Vitamins are the topic for discussion in this issue. Horses like us need vitamins for normal bodily functions. These needs will vary according to the age and stage of each horse and their living situations. For example stabled horses have different requirements than paddock horses. Horses on well-managed improved pasture are likely to require little or no vitamin supplement.
Vitamins fall into two broad groups; these are “fat soluble “ and “water soluble“ vitamins.
Horse owners need to be cautious not to assume vitamin needs for horses are the same as other domestic animals. This is evident from research done with horses in strenuous work when needs for vitamin B is increased.
FAT SOLUBLE VITAMINS.
VITAMIN A. Important for vision and normally found in fresh green forage but is also present in yellow corn. Vitamin A is destroyed over time by heat and light. Horses deficient in Vitamin A have an increased susceptibility to respiratory infections, infertility and lameness problems.
VITAMIN D. Involved in the metabolism of calcium and phosphorus. Deficiencies reduce bone calcification, result in stiffness and abnormal gait, back pain and swollen joints. Adequate Vitamin D is normally obtained from sun cured hays or from exposure to light.
VITAMIN E. This is necessary for normal cell structure and deficiency is responsible for problems such as white muscle disease and anaemia. Selenium and Vitamin E work together in the prevention of white muscle disease. Vitamin E is often linked to fertility and the endurance capacity of horses in heavy work. Prime lucerne is an excellent source of Vitamin E.
VITAMIN K. While the exact requirements have not been determined Vitamin K is essential for blood clotting. There is some storage of Vitamin K in natural feeds. Leafy grasses and legumes are good sources and therefore no supplementary source is normally necessary.
WATER SOLUBLE VITAMINS.
B COMLEX VITAMINS. Adequate amounts are usually found in good quality hay and pasture. Hardworking horses may require greater amounts.
THIAMIN B1. This is more likely to be the B complex vitamin lacking if feed is of poor quality. Deficiency causes amongst other things loss of appetite and weight and muscle coordination. ( brewers yeast is an excellent source of thiamine ). Horses eating bracken fern can suffer from Thiamine deficiency.
RIBOFLAVIN B2. Involved with energy metabolism B2 is usually found in much higher levels than estimated from good quality hay or pasture.
VITAMIN B12. This is not produced by plants, contains Cobalt and is required for normal production of red blood cells. Deficiencies can cause anaemia, weight loss, reduced performance and poor hair coat. These can be found in the high performance horse.
FOLIC ACID. Also involved in the formation of red blood cells and again deficiency causes anaemia. Exact requirements are unknown and although levels are lowered through sweat, horses grazing good pasture have an excellent source of folic acid.
BIOTIN. Biotin found in wheat, barley, sorghum, oats and in rice bran is almost completely unavailable for utilisation. That found in maize, yeast, and soyabean is accessible. Biotin is used for improving strength and conformity of the hoof.
ASCORBIC ACID, VITAMIN C. Horses are able to synthesise Vitamin C from glucose. The many claims in support of the benefits of Vitamin C supplementation are yet to be proven beyond doubt by scientific study.
While much of the proceeding work has been of a more technical nature the important point to remember is that supplementation should not be added without reason. As per our advice with minerals either use a pre mixed feed or when using a supplement stick strictly to the guidelines set out by the manufactures.
The level of Mineral and Vitamin Premix added by Mi-Feed to our eleven horse feeds varies according to the recommended use of the particular feed being used. Providing good quality hay and well managed pasture is available, under normal circumstances additional mineral and vitamin additives should not be necessary. If problems with horse health occur owners should consult with the equine specialist.