Effects of dietary fish oil and alpha-tocopherol supplementation on selected blood parameters and fatty acid profiles in mares and their foals.
Authors: Danyer Erdem, Bilal Tanay
Journal: Journal of animal physiology and animal nutrition
Summary
# Editorial Summary Supplementing pregnant mares with fish oil (40 ml/day) during the final 65 days of gestation, particularly when combined with synthetic alpha-tocopherol (2,500 IU/day), significantly elevated vitamin E concentrations in both colostrum and milk, with the combined supplement group achieving colostrum levels nearly double those receiving fish oil alone (2.56 versus 1.33 µg/ml). Whilst the vitamin E supplementation successfully transferred to foal serum, the fish oil component failed to meaningfully increase circulating eicosapentaenoic acid and docosahexaenoic acid concentrations in newborns, suggesting limited bioavailability or transfer of these omega-3 fatty acids across the placenta and into milk. Interestingly, foals from mares receiving fish oil alone showed elevated white blood cell counts by day five post-partum (11.33 × 10⁹/l) compared to supplemented and control groups, though the clinical significance of this remains unclear. For equine practitioners, this indicates that combining fish oil with vitamin E is worthwhile for maximising passive immunity transfer through enhanced colostrum quality, but fish oil supplementation alone offers marginal benefits for foetal omega-3 status and warrants further investigation before routine recommendation.
Read the full abstract on PubMed
Practical Takeaways
- •Adding synthetic alpha-tocopherol (vitamin E) to fish oil supplementation in late pregnancy effectively increases vitamin E transfer to colostrum and milk, potentially improving passive immunity in foals
- •Fish oil alone did not translate into increased omega-3 fatty acids in foal blood serum, suggesting absorption or bioavailability limitations that warrant further investigation before routine supplementation
- •Late-pregnancy supplementation strategies should consider combining vitamin E with omega-3 sources, as vitamin E supplementation appears beneficial while fish oil benefits remain unproven in this population
Key Findings
- •Alpha-tocopherol supplementation (2,500 IU/day) significantly increased alpha-tocopherol concentrations in colostrum (2.56 vs 1.33 µg/ml) and milk (1.36 vs 0.72 µg/ml) compared to fish oil alone (p < 0.05)
- •Foal WBCs were significantly higher in the fish oil only group (11.33 × 10⁹/l) compared to fish oil + alpha-tocopherol (9.18 × 10⁹/l) and control (7.26 × 10⁹/l) groups at day 5 post-partum (p < 0.05)
- •Fish oil supplementation (40 ml/day) did not significantly increase serum eicosapentaenoic acid and docosahexaenoic acid concentrations in foals
- •Maternal dietary supplementation had no significant effect on mare haematology or biochemistry during late pregnancy