Recap
Before we explore the nutrient requirements for late gestation let’s do a quick recap:
Body Condition
Maintaining an ideal body condition of 5-6 on a scale where 1 is extremely emaciated and 9 is excessively obese, is essential in maintaining a healthy pregnancy, developing a strong foal and supporting the mare. Monitor your broodmare’s body condition before during and after pregnancy and make necessary adjustments to her diet to fulfill all her energy and nutrient requirements through the various stages.
Forage First
The foundation of your mare’s diet should be high-quality forage; in which, she should be consuming roughly 2% of her body weight a day. In order to know what your nutrients your forage is providing and what it is lacking, be sure to have your hay tested. The results will guide you to what additional supplementation you need to provide in her diet.
Avoid Tall Fescue
Fescue grasses are known for containing a toxic bacteria or fungus called endophytes. These endophytes play an important role in the hardiness and integrity of the plant. While all plants have endophytes, not all endophytes are toxic to pregnant mares. The endophytes found in fescue grasses, however, typically are infected with the toxins. Therefore, especially during late gestation, it is crucial to keep your broodmare from consuming pastures or hay containing tall fescue, unless the fescue is a novel endophyte variety that has been specifically developed to be non-toxic. Contact your veterinarian, nutrition specialist or local Ag extension if you have any questions or concerns in identifying tall fescue in your forage.
Balanced Diet
Be sure to have each new batch of hay tested to determine what nutrients she is receiving from her forage and what is lacking. With the knowledge gained from those results you will have clear direction in what extra nutrients you need to provide in her daily diet.
Water and Hydration
Keeping your mare well hydrated throughout her pregnancy is key to maintaining a healthy digestive track, aiding in the proper development of the foal, as well as, preparing for lactation.
Healthy Gut
Avoid high-sugar feeds and long, time gaps without forage. Frequent, smaller meals, plenty of water and keeping her environment calm and predictable all help to maintain a healthy digestive system.
For a deeper dive into the above topics, please refer to the previous 2 articles in this Gestational Nutrition Series.
What More to Expect During Late Gestation
While there are number of consistent expectations and requirements to meet throughout your mare’s entire pregnancy, the last 90 days before foaling is, typically, when energy and nutrient requirements skyrocket. Here are some things to prepare for during late gestation that may be different than earlier in the pregnancy.
Drastic Increase in Calorie and Nutrient Intake
As the developing foal grows larger and the mare is preparing for lactation, her energy and nutrient requirements increase drastically. All incoming calories and nutrients will be pulled from the mare to support the needs of the foal, first and foremost. So, it is crucial to provide her with enough of the right nutrition sources to keep her own body from depletion. The key is to provide her with all she needs without over doing it.
The goal is to keep the mare at a 5-6 body condition score on a scale where 1 is extremely emaciated and 9 is excessively obese. This will require a keen eye that is evaluating her body condition daily. As long as the mare is consuming a balanced diet of roughly 2% of her body weight a day in high quality forage that is offset by a diet balancer and/or a high fat, high fiber fortified feed with a guaranteed low sugar and starch content, the likelihood that her needs are being met are good. However, it is important to choose a diet balancer and/or fortified feed that have been designed for late gestation mares. You will know this by reading the feeding instructions on the tag/bag; by whether the manufacturer has provided feeding instructions specific to late gestation mares. Note: It is not uncommon for mares during the last 2-3 months of gestation and during lactation to require up to 20% (give or take) more calories above maintenance guidelines. Again, this is going to take an observant eye to watch the mare’s body condition and adjust appropriately to maintain a 5-6 body condition score.
Creative Ways to Increase Calorie and Nutrient Intake
During the last 2-3 months of pregnancy, the foal is growing bigger and bigger. As the foal takes up more and more space in her belly, it can lessen the normal space for her digestive tract. Consequently, she may experience some discomfort. Any discomfort on top of the limited space for copious amounts of forage and feed material can present a challenge. While you want to keep drastic changes to a minimum, you may need to get creative with ways to get the most nutrition into a lesser amount of feed material. Here are some things to consider:
- If not already on a diet balancer, get her started on one. Diet balancers are great for providing her daily requirements of vitamins, minerals and amino acids in a low feeding rate.
- Add an oil or fat supplement to her diet balancer and/or feed to give her an extra boost of calories.
- Replace some or more of her grass hay with a high-quality legume hay, like alfalfa. Legumes tend to have a higher caloric density, while also boosting a lower sugar and starch content than that of grass hays. They also provide more calcium which is beneficial as she is preparing for lactation and, also, provides a little more of an acidic buffer in her gut.
- If able to manage consistently, increase the number of times a day that she is fed. This breaks up her daily ration into smaller and more manageable amounts to consume. The slow and steady trickle of feed throughout the day and night can encourage her to keep eating. Whereas, large meals offered just a few times a day can be overwhelming, causing further discomfort; which, in turn, can slow her down or back her away from eating all that she needs because she is trying to avoid the discomfort.
- If your mare is turned out with other horses, separate her out for feeding to ensure she is not having to fend for her portion. When your mare is already exhausted and uncomfortable, especially if she is not high in the herd pecking order, giving her a safe space to eat in peace can be helpful.
- Provide free-choice access to salt and mineral. Monitor her use of this and adjust as necessary. Some mares will avoid it, others will consume in moderation, while others will scarf it down. As long as she is not over consuming the salt and mineral, what she does take in can increase her thirst and encourage her to drink more. Always keep easy access to fresh, clean, drinkable water.
Common questions regarding feeding a mare during late gestation.
When during pregnancy will my mare need more nutrition?
Typically, during the last 60-90 before foaling is when she may have the biggest surge in energy and nutrient requirements. However, it is important to monitor your mare’s body condition throughout her entire pregnancy and make dietary adjustments as needed to keep her in ideal condition.
How do I feed my mare during the last few months before foaling?
How you feed your mare during the last few months before foaling will be directed by her body condition. You do not want to over nor under feed her. However, during the last leg of her pregnancy, while the foal is developing and growing rapidly and her body is preparing for lactation, she will likely require a substantial boost in her caloric and nutrient intake. The base of her diet should be high quality forage. Adding a diet balancer will help to ensure she is getting all she needs to meet her daily vitamin, mineral and amino acid requirements. A commercial feed that is high in fat and fiber and low in sugar and starches will provide added calories/energy. (Whatever feed or balancer you use, make sure that the product has feeding instructions on the bag or tag specific to late gestation broodmares.) Provide access to fresh, clean, drinkable water at all times and consider offering free choice salt and mineral. Consult with your veterinarian or equine nutritionist for guidance and support if you have any questions or concerns.
Do I still need to keep my mare off tall fescue during late gestation?
Absolutely, yes! The endophytes (fungus/bacteria) that are found in tall fescue, if not the novel version, are toxic to pregnant mares. The problems it can cause to the pregnancy and developing foal can be catastrophic; and are most commonly linked to consumption of these toxic endophytes during late pregnancy.
What would happen if I do not make any changes to my mare’s diet during the last few months of her pregnancy?
There are certainly a lot of variables to be considered; so unfortunately, there is no blanket answer. Ultimately, your mare’s body will prioritize the needs of the developing foal over herself. If she is not supported with adequate nutrition and calories, her body and body condition will be the first to be depleted. Next, if the growing foal requires more nutrients than is available through the mare, the foal may not develop properly. All these things can lead to an unhealthy mare, an unhealthy pregnancy and/or birth, the inability for the mare to produce enough milk to support the foal once it’s been born and/or developmental problems for the foal that could affect its entire life. In addition, if the mare is nutritionally depleted and in poor condition the chance of her taking to a rebreed decreases rapidly.
