If you caught yesterday\’s MSL (Bringing the Broodmares In), you\’ll know we\’re on a bit of broodmare care kick these days! And the timing is good, since Spring is (hopefully) on its way and foaling season is right around the corner. If you have broodmares and you need time to make some changes to their management and upkeep, now is the time to do it!
Today, let\’s talk a bit about broodmare nutrition.
It used to be thought that nutrition for pregnant mares was the same as a horse at maintenance for the first 2/3 of her gestation. This was because it is a well-known fact that fetal growth occurs at great rates in the last trimester (therefore an increase in energy and protein is always recommended during this time).
However, more recent studies are coming to light that suggest in addition to increased protein and energy in the last trimester, a pregnant mare should also have certain vital nutrients increased long before the 9th month. Keep in mind that the foal still gains approximately 0.5 lbs a day in the first 2/3 of gestation.
The publication of the National Research Council\’s latest revision of Nutrient Requirements of Horses now recommends that broodmares be fed the same as a horse at maintenance up to month 4, and every month after that should be treated as a separate \”period\”, meaning there are 8 distinct periods in her pregnancy. And her needs during this time are not usually met by forage alone – she will require additional supplementation.
The thinking behind this theory takes into account the nutritional requirements for the creation and maintenance of gestational tissues such as the placenta and mammary glands, in addition to the mare\’s body weight and fetal growth.
To support development and maintenance of nonfetal tissues, Nutrient Requirements of Horses recommends that protein and energy requirements be raised 5 to 8% above maintenance during midgestation for an average (500-kg) mare (see chart). Unlike protein and energy, the requirement for additional minerals seems to appear later in the gestation, at approximately seven months.
This can be attributed to the fact that nonfetal tissues require mostly protein and energy and very few minerals for accretion and subsequent maintenance.
In the last trimester (last 3-4 months) however, there is maximum growth of the foal. As such, the mare\’s nutritional requirements increase greatly (protein requirements go up to 12-13%). And they increase again for lactation (protein requirements go up to 14-16%).
The broodmare should be consuming 2-2.5 lbs of hay per every 100 lbs of her bodyweight, every day. And this consumption should increase accordingly with her gaining weight. The hay should be good quality, alfalfa mix. She will also require a concentrate / supplement to ensure her energy, vitamin and mineral requirements are being met (Vitamin A is especially important for broodmares). Be sure to introduce concentrates into their diet slowly! If you have not already started your mare on a supplement / concentrate early on in her pregnancy, now is not the time to start her on full scoops!! Check with your veterinarian for a feed recommendation and feeding dosage for your specific circumstance.