Journal of animal science2021; 99(7); skab177; doi: 10.1093/jas/skab177

Dietary omega-3 fatty acid supplementation does not impair vitamin E status or promote lipid peroxidation in growing horses.

Abstract: Omega-3 (n-3; ω-3) fatty acids (FA) are often included in the diet for their potential health benefits. However, because oxidative potential is increased with the degree of unsaturation in vitro, polyunsaturated FA such as eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) may be at increased risk of lipid peroxidation. We aimed to determine the effects of dietary n-3 FA supplementation on antioxidant status and lipid peroxidation in yearling horses. Quarter Horses (mean ± SEM; 14.6 ± 0.2 mo) were randomly assigned to receive no n-3 FA supplementation (CON; n = 6) or 60 mg n-3/kg body weight from milled flaxseed (FLAX; n = 6) or encapsulated fish oil (FISH; n = 6). All horses received a basal diet of mixed grain concentrate fed individually at 1.5% body weight (dry matter basis) and ad libitum bahiagrass pasture forage. Blood samples were obtained before and after 70 d of supplementation to evaluate vitamin E, selenium, lipids, antioxidant status, and oxidative stress. Data were analyzed using a mixed model ANOVA with repeated measures. Supplementation with n-3 FA did not reduce serum vitamin E or Se and, in fact, elevated (P ≤ 0.0003) vitamin E status in FISH horses. At day 70, serum triglycerides were lower in FISH and FLAX horses than CON horses (P ≤ 0.02) and F2-isoprostanes were lower in FISH than CON horses (P = 0.0002). Dietary n-3 FA had no effect on cholesterol, reduced and oxidized glutathione, glutathione peroxidase, and thiobarbituric acid-reactive substances. In growing horses fed to meet their vitamin E requirements, supplementation with 60 mg n-3/kg body weight did not negatively affect vitamin E status or promote lipid peroxidation. Elevated vitamin E status in horses fed FISH, coupled with lower serum F2-isoprostanes, further suggest that the longer-chain, highly unsaturated n-3 FA, EPA and DHA, may actually attenuate lipid peroxidation.
Publication Date: 2021-07-07 PubMed ID: 34228797PubMed Central: PMC8259830DOI: 10.1093/jas/skab177Google Scholar: Lookup
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  • Journal Article
  • Randomized Controlled Trial
  • Veterinary


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The research paper discusses a study which investigated the effects of omega-3 fatty acid supplementation on antioxidant status and lipid peroxidation in growing horses. The findings suggest no negative impacts on either vitamin E status or lipid peroxidation from the implementation of such supplementation.

Introduction and Objective of the Study

  • The study was primarily conducted to understand the effects of omega-3 fatty acid supplementation on antioxidant status and lipid peroxidation in horses.
  • Omega-3 fatty acids are known for their health benefits, but there exists a potential concern regarding lipid peroxidation due to the increased oxidative potential with the degree of unsaturation.
  • The two specific Omega-3 fatty acids investigated were eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).


  • The research was conducted on yearling Quarter Horses, randomly divided into three groups: horses with no omega-3 fatty acid supplementation (CON), horses supplemented with omega-3s via flaxseed (FLAX), and horses receiving their omega-3s through fish oil (FISH).
  • All the horses were fed a basal diet of mixed grain concentrate and ad libitum bahiagrass pasture forage.
  • The two supplemented groups received 60 mg of omega-3 per kg of their body weight.
  • The effects of supplementation were evaluated by taking blood samples before and after 70 days of supplementation, which were then checked for vitamin E, selenium, lipids, antioxidant status, and oxidative stress.

Research Findings

  • The results revealed that omega-3 fatty acid supplementation did not have adverse effects on the serum levels of vitamin E or selenium. Instead, it elevated the vitamin E status in horses receiving supplements through fish oil (FISH group).
  • After 70 days, serum triglycerides were found to be lower in FISH and FLAX horses compared to the CON group, while F2-isoprostanes (a type of compound that indicates oxidative stress) were notably lower in the FISH group.
  • No substantial effects on cholesterol, reduced and oxidized glutathione, glutathione peroxidase, and thiobarbituric acid-reactive substances were recorded due to omega-3 fatty acid supplementation.
  • The evidence from the study suggests that supplementation with omega-3 fatty acids does not promote lipid peroxidation or impair the horses’ vitamin E status, but may actually attenuate lipid peroxidation, particularly with EPA and DHA.

Cite This Article

White-Springer SH, Vineyard KR, Kivipelto J, Warren LK. (2021). Dietary omega-3 fatty acid supplementation does not impair vitamin E status or promote lipid peroxidation in growing horses. J Anim Sci, 99(7), skab177.


ISSN: 1525-3163
NlmUniqueID: 8003002
Country: United States
Language: English
Volume: 99
Issue: 7
PII: skab177

Researcher Affiliations

White-Springer, Sarah H
  • Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA.
Vineyard, Kelly R
  • Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA.
Kivipelto, Jan
  • Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA.
Warren, Lori K
  • Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA.

MeSH Terms

  • Animals
  • Dietary Supplements
  • Fatty Acids, Omega-3
  • Fish Oils
  • Horses
  • Lipid Peroxidation
  • Vitamin E

Grant Funding

  • #00057680 / Florida Pari-mutuel Wagering Trust Fund Research


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