Q: My senior horse is missing most of his teeth and cannot eat hay like he used to. How can I make sure he has enough fiber in his diet now that he eats pellets? Will he still be able to get all the essential nutrients through the pellets?
A: Horses’ teeth are interesting because they erupt over their lifetime similar to lead in a mechanical pencil. The tooth gets worn down but more erupts until eventually there is no more lead in the pencil. Senior horses with few or no teeth find hay-based diets challenging because they do not have the ability to grind the longer stemmed pieces of hay into the small particles they would have created when their teeth were more functional.
An inability to chew forage properly has multiple implications. Obviously, if hay is not being ground down into small enough pieces, the horse is at increased risk of impaction colic. Larger poorly chewed hay pieces might also irritate the intestinal lining, leading to inflammation in the gut lining and colitis (inflammation of the colon). Finally, larger pieces of hay are not digested as well due to their relatively smaller surface area, giving digestive enzymes and hindgut bacteria less room to work.
Substituting long-stem hay with hay pellets is one solution for senior horses. The hay has been chopped into tiny pieces and then reformed into a pellet, forcing it through a piece of machinery called a die under heat and pressure. For horses with no teeth, it is generally recommended that these pellets be soaked prior to feeding so that they disintegrate back into the tiny chopped pieces, reducing the risk of choke.
The particle size of chopped hay is far smaller than that of properly chewed hay when the horse has functional teeth. This greatly increases the relative surface area and often results in greater feed utilization due to improved digestion. This can also be very helpful if your horse struggles to maintain weight.
Fiber is a collective term for several carbohydrate fractions found in various feeds. Some of these carbohydrates, such as hemicellulose, are quite readily fermented and broken down by the hindgut microorganisms. Other fiber fractions, such as lignin, are not. If you take a bale of hay and convert it into hay pellets, the fiber content is the same because fiber is something that exists at a cellular level. The fiber in hay pellets might in fact be more available to the horse due to the possibility of better microbial attachment and fermentation than when it is in its original hay form.
The greater issue is the fiber’s form. Horses typically eat hay pellets faster than hay, which might lead to boredom. They also result in less gut fill and might stimulate the gut lining less. In ruminant animals such as cows, “scratch factor,” as it is known, is important for maintaining a healthy rumen lining. Our knowledge of the importance of long-stem forage on the physical health of the equine hindgut is less well known. However, pellets will not result in the same quality of fiber mat being made in the stomach, and the reduced chew time means less saliva production and less ability to buffer stomach acid. Therefore, horses fed exclusively pellets might be at greater risk of developing gastric ulcers, so feeding the daily pellet quota in as many small meals as possible throughout the day important.
Feeding special needs horses is often an exercise in risk management. While it might be advantageous to feed some amount of the forage as long-stem hay for gut health purposes, if your horse’s teeth are at a stage that this could result in choke or impaction colic, then it’s something to avoid. You might need to accept the possibility that your horse’s chosen diet could increase his risk of other health concerns.
As far as providing all essential nutrients, it is very unlikely that a straight hay pellet will achieve this, which is also true of long-stem hay. Forages are typically too low in trace minerals such as copper and zinc, vitamins such as vitamin E, and sometimes quality protein to meet the horse’s needs.
If your horse can be maintained solely on hay pellets, then adding a quality ration balancer is recommended. However, if weight maintenance is a struggle when feeding only hay pellets, a properly fortified complete senior feed might be a better solution. Complete senior feeds are typically formulated with ingredients that are more readily digestible and might contain more fat to help maintain condition.
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