Horses are more likely to need vitamin and mineral supplementation if fed one of the following diets:
A forage-only diet (either only hay or grass)
Forage together with unfortified grains (for example, oats)
Forage plus hard feed that is fed at a lower quantity than the manufacturers stated guidelines
As well as diet, a horse’s vitamin and mineral requirement alters throughout his lifetime. Supplementation is particularly beneficial for breeding mares, youngstock, veterans, laminitics and competition horses.
Choosing the right supplement
It is more effective to select a “complete” or multi-vitamin and mineral supplement, rather than targeting a single vitamin or mineral, that may be deficient.
At a minimum you should choose a product containing calcium, phosphorus, trace minerals (including copper, zinc and selenium) and vitamins A, D and E. Although present in pasture, hay and unfortified grains, the concentration of these vitamins and minerals often fall below horse’s required levels.
Complete vitamin-mineral supplements are available in three forms:
Blocks / Bricks
Most blocks provide salt with a very small amount of trace minerals. Whilst offering a relatively low cost option, you can never be certain how much your horse has actually consumed each day!
Granules or Powder
Loose vitamin-mineral supplements give you much better control of the level of intake.
Most high quality supplements in loose form contain very concentrated levels of vitamins and minerals.
For the average weight horse (500kg), typical feeding recommendations are in the range of 30-60g per day.
To be effective at this rate, select a supplement that contains at least 12% calcium, 12% phosphorus, 4,000ppm (parts per million) zinc and 750ppm copper. If the supplement contains lower mineral concentrations, the feeding rate will need to be higher.
Although not as concentrated as a powdered supplement, balancers are still much more concentrated than a fortified feed.
They contain additional protein, which is beneficial for performance horses.
Feeding rates are usually in the range of 450-900g per day.
To be effective at this rate, select a balancer that contains at least 2% calcium, 1-2% phosphorus, 400ppm zinc and 75ppm copper. If the balancer has lower mineral concentrations, the feeding rate will need to be higher.
The choice of supplements is vast, so there will be one that suits the needs of your horse. Remember to choose carefully and follow the manufacturer’s feeding guidelines.
Fiona Watkins, BSc, Pro Dip
The Horse Nutritionist, Independent Equine Nutritionist
If you're not sure which supplement to choose for your horse, Fiona Watkins' brief guide to the role and importance of some of the vitamins and minerals in equine health could help.