Management of the Broodmare

Adapted and shortened from “MARE AND FOAL NUTRITION. Feeding Management of the Broodmare” by Dr. Bob Mowrey, North Carolina State University.

One of the most important parts of managing a mare so she can produce a foal is nutrition. Mares can be broken down into three management groups: 1- open mares pre-breeding 2- pregnant / gestating mares and 3-lactating mares. In this article, we will discuss several different nutritional points on how to properly feed your broodmare.

Open and Maiden Mares

An open mare is a mare that has foaled in years past but did not conceive during the current season. A maiden mare is a mare that has never been bred. Horse owners should not feed open and maiden mares together; their nutrient requirements are totally different. For example, the maiden mare’s requirements are much higher (than an open mare) because she is still growing. An incorrect feeding program for either open or maiden mares can cause decreased growth, decreased pregnancy rates, and decreased fertility in maiden mares. Make sure you have a way to separate the two groups of mares in your pastures.

Open Mares – Horse owners can feed maiden mares the same diet they would feed a mature horse at a maintenance level. Good quality pastures need to be present and will likely meet the nutrient requirements for a mature open mare’s nutrient requirements.

Maiden Mares – They require a more nutrient-dense diet based on their body weight. Their diets must be supplemented with concentrates to meet protein, vitamin, mineral and energy requirements. Since maiden mares are still growing, calcium and phosphorus (minerals) are very important. Typically, good-quality pastures and high-quality hays are not enough to satisfy their nutrient requirements.

Body Condition

Mares that are a moderate to fleshy body condition score have been found to have reproductive efficiency similar to those in thrifty condition and actually rebreed more efficiently. Mares that have a higher body condition score do not need as much feed during lactation. This reduces feed costs as well as colic and founder. It is less of a health problem for maiden and open mares to have excessive fat deposition than it is for them to have a nutrient deficiency. Thin mares will supply their own nutrient requirements before their body will meet the needs of their foal. If there is a severe nutrient deficiency, the mare could possibly abort and have breeding problems in the future.

 

Preparing Open mares for Breeding

Mares that have an adequate body condition are able to have better conception rates. Body condition of a mare can be altered by changing their energy intake. For an excessively obese mare you can exercise the mare, reduce grain intake, increase levels of protein, vitamins and minerals in grain, or try a dry lot.

Feeding the Pregnant Mare

These mares are typically grouped into two categories: 1- mares in their first two trimesters and 2- mares in their last trimester of pregnancy. The foal does not grow rapidly during the first eight months. However, during the last trimester, the foal is rapidly growing and needs additional nutrients from the mare. Be careful with the amount of copper found in the mare’s diet in late pregnancy. Research has shown mares in late pregnancy whose diet contains copper may have an affect on foal bone development.

Fescue Toxicosis

During the mare’s last semester, they should be removed from areas that contain fungus-infected fescue hay and pasture. When mares are in their last trimester and are allowed to graze this type of pasture, they will likely have severe complications during foaling. If you are concerned your fescue pasture contains endophyte-infected fescue, you can sample your forage and send it to the North Carolina Department of Agriculture to be sampled. There is a small fee for this.

Nutritionally Managing a Lactating Mare

Their nutrient requirements are already elevated and will increase during lactation. The mare must consume additional nutrients to make up for this increase. Also, during the first 30 days of lactation, the foal’s nutrient requirements drastically increase. It is important to reduce as much stress on the mare as possible during this time, as they are experiencing nutritional stress as well as psychological stress. Make sure to take equally as good of care with your foal’s nutrient requirements and health once it’s born!

For more information on feeding management of broodmares, contact Margaret A. Bell at the Craven or Jones Counties Cooperative Extension Office at (252) 633.1477.