Feeding nursery pigs diets containing peroxidized soybean oil has minimal effects on oxidative status but dramatically reduces serum vitamin E concentrations

Authors: WILSON, VICTORIA - Iowa State University; Kerr, Brian

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2025
Publication Date: 3/12/2025
Citation: Wilson, V.C., Kerr, B.J. 2025. Feeding nursery pigs diets containing peroxidized soybean oil has minimal effects on oxidative status but dramatically reduces serum vitamin E concentrations. Journal of Animal Science. 103. https://doi.org/10.1093/jas/skaf016.
DOI: https://doi.org/10.1093/jas/skaf016

Interpretive Summary: Pigs can be exposed to a variety of nutritional stressors that can affect their well-being and productivity. One stressor of concern includes organic compounds named lipids that have been damaged (peroxidized) by excessive heating. An experiment was conducted to determine the effect of including peroxidized soybean oil in diets fed to growing pigs on performance and markers of oxidative stress. The data showed that adding soybean oil that had been peroxidized resulted in a dramatic reduction in animal performance, but had limited effects on measures of oxidative stress in the blood. The data did, however, show that blood levels of vitamin E were drastically reduced suggesting it may be preventing oxidative stress to occur. This information is important for nutritionists at universities, feed companies, and pig production facilities indicating the negative impacts of feeding diets containing peroxidized soybean oil on pig performance and blood levels of vitamin E.

Technical Abstract: A subgroup of pigs from two experiments (EXP) were selected to evaluate the impact of pigs fed diets containing peroxidized soybean oil (SO) on plasma-based measures of oxidative stress and vitamin E. Pigs were fed diets containing SO that was either unprocessed (23 °C; peroxide value of 3 meq/kg and an anisidine value 4) or thermally processed at 135 °C for 42 h (peroxide value of 30 meq/kg and an anisidine of 501). The corn-soybean meal-based diets contained either 10% SO (EXP 1) or 8% SO (EXP 2). Pigs were fed the experimental diets for 22 d (EXP 1, 13.5 to 24.0 kg, 2 pigs/pen) or 27 d (EXP 2, 21.3 to 37.5 kg, 1 pig/pen), each with 10 replications per dietary treatment. Pigs fed diets containing the peroxidized SO had reduced ADG, ADFI, and GF compared to pigs fed diets containing the unheated SO (P = 0.01). Pigs fed diets containing peroxidized SO had increased plasma concentrations of F2-isoprostanes and reactive oxygen metabolites compared to pigs fed diets containing unheated SO (P = 0.01). In contrast, plasma thiobarbituric acid reactive substances concentrations tended to decrease in pigs fed diets containing peroxidized SO compared to pigs fed diets containing unheated SO (P = 0.10). There was no apparent effect of pigs consuming diets containing peroxidized SO on plasma antioxidant adsorbent capacity or an oxidative stress index (P = 0.19). Pigs fed diets containing peroxidized SO resulted in a reduction in plasma vitamin E compared to pigs fed diets containing unheated SO (P = 0.01). Results indicate that adding soybean oil that has been thermally processed thereby containing high concentrations of aldehydes resulted in inconsistent changes of markers of oxidative stress, but dramatically reduced plasma vitamin E concentrations.