What Does It Do?
B12 is vital for enzyme function and for fat, protein and carbohydrate metabolism. B12 is also required for the formation of blood cells and amino acids.
Since it is extremely difficult to assess the true vitamin B12 status of animals the accuracy of any measurement of requirement is doubtful. Most research on the vitamin B12 requirement arrive at a value of 10 mg/kg feed dry matter for maintenance.
This should be regarded as the requirement for average horses and, as with other B vitamins, should be increased for hyperactive and performance horses.
Where Does My Horse Get B12?
It is synthesized by micro-organisms in the horse’s hindgut but additional B12 is obtained through consumption of feedstuffs, especially good quality forage. As with other B-vitamins, B12 may not be absorbed efficiently by the hind gut so horses are dependent on a regular dietary supply.
What About B12Toxicity?
With water-soluble vitamins such as the B vitamins, there are no body stores and any excess vitamin B12 is excreted within 48 hours of intake. As far as I could determine, there has not been any reports of toxicity in horses.
What About B12 Deficiency?
Deficiencies with B12 are more likely than toxicity because it is not a fat-soluble vitamin and daily intakes are required. However, most horses get an adequate amount in their diets as long as high quality forage is a good part of it. If the horse’s diet is dependent on grain or commercial feed concentrates additional B12 might need to be supplemented. It also should be noted that during normal feed mixing there can be about a 10% loss of B12 and if the feed process includes extruding, the loss of B12 may be as much as 30%.
~Peace and Good Feed,