16 Dec 2015

Broodmare Pregnancy & Nutrition

0 Comment

It’s getting close to that time of year. Please review our recommendations for broodmare nutrition and health. Hoping for a healthy foaling.


  • Pre-breeding – a body condition score of 5.5-6.5 of 9 is ideal and represents the optimum condition score on the Henneke Scale from 1-9 if you are at the stage of preparing your mare for breeding
  • Total daily feed intake by mares (hay + concentrate ) normally ranges from 1.5-3.0 % of their body weight with 2% being average

Early To Mid Gestation

  • In the first 8 months of gestation your mare will likely have the same nutrient requirements to those of any mature, idle horse. When looking at the feed tag, be sure to feed by these requirements, typically. Consult your veterinarian if you have questions.
  • The developing foal gains only 0.2 pounds/day during this stage, thus not a significant nutritional demand on your mare
  • When feeding, simply meet the mare’s nutrient requirements for maintenance.
  • Research shows that mares fed insufficient protein diets (ie., 8.6%) did have lower serum progesterone concentrations compared to mares fed higher protein diets (ie., 17%)
  • If your mare’s diet is simply based on pasture, you are likely not meeting her mineral needs. Mineral supplementation is accomplished with a free-choice loose mineral (Purina free balance horse mineral) or mineral block for horses. A trace-mineralized salt block will not provide sufficient mineral needs to meet these requirements.
  • If you are feeding moderate to poor quality hay, you will need to provide additional supplementation. A quality concentrate feed at 0.5-0.75 % body weight will keep the mare in good shape and support nutritional requirements at this stage. Feed according to her body condition.
  • Easy keeper mares that can be maintained at a body condition score of 5-6.5 of 9 on hay or pasture alone then consider a ration balancer pellet (ie., Purina Enrich Plus) to provide protein, vitamins and minerals. Consult your veterinarian for a feeding rate. This option is more controlled nutrition and support then a free-choice mineral.
  • Mares that need extra calories to support body condition of 5-6.5 of 9 can be given one of the following concentrates – Purina Strategy GX, Omolene 200, or Ultium Growth.

Broodmare Pregnancy & Nutrition

Late Gestation

  • As your mare enters the last 3-4 months of gestation the unborn foal is growing more rapidly (about 1 pound per day). The intake of protein, energy, vitamins and minerals should be increased for your mare over time.
  • Mares at this stage should receive a quality concentrate supplementation
  • Forage may provide sufficient calories to maintain body condition, but other nutrients particularly protein and minerals will be inadequate.
  • Research has shown that foal birth weight can be adversely affected when mares do not receive adequate protein during late gestation even if your mare is at an acceptable body condition score of 5.5-7.5.
  • If your mare is overweight, calorie restriction may be needed for her at this stage (see below for nutrition in an overweight mare).
  • During the 10th month, the greatest mineral retention occurs in the foal. Adequate mineral nutrition of the mare is critical for fetal development.
  • Vitamin E can be supplemented at this stage (ie., Elevate WS to be fed per label for the pregnant mare) to result in a greater IgG and IgA concentration in colostrum which will later get passed on to the foal in the form of maternal immunity. Recommended at 800 IU Vitamin E per day for an 1100 pound mare.
  • If your mare is in unsatisfactory condition, consult your veterinarian about adding supplemental fats or oils to the diet, which are more energy dense
  • Gradual feed intake and feed volume should increase prior to foaling because nutritional demands will double at lactation and this abrupt change should not occur on the day of foaling.
  • For all mares (other than significantly obese mares) should be transitioned to the same feed they will be fed during lactation such as – Purina Strategy GX, Omelene 300, or Ultium Growth along with good quality hay or pasture.
  • Be sure to increase feed volume gradually by an average feed rate of 1-1.5 lbs per month for each of the last 3-4 months of gestation. This will provide nutritional support for the growing fetus and prevent a drastic feed volume increase at the time of foaling.
  • Significantly overweight mares – should be maintained on Purina Enrich Plus, increasing to 2 lbs per day in the last three months of gestation.

Broodmare Pregnancy & Nutrition


  • Once your mare foals, the nutrient demands increase significantly. The protein and energy requirements almost double. In addition, requirements for calcium, phosphorous, and Vitamin A increase too. This is a critical nutrition period for your mare.
  • Maintain a body condition score of 5-6 out of 9
  • There must be an increase in the plane of nutrition leading up to lactation as to not make any abrupt feed volume requirements at the time of lactation
  • If you underfeed at this stage your mare will have poor milk production, and weight loss may occur. Monitor your mare’s body condition score with your veterinarian using the Henneke scale
  • Mares produce and average of 24 pounds of milk daily during a 5 month lactation. High producing mares can read 32 pounds of milk /day
  • The average milk production in the first 22 days for a mare is 26.5 pounds of milk per day and milk production appears to peak at 30 days post foaling.
  • A lactating mare will usually consume between 2 and 3% of her body weight in total feed (hay and concentrate) per day
  • All lactating mares need free –choice good quality hay or pasture and then access to a concentrate such as Purina Strategy GX, Omelene 300, or Ultium Growth.
  • Hard keeper lactating mares – Ultium growth would be the best choice at this stage for mares that are difficult to maintain condition through lactation as it provides the highest calories per pound.
  • Continue with Vitamin E supplementation feeding at a rate of 1,000 IU per day for an 1100 pound mare.

Vaccinations For Your Pregnant Mare–

Pneumabort K – 5, 7 and 9 months. You may also consider vaccinating at month 3. Consult your veterinarian for recommendations based on your mare’s situation

Eastern and western encephalitis, tetanus, and west nile virus – month 10 of gestation

Rabies – to be given before breeding or after foaling

Rotavirus and Botulism – a risk based vaccine. Discuss with your veterinarian if your mare is at risk and should be vaccinated based on your mare’s situation.


**Feeding recommendations were made based on the recommendations of Purina Equine Nutritionist, Dr. Karen E. Davison.

**Vaccination recommendations were made based on the recommendations of the American Association of Equine Practitioners.

Written By: Dr. Gina Tranquillo

%d bloggers like this: