Biotin (vitamin H)
What it does
Biotin is part of the B group and is needed when keratin is formed — the structural protein that hoof horn, skin and coat are made of. Part of the supply comes from production in the gut.
Why it matters
It is the item horse owners most likely know from the label. Important to note: horn grows slowly, so a good supply pays off over months, not weeks.
When it becomes critical
If the gut flora is disturbed, the self-produced share falls. With poor, brittle hoof horn, biotin is therefore supplemented deliberately — visible change takes months, though, because only newly growing horn benefits.
How much a horse needs
Maintenance: about 3 mg a day for a 500 kg horse. To support hoof horn specifically, higher amounts are often used in practice.
A water-soluble B vitamin needed for building hoof horn and coat. A healthy horse produces most of it itself — the microbes in the large intestine make it, which is why a true deficiency is considered rare under normal conditions. A deficiency shows in the hair before it becomes noticeable in the hoof. ⚠️ Hoof grows slowly: you have to expect at least six to nine months before a supplement can show any effect at all — not weeks.
Cited values
| Type | Value | Unit / context |
|---|---|---|
| Requirement | 0.05 | mg/kg feed dry matter (ration requirement, lower end) |
| Requirement | 0.2 | mg/kg feed dry matter (ration requirement, upper end) |
| Maximum per meal | 3 | mg per 100 kg body mass per day (supplement for hoof horn quality, lower end)Applies only where the hoof horn is already noticeably brittle and there is a corresponding predisposition — not as a general recommendation. |
| Maximum per meal | 4 | mg per 100 kg body mass per day (supplement for hoof horn quality, upper end)Applies only where the hoof horn is already noticeably brittle and there is a corresponding predisposition — not as a general recommendation. |
| Maximum per meal | 12 | mg per 100 kg body mass per day (indicative maximum amount) |
A maximum per meal applies per meal and per kilo of horse — not per kilo of feed. Two small meals can add up to more while each stays below the limit.
The figure marked “applies only …” is a dietary value for horses with a specific pre-existing condition — not for all horses, and not a value to set on your own. Whether and at what level it applies to your horse is something we work out in your analysis; that is why the questionnaire asks about pre-existing conditions.
Possible deficiency signs
- Brittle, dry, dull hair — the coat shows it earlier than the hoof.
- Brittle hoof horn is associated with biotin; whether biotin is really lacking in an individual case cannot be told from the animal alone.
Interactions
- The horse produces biotin itself in the large intestine. With rations very low in structure the gut bacteria work less well — latent deficiencies of water-soluble vitamins are then described.
- Several products side by side — mineral feed, supplementary feed, hoof supplement — add up. More than the body can incorporate brings no additional benefit.