A friend recently asked me what was the correct feeding order, hay first or grain? This is a great question, and despite the controversy, I cannot find any hard data that suggests feeding hay first will have an effect on the horse’s health, unless over 50% of the diet is concentrate per feeding.
First, you need to look at the big picture. Horses by nature are grazing animals, not meal eaters. A horse should be provided with 1.5 to 2% of his total body weight per day in forage, i.e. a 1000 pound horse would receive 15-20 pounds of hay per day, depending on caloric needs and type of forage. To minimize waste I like to see the forage placed in a slow feed net, this also helps to replicate grazing.
The dietary needs are then balanced with a concentrate that may vary in weight from 1 pound to no more than 5 pounds per feeding. This where you really need to pay close attention to the feed rate and directions on the product you select. Due to the small size of the horse’s stomach, it is never recommended to feed more than 5 pounds of concentrate at any one feeding.
Horses are continuous grazers, and will graze 18 hours in a 24 hour day. To maintain normal gut function, saliva is produced up to 30 gallons in a 24 hour day, during this gazing period. This helps the horse maintain normal gut function, stabilizing the intestinal pH and keeping ulcers in check. Not to mention the periodontal impact.
Having forage first can be a benefit for those horses that tend to bolt their feed or concentrate. Again we need to look at the big picture and time between feedings. I also realize that for large farms and commercial operations it may be more labor intensive to make the feeding process a two-step program. If you board your horse a great treat is providing a serving of an additional forage source, such as a hay extender.
So hay or grain first is really not the issue, rather a balanced feeding program and feeding schedule is key.