Understanding the pregnant mare’s nutritional requirements, and how best to meet them, is key for the health of both the mare and the developing foal.
When feeding the broodmare it is important to remember that the foetus does not grow at a constant rate throughout the entire pregnancy. During early and mid-pregnancy, the foetus is small, attaining only 20% of its birth weight, and hence its nutrient requirements are relatively low. Therefore, in the past it was thought that mare’s nutritional requirements did not increase until late pregnancy. However, we now know that this is not the case!
Feeding the Broodmare during Early Pregnancy
Over-feeding during early pregnancy is a common mistake, often resulting in the pregnant mare becoming overweight. Obesity can be a serious problem and may reduce fertility, increase the risk of problems such as laminitis and potentially predispose the foal to developmental orthopaedic diseases after birth. Ideally, during early pregnancy the mare’s condition should be maintained. Even for overweight mares weight loss is not recommended during the first 3-4 months of pregnancy as this has been linked to early embryonic loss plus, if the mare is simultaneously lactating, can result in reduced milk production. A body condition score between 3 out of 5 or 5 to 7 out of 9, depending on the system used, is considered optimal for a broodmare throughout pregnancy.
Nutritional Needs of the Broodmare during Early Pregnancy
Forage alone is unlikely to provide optimal levels, or the correct ratios, of all the essential micronutrients (e.g. copper and zinc) (Figure 1). Therefore, all broodmares will need a suitable hard feed for broodmares during early pregnancy. This will help to avoid the mare using her own stores and entering mid-late gestation with deficiencies. The most suitable ration will obviously depend on the individual. Mares that are lactating, poor doers or those with limited access to good quality forage will typically require a more calorie rich ration such as Connolly’s RED MILLS Stud Mix or Cubes.
Ensuring your Broodmare has Sufficient Nutrients in her Diet During Early Pregnancy
Alternatively, if straight cereals (e.g. oats) are being fed, we recommend our Connolly’s RED MILLS Oat Balancer Mix or Pellets, which have been specifically formulated to balance the micronutrient content of cereals, including the calcium to phosphorus ratio. On the other hand, a nutrient-dense feed balancer such as Connolly’s RED MILLS GROCARE Balancer, is an ideal balancer for mares & foals. Alternatively, a broad-spectrum equine vitamin and mineral supplement such as Foran Equine Chevinal Extra, is ideal for breeding mares requiring a calorie-controlled diet.
Energy Requirements of Broodmare during Mid-Pregnancy
Starting in the fifth month of gestation, foetal growth rate begins to increase, resulting in corresponding month-by-month increases in the mare’s nutrient needs. Therefore, the guidelines laid out in the 2007 National Research Council’s (NRC) Nutrient Requirements of Horses recommends that the calorie (energy) content of the diet be gradually increased starting at the 5th month of gestation. It is important not to oversupply calories and carefully monitor the mare’s condition in the second trimester. Although excessive weight gain is to be avoided, some weight gain during mid-gestation is necessary to provide an energy source for use in late gestation and early lactation.
Protein Requirement of the Broodmare during Mid Pregnancy
The requirements for protein, an essential nutrient needed to support foetal growth, also increases during the second trimester. Protein is made up of non-essential and essential amino acids (e.g. lysine and methionine). The latter cannot be made in the body and must be provided in the diet. The main source of quality protein in Connolly’s RED MILLS feed is soya, which contains excellent levels of essential amino acids. Raw soybeans naturally contain an anti-nutritional factor called trypsin inhibitor. Trypsin inhibitor is a compound that blocks the action of trypsin, an enzyme needed for protein absorption. At Connolly’s RED MILS, we use an advanced cooking technique known as extrusion to destroy the trypsin inhibitor, thereby ensuring that the horse can digest the quality protein they provide.
Vitamin and Mineral Requirements of the Broodmare during Mid Pregnancy
Unlike energy and protein requirements, the mare’s vitamin and mineral needs do not increase through mid-pregnancy and, provided the mare is receiving the correct amounts of a suitable hard feed, optimal levels of all the essential micronutrients will be provided in the overall diet.
The most suitable hard feed for broodmares in mid-pregnancy will depend on the time of year or more specifically the availability of good grazing. Mares grazing lush pasture or ‘good-doers’ may not require large amounts of hard feed. However, they will still require a source of essential micronutrients (e.g. copper for your mare etc.). Feeding a traditional stud mix or cube may prove too calorific so instead a high specification horse balancer (e.g. Connolly’s RED MILLS GROCARE Balancer) or equine multivitamin supplement (e.g. Foran Equine Chevinal) is ideal.
Pasture Availability Dictates the Amount of Hard Feed during Mid Pregnancy
On the other hand, mares that do not have access to sufficient high quality pasture or those prone to weight loss will generally need higher levels of concentrated horse feed. In these situations, Connolly’s RED MILLS Stud Mix or Cubes can be fed according to condition. Although, if fed at less than the recommended guidelines our horse feed balancer, Connolly’s RED MILLS GROCARE Balancer or our equine vitamin & mineral supplement, Foran Equine Chevinal should be added to the ration to ‘top up’ micronutrient intake. If needed, another excellent way of adding calories to the diet, and providing a source of beneficial omega 3 fatty acids, is to supplement with an equine oil supplement such as Foran Equine Kentucky Karron Oil.
Adjusting the Broodmares Hard Feed During Pregnancy
It is not uncommon for pregnant mare to simultaneously have a foal at foot and weaning usually takes place when the mare is in her second trimester. To facilitate drying up the mare’s concentrate feed will need to be tapered off. This will mean that any Stud Cubes/ Mix fed should be gradually reduced and replaced with an appropriate horse feed balancer for mares (e.g. Connolly’s RED MILLS GROCARE balancer) or a high specification vitamin and mineral supplement (e.g. Foran Equine Chevinal). Once the mare has ceased producing milk and, if needed to maintain optimal condition, Connolly’s RED MILLS Stud Mix or Cubes is an ideal feed for mares that can be gradually reintroduced to the ration.
Until recently, the nutritional needs of the mare during early and mid-pregnancy were often neglected. However, we now know that nutrient requirements increase far earlier than previously thought. Consequently, the diet of the mare during her first and second trimester requires careful consideration in order to ensure that the mare receives optimal energy, protein, vitamins and minerals.
