Biotin, also known as vitamin B7, is required in the horse’s diet for the production of keratin – the main protein that forms a strong, durable hoof structure.
Biotin is most commonly known for supporting hoof growth and quality. It also supports many other elements of the horse’s physiology, including fat and sugar metabolism, hair and coat quality and healthy skin.
Although fresh forages and grains naturally contain this vitamin, the amount supplied in your horse’s diet may not be enough to reap the full beneficial effects of biotin for horses.
Severe biotin deficiency is unlikely to occur in horses, but suboptimal intake can contribute to poor hoof and coat quality. Horses with brittle, cracking hooves that struggle to hold shoes properly might benefit from supplemental biotin.
It is recommended that horses consume a minimum of 20 mg of biotin per 500 kg bodyweight to promote optimal hoof health. Feeding rates up to 30 mg per day might be necessary for heavy horses. 
Biotin supplementation is very safe for horses, with no reported cases of toxicity. Like other water-soluble B-vitamins, excess biotin that is not used by the body will be excreted in the urine.
If you are looking to add supplemental biotin to your horse’s diet on its own, Mad Barn’s bulk Biotin powder provides 20 mg of this vitamin in a 4 gram serving size.
Why Horses Need Biotin
Biotin, also known as vitamin B7 or Vitamin H, is essential for optimal function of many enzymes in the horse’s body, not just those involved in building strong, healthy hooves.
It is necessary for four biotin-dependent enzymes that are involved in breaking down fat, sugar, and amino acids to generate energy in all cells of the body.
Horses get this vitamin from the diet and from absorbing biotin that is produced by the microbes in their digestive tract. Biotin is highest in fresh forages like alfalfa and good quality pastures. It is also found in grains like barley, oats, and soybean meal.
Microbes in the hindgut produce biotin, some of which can be absorbed into the horse’s body. Horses with hindgut issues like diarrhea, constipation or bloating, or those maintained on high-grain diets might not be producing much of this vitamin in their gut. These horses would likely benefit from supplemental biotin.
Below are the top 7 reasons why horses need adequate biotin in their diet:
- Healthy hooves: The most common reason to add biotin to your equine feeding program is to support healthy hooves. Ensuring your horse is getting 20 mg per day can make significant improvements in hoof horn quality.
Biotin contains sulfur which is needed to produce keratin – the protein that is found throughout the hoof. Sulfur-containing amino acids in the keratin protein provide its rigid structure, making hooves sturdy and hard. Having adequate levels of biotin in the diet will support strong hooves and could help repair brittle, cracking hooves.
In a study, Lipizzaner horses with previously poor hoof structure were given 20 mg biotin per day. They were found to have less sensitive soles and faster growth of the hoof horn . Although not all studies show a faster hoof growth rate, research consistently shows improved hoof quality, with less brittle or chipped hooves.
- Coat quality: Keratin is also an important component of hair and skin. Biotin helps support keratin production in the hair and skin. Horses with hindgut issues that decrease biotin absorption from the hindgut might benefit from supplementation to support a healthy, shiny coat.
Other nutrients like copper, zinc and omega-3 fatty acids are also important to support coat quality in horses. Well-balanced vitamin and mineral premixes should provide copper and zinc in the correct ratio to optimally support coat quality.
- Healthy skin: Biotin is sometimes referred to as vitamin H for haut, the German word for skin. Severe biotin deficiency that can occur in other animals like pigs usually causes skin lesions and dermatitis.
Although deficiency is rare in horses, having optimal levels might support the right balance of fats in skin cells to help them function properly and prevent flaky, dry skin. 
- Fat metabolism: Biotin is a co-factor for enzymes involved in making fat from sugars and in getting energy from fat. This vitamin helps the mitochondria of all cells of the body breakdown fat efficiently to produce energy.
Biotin affects how these enzymes function by influencing how many of these enzymes are produced by the cells and by binding by-products of their reactions. Horses that are heavily exercised might benefit from higher levels of this vitamin to get the most energy out of the nutrients in their body.
- Exercise tolerance: Given biotin’s role in energy metabolism, it is not surprising that it could support greater exercise tolerance in horses. Horses with lower blood biotin levels reached a critical level of lactate in the blood at lower running speeds, suggesting that horses with higher levels of biotin in the blood might be able to sustain faster speeds during exercise. 
- Blood sugar levels: Biotin is an important co-factor for enzymes that produce energy from sugars (glucose) and that store glucose in the body as glycogen so that it can be used during exercise or fasting.
Some reports in other animals suggest biotin supplementation helps lower blood glucose levels after a meal and improves insulin sensitivity.  More studies are needed to know the extent to which this vitamin supports blood sugar levels in horses, particularly those with equine metabolic syndrome or easy keepers.
- Mood and anxiety: Anecdotal reports suggest that B-vitamin supplements have a calming effect on horses and are often used for performance horses during travel and competition.
Specific research in this area has not been performed in horses, but the stress of competition and travel can lead to hindgut issues in some horses which might limit B-vitamin production by the gut.
In humans, B-vitamin supplements have been shown to improve stress levels, but more research is needed to know the specific role of biotin and whether biotin alone improves mood in horses.   
Reasons to Consider Biotin Supplements
There can be several reasons why your horse might not be getting enough biotin from their feed to support healthy hooves, good coat quality and optimal energy metabolism.
The hindgut microbes produce biotin and other B vitamins as a by-product of fibre fermentation. Therefore, anything that impairs hindgut health might lead to low B vitamin availability for the horse.
Horses on broad spectrum antibiotics could benefit from supplemental B-vitamins including extra biotin to make up for the fact that some gut microbes will be killed off and therefore less of these vitamins will be produced by the gut.
Horses on high-grain, low-fibre diets will have less fibre fermentation occurring in the hindgut and may have lower biotin production by their gut microbes. They are also at higher risk for hindgut disturbances like diarrhea and hypermotility which could decrease biotin production and absorption.
High-grain diets have also been linked to behavioral changes in horses due to shifts in the gut microbiome. B-vitamins are thought to have a calming effect on the nervous system. These changes in mood could be a sign of lower B-vitamin production and absorption.
Older horses tend to have smaller microbial populations in their hindgut and might benefit from B-vitamin supplementation to make up for lower synthesis and absorption from the hindgut. 
For horses that require additional B vitamin supplementation, Mad Barn offers a B-Vitamin Pak that provides a complex of B-vitamins made up of thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folic acid (B9), and cobalamin (B12). Each serving provides 20 mg of biotin.
How to Feed Biotin
Before adding minerals or vitamins on a one-off basis, we recommend a complete diet analysis to understand your horse’s nutritional needs. You can submit your horse’s diet for analysis online and one of our nutritionists will provide a complementary assessment.
Depending on your horse’s individual needs, exercise level and health status, you may be advised to feed biotin at the typically recommended dose of 20 mg per day for a 500 kg horse. Heavier horses may require up to 30 mg a day whereas 5 – 10 mg should be sufficient for most ponies and donkeys.
Mad Barn’s bulk biotin powder can easily be top-dressed with a single 4-gram scoop providing 20 mg of biotin. This product is highly palatable and will likely be well-tolerated as a top dressing.
It may take several months to notice changes in hoof health when feeding supplemental biotin. This vitamin supports formation of new keratin proteins rather than improving the existing hoof structure.
It takes approximately 8 months for new hoof horn to grow out from the coronary band to the level of the sole. However, changes to horn growth may be visible earlier.
In one study, smoother coronary borders were noticed after 7 weeks of 20 mg per day of biotin. Improved hardness and lower sensitivity in the soles were observed after 4 months of supplementation. 
If you notice improvements after several months, you will need to continue supplementing biotin to have persistent benefits to hoof health. Removing biotin from the diet in horses that have shown improvements will likely cause hoof condition to deteriorate again. 
If your horse does not respond to biotin alone, it could be that other nutritional factors in the diet need to be balanced in order to support hoof health.
Most notably, the minerals zinc and copper should be in proper balance to promote keratin synthesis. This is another reason to consider a complete diet evaluation prior to beginning biotin alone and waiting months before you may see noticeable changes.
Keratin, like all proteins, is made up of amino acids. A well-balanced diet with proper levels of key amino acids will also be beneficial to support healthy hooves. Lysine, methionine, and threonine are the amino acids that are most commonly low in equine diets. Bringing these to optimal levels can support overall health and healthy hooves.
In addition to the diet, other factors like insulin resistance, recurrent laminitis and seasonal changes might be affecting your horse’s hoof quality. A balanced approach with regular, high quality hoof care and a well-formulated diet is likely to be most beneficial for hoof health.
Biotin Research in Horses
The majority of biotin research in horses focusses on hoof health, quality and growth. Many studies have shown that adding this vitamin improves hoof structure after several months of supplementation when given at a dose of 15-30 mg per day.
The most comprehensive study on biotin benefits for hoof health was conducted with 42 Austrian Lipizzaner stallions. Twenty-six horses received 20 mg of biotin per day and 16 horses received a placebo – a daily tablet with no biotin.
The majority of these horses had soft white lines and crumbling, fissured hooves before starting the trial. After 7 weeks, almost half the horses given biotin had smoother coronary borders.
By 4 months they had harder hooves and less sensitivity in the soles. At 9 months of supplementation, there were definite improvements in white line quality and in overall scores of hoof quality. 
A similar study was performed with eight ponies, in which four ponies were given 20 – 30 mg biotin per day (based on body weight) and the other four were not supplemented. After 5 months, the group given biotin had a 15% faster growth rate of the hoof horn and 5 mm more growth of the hoof capsule. 
Research shows that it can take many months to notice significant changes in hoof health and structure when feeding biotin. It takes several months for new hoof tissue to completely replace the hoof horn from the coronary band to the sole.
For ongoing results, this vitamin needs to be fed on a continuous basis to maintain keratin production and hoof integrity.
How Much Biotin Do Horses Need?
The NRC’s Nutrient Requirements for Horses does not establish a strict dietary requirement for biotin levels in the equine diet. However, some sources recommend feeding at a rate of 3 mg/kg of dry matter intake.
For optimal health and well-being, biotin is often recommended in a dosage range of 15 – 30 mg per day. This vitamin is expensive to feed in comparison to other nutrients and might have a shorter shelf life depending on how it is stored and what form it is supplied in.
Feeding less than 15 grams per day is not recommended for a 500 kg horse. One study showed that horses given 15 mg per day had greater growth rates and hardness after 10 months compared to horses given only 7.5 mg per day. 
Horses that have a heavier burden on their hooves through high levels of exercise might benefit from up to 30 mg per day while smaller animals like ponies and donkeys might see benefits from 5 – 10 mg per day. 
Feeding higher amounts is unlikely to have an additive benefit for hoof health. The best way to support your horse’s hoof growth is by ensuring their diet is balanced and provides adequate amounts of a complete array of vitamins and minerals.
Submit your horse’s diet for evaluation and one of our nutritionists can tell you whether it provides sufficient amounts of the vitamins and minerals that are most important for hoof growth.
For a fully balanced vitamin and mineral supplement, our Omneity premix provides 20 mg of biotin in each serving and is formulated to meet the core nutritional needs of most horses.
Mad Barn’s AminoTrace+ mineral and vitamin supplement also providing 20 mg of biotin per serving. This product is designed to support horses with metabolic issues like equine metabolic syndrome or high iron intake.
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- Comben, N. et al. Clinical observations on the response of equine hoof defects to dietary supplementation with biotin. Vet Rec. 1984.
- Josseck, H. et al. Hoof horn abnormalities in Lipizzaner horses and the effect of dietary on macroscopic aspects of hoof horn quality. Equine Vet J. 1995.
- Proud, V.K. et al. Fatty acid alterations and carboxylase deficiencies in the skin of biotin-deficient rats. Am J Clin Nutr. 1990.
- Lindner, A. et al. Effect of biotin supplementation on the vLa4 of thoroughbred horses. J Equine Vet Sci. 1992.
- Xiang, X. et al. Effects of biotin on blood glucose regulation in type 2 diabetes rat model. J Hygiene Res. 2015.
- Young, L.M. et al. A Systematic Review and Meta-Analysis of B Vitamin Supplementation on Depressive Symptoms, Anxiety, and Stress: Effects on Healthy and ‘At-Risk’ Individuals. Nutrients. 2019.
- Destrez, A. et al. Dietary-induced modulation of the hindgut microbiota is related to behavioral responses during stressful events in horses. Physiol Behav. 2019.
- Destrez, A. et al. Changes of the hindgut microbiota due to high-starch diet can be associated with behavioral stress response in horses. Physiol Behav. 2015.
- Mshelia, E.S. et al. The association between gut microbiome, sex, age and body condition scores of horses in Maiduguri and its environs. Microbial Pathogenesis. 2018.
- Geyer, H. and Schulze, J. The long-term influence of biotin supplementation on hoof horn quality in horses. Schweizer Archiv fur Tierheilkunde. 1993.
- Reilly, J.D., et al. Effect of supplementary dietary biotin on hoof growth and hoof growth rate in ponies: a controlled trial. Equine Vet J. 2010.
- Buffa, Eugene et al. Effect of dietary biotin supplement on equine hoof horn growth rate and hardness. Equine Vet J. 1992.