When To Supplement Vitamin E?

The availability and necessity of vitamin E in equine diets is well established. Vitamin E is a fat-soluble vitamin, with an important role as an antioxidant, to protect body tissues, enzymes, and other intracellular substances from damage due to oxidative stress. It is also essential to immune, cardiovascular, circulatory, neuromuscular, and reproductive functions.

When healthy horses are given frequent access to fresh good quality pasture, vitamin E requirements are likely to be met. However, as we transition into Autumn, pasture access is often limited, with conserved forages such as hay and haylage making up a greater portion of the daily forage intake. Immediately after forage is cut for conservation, vitamin E levels start to decline, resulting in levels 20-80% less than fresh grass. Grass quality also declines over winter months, meaning even those with constant access to pasture are unlikely to receive sufficient levels of vitamin E.

Due to this, it is important for all horse’s to be managed on the recommended rate of a fully fortified feed or ration balancer, to ensure nutrient requirements are met. For most horses, the antioxidants they get in their grass and hard feed is enough to stop free radical damage, but for some horses feeding additional anti-oxidants in the ration is required to further support muscle function. Horses that would benefit from vitamin E supplementation include, those with restricted pasture access, performance horses undergoing intense exercise, breeding stock, horses with neurological or neuromuscular problems, following stressful events such as weaning or travel, or following injury or illness to enhance recovery.

For performance horses in a moderate to high workload, vitamin E’s role as an antioxidant is increasingly important in protecting tissues and cells from free radical degradation. These products of oxidation can cause irreparable damage to cell membranes throughout the horse’s body, often leading to muscle stiffness and soreness in horses without sufficient vitamin E stores. It is the job of antioxidants to 'mop up' free radicals to stop this damage from occurring.

Vitamin E also has the potential to positively influence fertility in broodmares, and improve the passive transfer of antibodies through colostrum. Supplementing mares with additional vitamin E at a rate of 2500iu per day during the last four weeks of pregnancy has been shown to increase IgG and IgM of the mare’s milk in the first three days after birth, as well as increasing her serum levels of alpha-tocopherol (vitamin E). The same effect was seen in the foals, having elevated serum alpha-tocopherol and IgM levels.

When supplementing vitamin E, natural sources are far more potent than synthetic forms. Natural vitamin E is recognized as “d-alpha-tocopherol,” and is made up of a single isomer. Synthetic vitamin E, termed “dl-alpha tocopherol,” contains a mixture of eight different isomers, four tocopherols and four tocotrienols. Of these eight, only one is molecularly equivalent to natural vitamin E.

Controlled studies and Kentucky Equine Research indicate that the natural vitamin E supplement, Nano-E is superior to synthetic and other natural vitamin E sources. The vitamin E in Nano-E is encapsulated in nanoparticles and surrounded by a hydrophilic (water-loving) outer layer, allowing it to be rapidly and evenly released in water-based environments, such as the gastrointestinal tract. This unique delivery system increases the bioavailability of vitamin E, optimising the amount that is absorbed into the bloodstream. 4 to 8ml Nano-E should be provided per day as maintenance for stabled horses or those on poor pasture, supplying 1000iu to 2000 iu vitamin E. This can be increased to 12ml (3000 iu) for horses in training, lactating mares, stallions and newborn foals, and up to a maximum of 20ml (5000iu) to preload prior to competition or racing. Click here to read more about Nano-E.