Nurturing Pregnant Mares: A Vital Journey

The last six months of gestation for a mare are a critical period for the development of her foal within the confines of her uterus. This pivotal stage in equine reproduction was underscored in the Nutrient Requirements of Horses, Sixth Edition, where it was established that the nutritional needs of the mare begin to increase at the onset of the sixth month of gestation. For mares that have recently foaled or were bred within the first four months of the year, they may now be approaching this crucial six-month milestone, making it an opportune time for a comprehensive fall check-up.

Managing a pregnant mare effectively involves several key components:

Confirm Pregnancy: It is imperative to verify the pregnancy status of all bred mares. If there are open mares this period offers an ideal opportunity to identify any potential issues and prepare them for breeding in the upcoming season. If a mare was previously pregnant but has lost the pregnancy, this is the moment to strategize her future breeding plan. For those requiring additional light exposure for optimal breeding conditions, this should commence around December 1. If body condition was a concern, now is the time to ensure she attains the desired score.

Body Condition: Mares should ideally maintain a body condition score of 6 during gestation to ensure they possess sufficient energy reserves for early lactation and to retain condition for re-breeding. If a mare needs to gain weight, the current period presents an excellent window to gradually increase her energy intake, enabling her to attain the desired body condition at foaling. Conversely, if a mare carries excess weight, a modest reduction in energy intake or an increase in exercise may be considered, while ensuring adequate amino acids, vitamins, and minerals are provided for the developing foal. Extensive weight loss is not recommended.

Essential Amino Acids: Lysine, methionine, and threonine, the foremost three essential limiting amino acids, must be adequately present in the mare’s diet to support placental and fetal development. These amino acids bear greater significance than crude protein content.

Mineral and Vitamin Intake: Mares require a balanced intake of calcium, phosphorus, magnesium, copper, zinc, manganese, and selenium to provide the essential minerals necessary for the foal’s development and to establish the foal’s own reserves of trace minerals. These trace minerals also play a pivotal role in bolstering the immune system. A comprehensive vitamin program is equally indispensable.

Healthcare Regimen: Collaborate with a veterinarian to formulate a regular healthcare program. This not only safeguards the mare’s well-being but also facilitates the production of maternal antibodies critical for the foal’s immunity, particularly when it nurses and receives colostrum.

While high-quality pasture or forage may meet the energy requirements during late gestation, it is unlikely to supply the necessary amino acids, vitamins, and minerals. An appropriate ration balancer product can be introduced from the fifth month of gestation until around the tenth or eleventh month to bridge these nutritional gaps. A specialized feed tailored for broodmares and foals may be incorporated prior to foaling, ensuring that the mare is on the feed before giving birth. Post-foaling, this feed can be escalated to accommodate the increased energy and nutrient demands necessitated by lactation while also providing nourishment for the foal when it begins nibbling on feed. Access to fresh, clean water and free-choice salt should always be accessible.

Feeding a broodmare diligently during gestation not only mitigates the risk of developmental issues in the foal but also paves the way for timely re-breeding, allowing the mare to produce another foal in the ensuing year.

By Staff writer