is their an equation to tell you approximately how much hay and grain to feed a horse.?

http://www.equisearch.com/horses_care/feeding/hay/...

Here is a vet link for you....

it really depends on the grain. On the back of the bag, where the nutritional facts are, they usually have instructions for different conditioned horses.

For Senior and pelleted feeds you usually feed .5% (1/2%) of a horses body weight in that particular feed.

Usually when they reference it on the back, they intent it to be a primary feed. So you can cut it in half and ration it to your horses condition exercise plan etc.

Be careful not to condition your horse to the point of peak, and then let them have a few days break. the horse is used to a moderately heavy work and then with the off days, the horse still has to process the same feed as when they were in heavy work. If this happens your horse will "tie" up. Also known as Monday Morning Sickness.

a horse should be fed one and one half pounds of hay per hundred pounds of horse. or about 15 lbs of hay per 1000 lb. horse. They should be fed at least 3 times per day. A horse nibbles all day long in the wild and never eats all of its food at one time. No grain should be fed unless the horse is working or a hard keeper. Look up horse nutrition on the internet.

If your horse isn't in a field grazing all day, then they will need more hay.

At my barn, the horses get usually 2 medium-large flakes of alfalfa or grass and the really big 17 hand plus warmbloods get three. The larger ponies get one big or two small alfalfa.

The rule of thumb has always been 20lbs of hay and 5lbs of feed per day. Depending on the horse it can be more or less.

You should always ask your vet for help with feeding amounts because every horse is different.