Feeding Horses During A Hay Shortage

Feeding Horses During A Hay Shortage
Gary Heusner, Ph.D.
Professor, Extension Horse Specialist
During times of droughty conditions we are reminded even more the importance of roughage in a horse's diet. Many areas of the South East have or will have low supplies of hay because of not being able to make hay as well as having to feed hay to many horses that normally would be maintained on pasture. Horses require roughage in the diet to maintain normal digestive function. Horses have a microbial population in the hind gut that is similar in types and numbers per volume of the hind gut as the cow has in the rumen. When the horse does not receive adequate roughage the microbial population is altered and digestive problems may occur. The horse also needs adequate levels of roughage in the diet to maintain normal behavior. It is not known whether inadequate levels of roughage create digestive disturbances that lead to altered behavior or the horse simply needs to chew a minimum number of times per day to accommodate or mimic normal grazing behavior. Horses in a free grazing situation with enough available forage will spend seventy percent or greater of their time grazing. In reality the minimum chew time a horse needs probably fulfills both functions of maintaining normal digestive function and normal behavior.
With the above in mind what is the minimum amount of hay that can be fed to a horse and what roughage sources may be substituted for hay? The minimum level of roughage a horse should receive per day is .75 to 1.0% of the horses's body weight in hay or hay equivalent. This means an 1100 pound horse should consume 8.25 to 11 pounds of hay or hay equivalent per day. Hay equivalent is a key word as complete pelleted feed with a high fiber content is not the same as a feed that has high levels of fiber (ie 18-25% crude fiber) that has not been ground and/or pelleted. Hay chopped, ground, or pelleted does not provide the same hay equivalent as a hay fed from a bale or even chopped to less than one inch in stem length. Another important rule when limiting hay intake is to make sure the hay or hay equivalent roughage source makes up at least 50% of the total feed consumed per day.
Two readily available sources of roughages that can be partially or completely substituted for hay in a horses's diet are beet pulp and cottonseed hulls. Beet pulp can make up to 20-25% of the total diet of a horse. Beet pulp has a crude fiber and energy content similar to alfalfa hay for horses. The 1100 pound horse doing light work can be maintained on 9.5 pounds of Bermudagrass hay and 9.5 pounds of a grain-sweet feed that contains 5-7 % crude fiber. If beet pulp were used at up to 25% of the diet, the horse could be fed as follows:
POUNDS / DAY
Bermudagrass Hay 4.75
Beet Pulp 4.75
Grain-sweet feed 9.50
(10% crude protein, 5-10% crude fiber)
The same 1100 pound horse doing moderate work could be fed as follows:
POUNDS / DAY
Bermudagrass Hay 5.25
Beet Pulp 5.25
Grain-sweet feed 11.00
(10% crude protein, 5-7% crude fiber)
Cottonseed hulls have a much higher fiber content than Bermudagrass hay. Neutral detergent fiber content of cottonseed hulls will be around 80% whereas Bermudagrass hay will range from 65 to 70. Therefore cottonseed hulls will provide more bulk or fiber so that less of it can be fed with more grain. We ( the University of Georgia Horse Center) have successfully fed diets containing 20-30% cottonseed hulls.
Cottonseed hulls can be fed to an 1100 pound horse doing light work as follows:
POUNDS / DAY POUNDS / DAY
Bermudagrass hay 5.0
Cottonseed hulls 2.0 5.5
Grain - sweet feed 10.5 12.5
(12% crude protein, 5-7% crude fiber)
The same horse doing moderate work can be fed as follows:
POUNDS / DAY POUNDS / DAY
Bermudagrass Hay 6.5
Cottonseed hulls 4.0 8.0
Grain-sweet feed 12.00 15.0
(12% crude protein, 5-7% crude fiber)
The cottonseed hulls should be mixed with the grain portion of the diet. It is also important to use a textured feed (not pelleted) when feeding cottonseed hulls and/or beet pulp. Any changes in the horses diet should be made gradually over a seven to ten day period. This requires some planning and foresight so that changes can be made before certain supplies of roughages run out.
Horses may have more energy when reducing hay intake and increasing the levels of other feed. This is why it is important for a competent Equine Nutritionist to take a look at the energy intake your horse was receiving and what the energy intake will be in your proposed diet. Horses fed a minimum amount of roughage may need more exercise time. Horses may need to be fed more often to reduce the times between meals thus preventing long periods of boredom and long periods of reduced gut fill. In many cases the total of feed fed will be reduced, therefore, the horse spends less time eating. When limited amounts of roughage are fed to horses you should be looking for signs of behavior changes. For example, some horses will begin the practice of coprophagy (eating their own feces). Another potential behavior problem is mane and tail chewing. Finally, horses may begin to crib. Cribbing is the act of a horse grabbing a horizontal surface, usually wood, with its incisor teeth, flexing their necks, and swallowing air. Physical problems may result from each of the motions a horse goes through during the act of cribbing. The incisor teeth become very badly worn, the neck muscles may develop excessively (hypertrophy), and if enough air is swallowed, colic may result. It is important that if you begin noting any of the above behaviors, that you make some changes immediately. Changes to be considered should be diet, less confinement time, more contact with other horses, and increasing the number of times a day a horse is fed.
To conclude, there is a limited supply of hay available for feeding horses. There are some alternatives to feeding horses with a limited amount of hay. A higher level of management is needed when feeding zero or limited amounts of hay to prevent digestive and behavioral problems. If you are not certain what you are doing, seek help from a competent Horse Nutritionist.