Whether you are a new to horse breeding or are an experienced breeder, it is crucial to understand the importance of properly caring for your pregnant mare to ensure for a safe and healthy birth for both mother and foal.
Let’s face it — while this is an exciting time, it can be very stressful. Even the most experienced breeders have questions that come up.
To successfully care for your pregnant mare while minimizing the stress it can have on you, it is helpful to have some guidelines to follow.
Before you consider breeding your mare, there are things that should be taken into consideration.
Body Condition Scoring
A universal method to measure weight and fat distribution, called body condition scoring, has become one of the most effective tools used by breeders.
The vague terms “hard keeper” or “fatter than a county fair hog” are no longer relevant when considering a mare’s breeding readiness.
When you are considering breeding your mare, studies have shown that mares with a body condition score of 5, 6, or 7, have over a 90% higher chance of getting pregnant than those with lower or higher scores.
The Current Nutrition and Gut Health of the Mare
Mares are expected to carry a healthy foal for 11 months and produce enough milk for that foal for at least 6 months. Therefore, it would seem logical how critical a role nutrition plays in breeding.
Nutritional management, in many ways, determines the success of breeding in the mare due to the influences it has on the various cycles of production.
Good nutrition doesn’t just involve feeding the right kinds of feed. It also is highly dependent on the mare’s ability to properly digest and absorb nutrients.
A low pH can result in a whole range of issues, including poor absorption and ulcers. When the pH is low, the gut flora can become unbalanced, with a die-off of beneficial microbes and an explosion of the pathogenic flora. When this happens, a horse’s ability to properly digest and utilize nutrients is compromised.
Then we come to ulcers. Gastric ulcers are more prevalent among broodmares than you might expect. According to one study, an alarming 70.9% of the mares included had gastric ulcers. The pain caused by these ulcers can lead to a decrease in feed consumption and stress, raising overall cortisol levels.
When Was the Last Foal Born?
Surprisingly, the reason to consider this is similar as to with humans. The mare’s gestation period lasts approximately 11 months, and then mare will nurse its foal for approximately 6 months. The general rule for mares (and for humans for that matter) is to allow the mare to have the appropriate time for her cycle to normalize. This will optimize the mare’s chances of a successful breed-back and pregnancy.
Consider the Mare’s Age
The age at which a mare can breed and should be bred are two different things. A healthy mare will start cycling, can be bred and even become pregnant in their yearling spring, often before their first full year of life.
Studies show that breeding fillies this early in life will frequently lead to a smaller foal and less milk production from the mare. It also may result in underdevelopment of the mare herself, as many of the resources she’d be using to grow are going to the development of the foal.
The general consensus within the horse/veterinary community has been to give fillies additional time to mature by allowing them to reach 3 years of age before breeding to successfully carry a pregnancy to term.
On the opposite spectrum, mares often will carry foals into their 20’s with no problem. However, it is now well documented that the eggs of mares over 18 years old have a very high incidence of inherent defects that result in a high rate of early pregnancy loss (20-30% or higher). Therefore, it is sometimes best to consider the health of the mare, rather than the age.
Conditioning for Breeding
Okay, so by now you have a general idea of what things to consider prior to breeding your mare. Now let’s discuss the next step, conditioning your mare for breeding.
Because mares are not the most fertile animals (conception rate is approximately noted to be 60%), in order to avoid frustration and excessive expenses there are things you can do to maximize a successful breeding.
Optimal health in your mare is essential to achieve the greatest reproductive efficiency. By being proactive you can take the necessary steps to attain this optimal health in your mare.
General health includes making sure your horse is in good physical condition. Your mare’s diet should consist of high-quality feed to ensure proper weight which directly can influence regular cycling of the mare. Equally as important is good dental health by having your mare’s teeth examined regularly. It is also recommended having your mare dewormed every 6-8 weeks.
Required vaccinations should be met prior to breeding your mare. It’s important to remember that vaccines are only as effective as the immune system is strong. If your mare has recently had an illness, injury or other stressors, you may want to wait to vaccinate until she has recovered.
There are different requirements depending on what region of the country your mare is living. Talk to your veterinarian about which vaccinations your mare will need to be covered in your particular area.