Pete,

Yes,

A horse should eat 1-2% of their body weight a day in roughage (hay) for maintence. So if you have a 1000lb horse (at 1% a day) then it should eat 10lbs of roughage a day broke into at least 2 feedings. So 5 lbs in the morning and 5 lbs in the evening. This is just a base line to start (typically those easy keepers), and I would go more with 1.5-2% so somewhere between 15-20 lbs of hay a day for most horses. You should really weigh all your horses feed, not just go by a flake. The easiest way to weigh hay is get yourself a hand held fist scale (about $5 at the store) and a hay net. Since the net weighs hardly anything, put 1-2 flakes of hay in the net and hook it to the fish scale and hold it up by the handle and see how much it weighs. Once you get a general feel you don't have to weigh it every time. Now this is for horses on little to no exercise. Breeding animals, youngsters and performance horses this will vary depending if you are feeding a grain supplement. Hope this helps.

I was just getting ready to come here and ask that question. Thanks a bunch for your explanation!

Not a problem, if you have any further questions on nutrition let me know. I would be glad to help.

Just a note, hay quality plays a role. There are nutritional differences between different types of hay[grass,timothy,alfalfa...] when it was cut/baled[spring,summer,fall also know as 1st,2nd,3rd cut] At its growth stage[right before/at maturity very nutritional,already bloomed not as rich] and storage age, if its been sitting in a barn for 6mnths to a year it has lost some nutritional value. Color isn't always a factor alfalfa turns very yellow on the outside but can still be very high in nutr. Very green grass hay is not as nutr. packed as your legumes. Look for nice color good leafy consistancey, stem should not be to thick, no foreign matter[sticks,leaves,dirt] and it should have a good smell.

Horse feeders are always concerned about the amount and kind of feed to give their horses. Many variables can affect a horse's nutritional needs: A) temperament and disposition, B) present condition, C) age, D) body type and weight, E) production stage (how many hours a day the horse is ridden, pregnancy, lactation), and F) climatic conditions.

Knowledge about the nutritional requirements of horses is not as comprehensive as for cattle or swine. The nutritional requirements of a light horse may differ from those of a draft horse due to differences in disposition and temperament and particularly the peak energy demands of a horse ridden at fast gaits.

For more information, check it here----------Horse Feeding