Effects of Vitamins E and D on Performance and Antioxidant Enzymes in Nursery Pigs.

Pigs are stressed at weaning due to co-mingling, change of diet, environment, and perhaps disease. We hypothesized that adding vitamins E and D to the pig’s intake at weaning, would improve their antioxidant response to stress and thus improve overall health. The pig’s cellular antioxidant system includes the enzymes superoxide dismutase (SOD) and glutathione peroxide (GPx), made endogenously, which can be up or down regulated in response to need. Vitamins, however, must be supplied exogenously. We had previously reported (Gebhardt et al., 2015) that injections of vitamin E, D, and A to sows increased red blood cell (RBC) GPx in their offspring. The present experiment was conducted to study the influence of vitamins E and D supplementation in water on growth, feed intake, and on RBC SOD and GPx activities. At 23 ± 3 d of age, 150 PIC 327 sired pigs were weaned and allotted by sex, litter and weight into 30 pens of 5 pigs each. Pens were randomized within a single nursery room. Pigs from both treatments were fed commercial nursery diets which met or exceeded the NRC (NRC, 2012) nutrient requirements for 35 d. Treatment pigs received Emcelle^® E-D₃ Liquid (Stuart Products, Inc., Bedford, TX) through the water system to provide 120 IU vitamin E and 7,200 IU vitamin D per gallon drinking water. Total daily water consumption was similar between the control and treatment groups. Control pigs received water with no added vitamins. Pigs were weighed and pen feed intake calculated at 11, 20, and 31 d post-weaning. Twelve randomly selected pigs from each treatment were bled at 31 d post-weaning for determination of RBC SOD and GPx by commercially available kits. There was no treatment effect on overall ADG (0.46 vs. 0.45 kg/d; P = 0.52), ADFI (0.62 vs. 0.62 kg/d; P = 0.98), or G:F (0.75 vs. 0.73; P = 0.16) in control vs. vitamin treated pigs, respectively. However, SOD (362.86 vs. 324.17 U/ml; P = 0.005) and GPx activities (10,525 vs. 8105 nmol min^-1 ml^-1; P = 0.0002) in control vs. vitamin treated, respectively, were reduced in the pigs receiving the vitamins in their drinking water. In this study while there was no improvement in production parameters, antioxidant enzyme activities were reduced hypothetically due to decreased need because of elevated vitamins provided in the drinking water.