By: Madeline Boast, MSc. Equine Nutrition
The Role of Biotin in the Body
Biotin is a common name for vitamin B7. It is a water-soluble vitamin that plays a role in a variety of processes in the body. Not only is biotin important for hoof health through the production of keratin, but biotin is also involved in various enzymes that are essential in carbohydrate, fat, and protein metabolism. Therefore, it is essential for the conversion of feed into energy for the horse to use.
Biotin deficiency in horses is uncommon, in fact, even in horses with weak or brittle hooves, their plasma biotin levels are normal. With that being said, the research clearly shows that when biotin is supplemented at a therapeutic level the plasma biotin level increases. Due to biotin being a water-soluble vitamin toxicity is not a major concern as the horse will simply excrete the excess.
Horses have two sources of biotin intake; there is the biotin that is provided in their feed and the biotin produced by the microbes in the hindgut. Fresh forages are rich in biotin as well as grains such as oats. Other common feed ingredients that provide biotin are soybean meal and alfalfa. This is not an extensive list as biotin is provided in many equine feed ingredients. As mentioned above, the microbes in the hindgut also produce biotin as a byproduct of forage fermentation, which is then absorbed by the body. Unfortunately, we have limited knowledge of the hindgut microbial environment so do not know exactly how much biotin is produced or how much the horse is able to absorb.
There is clear research that illustrates positive results from therapeutic doses of biotin. It is recommended that between 15-30 mg/day be supplemented for therapeutic doses depending on the weight of the horse. General guidelines for a 500 kg horse are 20 mg/day.
Most of the research on biotin is not recent, but I have pulled 3 different studies to touch on for this article. This first study was published in 1984 and investigated 40 cases of horses with various hoof health issues. These horses were supplemented with varying amounts of biotin for multiple months. The authors were able to show varying degrees of improvement in the hardness, integrity, and conformation of the hoof horn in all supplemented cases. Based on this study they recommended 10-30 mg of biotin a day depending on the horse’s body weight for 6 to 9 months. It was also noted that supplementation must continue for the benefits to last as the hoof will revert to the original state when supplementation is halted.
This second study used Lipizzaner horses and was published in 1995. The horses were supplemented with 20 mg of biotin for 9 months or supplemented with a placebo for 9 months. It was reported that the treated group showed significantly improved hoof qualities compared to the beginning of the trial and the placebo group.
An extremely important note when discussing biotin supplementation is that this is not going to be effective in producing benefits if your horse is on an unbalanced diet. If you have been reading the monthly Hoof Doctor articles, you will know that there are a variety of nutrients that are crucial to hoof health, therefore, if you are adding biotin to a horse that is deficient in zinc for example, you are not effectively treating the issue. As a nutritionist, I always ensure a diet is balanced prior to opting for adding various supplements. If your horse has poor hoof health, I strongly encourage you to get your hay tested and their nutrition evaluated prior to adding a biotin supplement.
The final study I want to mention is one that looks at a mixed hoof health supplement, this is not simply biotin. This study is more recent as it was published in 2022. The supplement that was investigated included biotin but also contained copper, zinc manganese and omega-3 fatty acids. The horses were supplemented for 32 weeks and showed a greater hoof growth rate, they also had greater plasma biotin concentrations.
So, there is good scientific evidence for the supplementation of biotin, but I caution against adding these supplements in the hope of hoof health improvement when you haven’t had your horse’s diet evaluated by a nutritionist. Additionally, the biotin will only impact new hoof growth, therefore it will take months prior to seeing any noticeable differences. The other consideration when supplementing biotin is that the shelf life is limited. It is estimated to have a 6-month shelf life – therefore, purchasing from a reputable company and using the supplement right away is recommended.
Biotin is an important vitamin for horses, and it is normally abundant in their diet. However, there is good scientific evidence supporting the addition of biotin in the diet to promote hoof health. If you are concerned about your horse’s hooves and nutrition, the first step should be testing your hay and having their diet balanced by a qualified equine nutritionist. Once this has been done, adding biotin to reach the recommended therapeutic dose may improve your horse’s hoof health.
If you are curious to learn more about hoof supplements, next month’s article will dive deeper into this topic. If you have shopped around in a feed store for hoof supplements, I am sure that you realize just how many there are. It can be difficult to know what is best for your horse. Should you add just biotin, or should you add a supplement with minerals too? – it can be tough to know. Stay tuned for next month’s article to continue expanding your knowledge on equine nutrition and how it relates to hoof health.
Written by: Madeline Boast, MSc. Equine Nutrition
About the author: Madeline Boast completed her master’s in Equine Nutrition at the University of Guelph and started an independent nutrition company known as Balanced Bay. She has worked with a variety of equids – from miniature ponies to competing thoroughbreds. Through Balanced Bay she designs customized balanced nutrition plans that prioritize equine well-being. This includes diets for optimal performance as well as solving complex nutritional issues and everything in between. For additional information see www.balancedbay.ca
Comben, N., Clark, R. J., & Sutherland, D. J. (1984). Clinical observations on the response of equine hoof defects to dietary supplementation with biotin. The Veterinary Record, 115(25-26), 642-645.
Josseck, H., Zenker, W., & Geyer, H. (1995). Hoof horn abnormalities in Lipizzaner horses and the effect of dietary biotin on macroscopic aspects of hoof horn quality. Equine Veterinary Journal, 27(3), 175-182.
Reilly, J. D., Cottrell, D. F., Martin, R. J., & Cuddeford, D. J. (1998). Effect of supplementary dietary biotin on hoof growth and hoof growth rate in ponies: a controlled trial. Equine Veterinary Journal, 30(S26), 51-57.
Suagee-Bedore, J. K., Hebrock, S., Sundin, O., Lengi, A. J., Corl, B. A., & Worth, M. (2022). Thirty-Two Weeks of Oral Supplementation with LinPro™ Increases Hoof Growth in Healthy Mares. Journal of Equine Veterinary Science, 117, 104086.