Question

I have two Quarter Horse broodmares, one 11 and one 17 years old. Both are reining-bred, and both are easy, easy keepers. Can I feed them all-they-can-eat alfalfa hay?

Answer

The short answer is yes, it is perfectly acceptable to feed your mares alfalfa hay. If the hay is moderate quality or better, your mares will likely have no trouble maintaining their weight.

If alfalfa hay is exceptionally more expensive than good-quality grass hay, as it is in some regions, and you’d like to save money on your feeding program, you may consider switching to grass hay. Steer clear of fescue, though, as broodmares could experience problems if the fescue is infected with a certain fungus. Mares such as yours, with the breeding and body type you describe, often maintain condition easily on grass hays.

The downside to free-access alfalfa hay for easy keepers is the potential for obesity. While there is no evidence to suggest that obese mares have more trouble foaling than thinner mares, any excess weight, especially when it is carried over many years, can have a negative effect on soundness. Plus, feeding to maintain obesity is harder on the wallet! Mares should be kept in moderate to moderately fleshy condition throughout all stages of production. Mares that were retired to the broodmare band for soundness reasons should be carefully and consistently monitored for excessive weight gain.

While good-quality forage will often supply the energy pregnant mares require, it will not provide all of the vitamins and minerals needed for optimal health of them and their unborn foals. To round out a nutrition program for pregnant mares, either (1) feed the minimal amount of a well-fortified feed intended for broodmares as recommended by the manufacturer, or (2) offer a balancer pellet or vitamin and mineral supplement to top off her diet. Your mares sound as though they might benefit best from the latter suggestion. Whether you choose to continue feeding alfalfa hay or switch to a grass hay, be sure to augment the diet with a trustworthy source of nutrients.

As a final note, it never hurts to go over any changes to a diet with an equine nutritionist, just to be sure no nutrient is under- or overfed.