The Story of B Vitamins in Horse NutritionBy Kentucky Equine Research Staff · June 5, 2012
The B vitamins are a group of water-soluble vitamins, each with its own distinct use and chemical properties. Being water soluble means that they are not stored in the body, and so are rapidly excreted in the urine should there be an excess supply. Horses can to some extent rely on their own “home-made” B vitamins to meet their full requirements. While the horse manufactures his own niacin (formerly B3), the remaining B vitamins are produced as part of the mutual working contract between the horse and his microflora by the bacteria of the hind gut. Any shortfalls in B vitamin production are supplemented through the diet by way of pasture and hay, provided there is ample supply. Vitamin B12 is the only B vitamin not produced in plants, and therefore the horse must rely on the supply from the hindgut bacteria.
Why feed it?
Little research is available on the subject of vitamin B requirements in horses and what proportion of these are met by the horse’s naturally manufactured supply. While a horse will rarely show signs of deficiency, there may be times when a supplemental source of B vitamins can be the difference between meeting minimal requirements for health and optimal requirements for top performance. There are certain times when a B complex vitamin supplement may be beneficial due to a diminished supply from both internal and external sources. These include:
- Horses on high grain, low forage diets, or those on very poor quality forage.
- Horses in high stress situations or during extreme exertion (endurance, traveling, racing)
- Horses with reduced appetite and general ill thrift due to illness or stress.
- Horses on broad spectrum antibiotics where hindgut bacteria will be compromised.
- Horses that have poor digestive health such as diarrhea or extreme parasite burden.
- Very young horses with incomplete gut microflora populations.
- Very old horses with diminished digestive efficacy.
B complex vitamin supplements have shown good results in the field for the performance horse and as an aid to the stress of travel and competition. Seeming to give the horse a natural lift, these supplements, though unproven by science, have a great following among experienced horse people. Some B vitamins have been studied more than others, and beneficial effects of feeding supplemental sources of these vitamins have been reported both in the academic press and in the field.
Some research has found that thiamine (B1), while being made in good amounts in the hindgut, is still required in the diet, but luckily thiamine is well supplied in green forage and other sources such as brewer’s yeast. Severe thiamine deficiency can occur when horses eat bracken ferns, but clinical deficiency is otherwise rare. Feeding higher levels of thiamine has historically been a remedy for calming the nervous horse. Though it won’t work for all horses, there is some evidence to suggest a calming influence in individuals that display undesirable behavior due to thiamine deficiency or increased requirement.
Cobalamine (B12) is made in plentiful supply by microorganisms as long as there is sufficient dietary cobalt. It is not available from plants, but is available in brewer’s yeast and milk powder. It is widely used to improve appetite, avoid anemia, and enhance performance, though deficiency has not been documented in horses. Anecdotal evidence suggests that horses do respond favorably to supplementation. Horses can store some B12, unlike any other B vitamin.
How do you feed it?
Most B vitamins are found in good quality fresh forage, which should always be the basis for a balanced diet. For horses doing light to moderate work, this is likely all that they will ever need. Supplying large quantities of B vitamins will not make a horse run faster and jump higher, but sometimes a supplemental source can help to supply optimal rather than minimal levels, and can allow the horse to perform to his full potential.
As mentioned above, brewers yeast can be an excellent source of B vitamins, but commercial supplements are also available with a consistent level of each of the vitamins. B vitamin supplements can be damaged by heat, light, and humidity. Furthermore, some B vitamins are incompatible with one another. Thiamine (B1) is incompatible with riboflavin (B2) and both are incompatible with cobalamin (B12) so in order for them to be fed together in a form that will work, some of these vitamins need to be coated for protection and to preserve activity and efficacy. In commercial supplements, the B vitamins are often coated with waxes, sugars, or gums to increase their stability and ensure consistent quality in each scoop given to the horse. If you are unsure whether your supplement contains coated vitamins, contact the manufacturer for further information. Many premixed feeds also contain coated B vitamins in their premixes, and if these feeds are used, further supplementation is rarely necessary if the feeds are fed at recommended rates.
Where do you get it?
If you feel your horse could benefit from B vitamin supplementation you can ask at your produce store for B vitamin supplements including brewer’s yeast. If you feed a premixed feed or all-around supplement, study the label for B vitamin content and make sure you are feeding the right amount.
For more information about commercial vitamin B supplements and how to use them for optimal performance efforts, contact an equine nutritionist.