Cobalt
What it does
Cobalt does not act directly but as a component of vitamin B12. The microbes in the gut build this vitamin from the cobalt in the feed, and it is needed for blood formation and nerve function.
Why it matters
In practice this item takes care of itself as long as the gut flora is working and the ration is normally composed. It appears in the calculation so that it can be ticked off.
When it becomes critical
With usual feeding, cobalt is covered; genuine undersupply is not described in horses. It can at most get tight on very poor sandy and weathered soils.
How much a horse needs
There is no figure for a daily amount of cobalt. Orientation comes from the feed itself: roughly 0.1 mg in each kilogram of dry matter is regarded as safe.
A component of vitamin B12; the horse's gut flora makes what it needs from it.
Cited values
| Type | Value | Unit / context |
|---|---|---|
| Requirement | 0.05 | mg/kg feed dry matter (maintenance) |
| Requirement | 0.1 | mg/kg feed dry matter (pregnant) |
| Requirement | 0.07 | mg/kg feed dry matter (lactating) |
| Requirement | 0.13 | mg/kg feed dry matter (growth) |
| Requirement | 0.07 | mg/kg feed dry matter (work) |
| Tolerance limit | 25 | mg/kg feed DM |
Careful when comparing: the requirement is given **per day**, the upper limit **per kilogram of feed dry matter**. These are different reference bases and cannot be compared directly. The upper limit is also not a target — it is the amount at which harm begins.