Skip to content
Search Library
thumbnail

It is common, though most often incorrect, to attribute many fertility problems in the broodmare to vitamin deficiencies. This approach neglects the single most important nutritional variable in reproductive efficiency: energy balance. More progress can be made in terms of increasing conception rates by ensuring appropriate body condition than by using any other nutritional tool. This is not to say that meeting vitamin, mineral, and protein requirements is not important, but from a practical standpoint, energy balance tends to be more of a concern. There is no reason to assume that any species of animal is designed to conceive, carry a pregnancy to term, and rebreed while in a negative energy balance.

Broodmares should be kept in reasonable flesh throughout the year, with owners practicing “straight line” broodmare nutrition. This means that an optimum condition should be established for each mare and appropriate adjustments made in the feeding program to maintain this condition. Coming into the last trimester of pregnancy, the mare should begin receiving more feed in preparation for lactation. Likewise, feed intake should be increased during lactation to support the production of milk without excessive loss of body condition. During the final half of lactation, the energy intake of the mare should be adjusted depending on her body condition at that point in time and on forage availability, again in hopes of maintaining optimum condition.

Once a foal is weaned and the mare dries up, an assessment of condition should be made and this period should be used to adjust the mare’s condition back to optimal. For a heavy-milking mare that has gone through a tough lactation, owners might want to continue to feed her at preweaning levels of feed intake to allow her to gain condition. Mares that are fat may not need extra grain as they can meet their energy needs on good quality forage alone. These mares should not be allowed to become too thin, as mares that are slightly plump are more reproductively efficient than are mares that are underweight.

For barren and maiden mares, the plane of nutrition should be increased as the breeding season approaches. It makes good sense to increase nutrient intake when mares are put under lights so that an increase in condition is achieved at the same time as an increase in day length. This practice is referred to as nutritional flushing, and it is effective in shortening the transitional period and increasing conception rates. For mares that will be bred in February and March, it mimics what would naturally occur later in the spring when lush grass would result in increased body fat stores.

Poor conformation of a mare’s external genitalia is often as much a function of body condition as anything else. Thin mares are especially prone to sunken vulvas that are apt to result in fecal contamination or windsucking (pneumovagina). Especially in older mares, adding body weight may improve conformation and hence reproductive performance.

Another nutrient related to reproduction is selenium. Research at Cornell University showed that mares receiving inadequate selenium were much more prone to reproductive problems than were mares receiving adequate selenium.

X

Subscribe to Equinews and get the latest equine nutrition and health news delivered to your inbox. Sign up for free now!