Vitamin E requirements of adult Standardbred horses evaluated by tissue depletion and repletion.

This research article investigates the vitamin E requirements in adult Standardbred horses by analyzing tissue depletion and repletion. The study focused on dietary adjustments related to vitamin E and its impact on the horse’s health and determined that optimal dietary intake of vitamin E is between 600 and 1800 mg per day for these horses.

Research Methodology

• The study involved Standardbred horses who were fed a diet low in vitamin E for eight months. This was done to establish a baseline and exclude any effect from other dietary components.
• Following an initial depletion period of two and a half months, the horses were grouped into different cohorts according to the dosage of DL alpha-tocopheryl acetate (a form of vitamin E) that they received on a daily basis.
• The control group received no supplement, while other groups received 200, 600, 1800, and 5400 mg respectively.
• The researchers conducted a supplemental study followed by a secondary depletion period, which allowed them to observe the effects of supplementation and depletion of vitamin E.

Analysis and Findings

• The content of Vitamin E and its individual natural tocopherol isomers and tocotrienol isomers in the horses’ feed and tissue were measured using high-performance liquid chromatography with fluorescent detection.
• The amount of total lipid in the serum remained constant throughout the study, hence the serum vitamin E levels were measured relative to grams of serum lipid.
• The conclusion drawn was that the levels of vitamin E in the serum, liver, skeletal muscle, and fat accurately reflected the amounts of vitamin E given as supplements.
• Despite the varying occurrence of different vitamin E isomers in the feed, alpha-tocopherol was mostly the only isomer detected in horse tissues.

Conclusion and Recommendations

• The optimal daily intake of vitamin E (in the form of DL alpha-tocopheryl acetate) for adults Standardbred horses feeding on a diet low in vitamin E was found to be between 600 and 1800 mg.
• This recommended dietary intake corresponds to between 1.5 to 4.4 mg of vitamin E per kilogram of a horse’s body weight.
• This research therefore provides valuable insights for horse nutritionists, veterinarians and horse owners in terms of horse diet management, particularly as it pertains to vitamin E intake.