Vitamin supplementation in horses is generally not needed since common feeds normally contain adequate amounts. Vitamin A is found in green leafy plants or yellow grain such as corn, but may be deficient in the winter months when green grass is unavailable and if hay quality is poor. Vitamin D is essential for calcium and phosphorous deposition in bone formation. However, deficiencies rarely occur, since animals exposed to sunlight synthesize sufficient vitamin D to meet their needs. Vitamin E is abundant in most rations and seldom needs supplementation. The B vitamins are synthesized by the horse and supplementation is not normally needed in a healthy, well-fed horse.
The most common sources of vitamins are good quality pastures, hay and grains. Vitamin deficiencies occur primarily when horses are sick or stressed, or if feed is improperly processed and stored over long periods of time. In these cases, vitamin supplementation may be necessary. Most commercially available rations are supplemented with the optimum daily requirement.
Table 1 indicates the normal daily vitamin supplementation utilized by most feed companies in developing their rations. Horsemen who are utilizing whole grain rations such as an oat ration, may want to consider a vitamin supplement of this nature. However, if a ration is balanced for vitamins, the adding of additional supplements is unwise. Many vitamins can be toxic if over-fed, and excess vitamins normally result in the same problems caused by deficiencies of that vitamin. Therefore, it is never wise to feed more than one vitamin supplement and risk overdosing horses with vitamins.
|Table 1. Normal Daily Vitamin Supplementation|
|Vitamin A||20-30,000 I.U.|
|Vitamin D||200 - 300 I.U.|
|Vitamin E||1,000 I.U.|
|Pantothenic Acid||40 mg.|
|Vitamin B12||.03 mg.|
A source of fresh, clean drinking water is essential for horses at all times. Daily consumption may average 10 to 12 gallons, with much higher amounts consumed at hoard work and/or hot weather.
The LSU AgCenter and the LSU College of Agriculture