used in a 36-d experiment. From d 0-7, all pigs were fed a common diet (0.15 mg/kg Se, 16 IU/kg vitamin E). On d 7, pens (10 pigs/pen) were randomly allotted to 1 of 4 dietary treatments arranged in a 2 x 2 factorial (7 reps/trt) consisting of the combination of two concentrations of Se (0.15 vs. 0.30 mg/kg) and vitamin E (16 vs 32 IU/kg). Diets were based on corn and soybean meal and the diets were mixed by adding Se (Sel-Plex^® 600, Alltech, Inc ) and/or vitamin E (Lutavit^® E 50, BASF ) to a basal diet. Pigs and feeders were weighed weekly to determine ADG, ADFI and G:F. On d 21, 4 pigs from each pen were challenged with LPS E.coli O111:B4 (25 µg of LPS/kg BW). Body wt, rectal temperature (RT) and blood was collected for determination of cytokines at h 0, and 3 and 6 h post-injection. Data were analyzed as completely randomized design with the main effects of Se, vitamin E, and their interaction tested. There were no (P > 0.10) Se by vitamin E interactions for any response criteria. There were no differences (P > 0.10) in growth performance for d 7-21. However, for d 21-36, ADG and G:F were improved (P < 0.02) for pigs fed increasing Se. For the entire period (d 7-36), increasing Se improved (P < 0.04) G:F, but did not affect (P > 0.10) ADG or ADFI. Following LPS challenge, RT, TNF-α, and IL-1 were increased (P < 0.05) at 3 h post-injection, but no differences (P > 0.10) among treatments were noted. However, growth performance (ADG, G:F) was increased (P < 0.05) and TNF-α concentrations were reduced (P < 0.10) when pigs were fed the combination of high Se (0.30 mg/kg)/vitamin E (32 IU/kg) compared to those fed the low concentrations (0.15 mg/kg; 16 IU/kg). These data suggest that increasing Se (up to 0.30 mg/kg) increased growth performance in nursery pigs, but increasing vitamin E had little effect. Furthermore, increasing Se or vitamin E had little effect on pro-inflammatory cytokine production.