Question: I've moved my horse, a 5-year-old warmblood gelding, to a new barn. Recently, I found out that the amount of hay they feed is very small. In the morning, they get one flake, in the evening two flakes. They also get grain two times a day. During the day, the horses are out in a pasture with no grass for about seven hours. A horse that has just arrived had colic last night, and I believe it's because of an empty stomach. How much hay does a warmblood need who is worked every day moderately for about an hour?
Answer: A 5-year-old warmblood, who is worked moderately for an hour a day, needs more than three flakes of hay per day. A general rule is that a horse needs half a bale of hay per day to satisfy baseline dietary requirements. But depending on the horse and the hay, the amount may vary.
The type of hay greatly determines the amount you should feed the horse. Alfalfa hay, a legume, is rich in nutrients and must be fed sparingly. Timothy hay, a grass, is not as rich and can be fed in much larger amounts. Clover and mixed grass hay have moderate nutritional value. The time that they hay is cut is also a factor for its quality. First-cutting hay, in general, has more stems and is not quite as easy to chew and digest as second cutting.
The scientific way to determine the correct amount of hay for a particular horse is to have the hay analyzed at a lab such as Holmes Laboratory for protein, digestible nutrients and other feed components. Then, you can accurately calculate how many pounds of hay your horse should receive.
Mature horses require 10 to 12 percent crude protein in their diets. Many native or prairie grass hays contain just 6 to 8 percent. A fortified grain concentrate can be used to supplement the ration, increasing its energy, protein, vitamin and mineral content.
If testing the hay is not an option or if the hay varies from week to week, you need to estimate the nutritional quality of the hay and weigh a sample of it. The starting point for a 1,000-pound horse is at least 10 pounds of hay per day. Textbooks, such as Equine Nutrition and Feeding by David Frape (available from Blackwell Publishing, 1-800-862-6657) can give you approximations of nutritional contents of various types of hay.
Mature horses at turnout or in very light work will maintain weight and health on good quality hay. It is important to increase or decrease intake to maintain your horse's weight. Measuring your horse with a weight tape and recording the result on a regular basis will help you to notice any changes. Horses at different ages and stages of growth, development and activity have different dietary requirements.
Hay is not only a dietary necessity, it is a physiological one, too. As you have noticed, horses are at increased risk of colic without the chewing time and gut fill provided with a mostly hay diet. Horses have evolved to eat constantly; therefore, they produce stomach acid constantly. Hay and saliva are alkaline and will act to buffer the stomach acid. Horses are most content when they can nibble almost all the time.
My recommendation is to feed your horse as much good quality hay as he will clean up and add grain only as necessary to keep him at the ideal weight.
Carolyn R. Simmelink, DVM, has been in private equine practice based in Redding, Conn., since 1981. Her specialty is educating new owners eager to provide their horses with the best of care. She has competed in horse trials at Training Level and in dressage shows at Second Level. Both of her daughters are involved in Pony Club.