Horse Breeding: Mare Nutrition

Horse Breeding: Mare Nutrition

AQHA Corporate Partner Nutrena answers frequently asked questions about broodmare nutrition and feeding for healthy foals.

broodmare and foal running (Credit: Jeni Dieringer)

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Are you looking to understand more about breeding and nutrition? Feeding the broodmare properly can help reduce the risk of developmental problems for the foal and help insure that the mare can be rebred in a timely manner to produce another foal the following year.

Here we answer some frequently asked questions when it comes to breeding your horse and how nutrition plays a factor in overall broodmare and foal health.

Foaling season is an exciting time of the year! Tag your social media posts with #AQHAfoals so we can see the newest additions to your herd. Follow us on Facebook and Instagram to join the celebrations.

Is there a time in a broodmare’s gestation period to focus more on nutrition? 

The latter part of gestation is one of the most important development periods in the life of a foal when the foal is developing in the uterus of the mare. Nutrient requirements of the mare start increasing at the sixth month of gestation, earlier than previously believed. During the last three months of gestation, the foal may be gaining an average of one pound per day.

Foals should be growing each day, and we would love to see them grow with you! #AQHAfoals on Facebook  and Instagram  to share their progress with us.

What is an appropriate body condition score for a pregnant mare?

Mares should be at about a body condition score of 6 when they foal and throughout lactation so that they have sufficient energy reserves for milk production as well as to maintain proper condition for re-breeding.
What are amino acids and why are they important?

Lysine, methionine, and threonine, the first three limiting essential amino acids, need to be sufficient in the diet for placental and fetal development, plus they are critical for milk production after foaling.

What minerals are needed for pregnant mares?

The mare should receive adequate calcium, phosphorus, magnesium, copper, zinc, manganese and selenium to provide minerals for the development of the foal and to build the foal’s own trace mineral reserves. Trace minerals including manganese, selenium and zinc are also critical for immune support.

Is it safe to vaccinate and deworm pregnant mares?

A regular vaccination program should be developed in conjunction with a veterinarian so the mare is protected and can also produce the appropriate antibodies to protect the foal when it nurses and receives the colostrum that contains maternal antibodies.  This is what protects the foal until it can be vaccinated and develop its own antibodies. The mare should also be dewormed as needed prior to foaling.

Baby foals are precious, and we want to see them! #AQHAfoals on Facebook and Instagram to share your new babies.

My mare is sustained only on hay and pasture. Does she require any concentrated feed while pregnant?

Good quality pasture or forage may provide sufficient energy thru late gestation, but may NOT provide adequate amino acids and minerals for optimal fetal development. A well-designed ration balancer product may be used throughout gestation to provide the missing nutrients. During late gestation and especially just before foaling, a higher calorie feed for broodmares and foals should be introduced so that the mare is on the feed before she foals to avoid the need for a sudden change in feed. This feed can then be increased after foaling to provide both the increased energy and nutrients that are required for lactation, as well as providing nutrition for the foal when it starts to nibble on feed. Fresh clean water and free choice salt should also be available at all times.

My mare is not cycling as expected. What can I do to help this process along?

The use of artificial lighting to help prepare mares for breeding is a fairly standard management tool. A common practice is to put mares under lights in early December to help get mares cycling by mid to late February. Breeding earlier than mid-February is not recommended as a short gestation period might result in a December foal and a very young yearling! There are multiple lighting systems, but all deliver 16 hours of combined artificial and natural light. While you can use a light meter to measure illumination, a common rule of thumb is that you should be able to comfortably read a newspaper in any of the stall or paddock area when the lights are on. However, if you have mares that are due to foal very early, you may want to avoid putting them under lights as this has been reported to shorten gestation a few days. 

Should I worry about my mare’s body condition prior to breeding?

If you have open mares that are below Body Condition Score 5, now is a good time to increase the plane of nutrition so that they are maintaining or even gaining a slight bit of weight. If they are over BCS 6, do not put them on a diet as a negative energy balance (losing weight) may interfere with their normal estrus cycle.

Although breeding horses is not always the easiest endeavor, with proper veterinary care, artificial lighting and good nutrition, you can set the stage for a successful breeding program.

For more information on mare and foal nutrition, visit and