Horse Power for Natural Farms:
Feed and Water Requirements

Pasture is a great source of forage because the horses harvest it themselves and get important exercise in the process. The pasture also gets fertilized by the wandering horses. We have found that fields in pasture have made the most dramatic increases in organic matter on our farm. The fine root systems of the grasses are good at building soil structure and organic matter. Horses need 1 to 2 acres of pasture per horse, depending on pasture productivity. Hay for horses must be free of dust and molds, otherwise it may cause respiratory problems. My general rule of thumb is a bale of hay per horse per day, but that can be reduced if your horses are small or hay is expensive. As a general rule you will need about 250 bales of hay per horse for winter feed. You may need more if you have to supplement an unproductive or dry pasture.
It is difficult to estimate the amount of oats you will need annually, which depends on the frequency and nature of the work the horses are doing and whether or not you are working pregnant or lactating mares. A starting point would be allow one metric ton (2,200 pounds) per horse per year for a horse worked frequently. If you are working lactating mares, feed them vegetable oil in order to get enough calories into your mares.
Forages and grains grown in an area that is low in selenium will be low in selenium, one of the most important trace minerals required by horses. If you are depending on locally grown feeds that have not been fortified with additional selenium, you may want to supplement your horses' diet. Feed dealers can get block or loose trace mineral salt with elevated levels of selenium. The requirement for horses is 1 to 2 mg. of selenium per 1,000 pounds of horse per day.
For hard working horses loose salt added to the grain ration is better than a salt block, because horses cannot get enough salt by licking from a block. T-M-SE Trace Mineralized salt with Selenium from the Canadian Salt Company has 25 mg. selenium per kilogram. Feed 80 to 160 gram per horse per day.