Nutritional requirements of broodmares change throughout the stages of reproduction and it is important to adopt a flexible feeding programme to ensure nutrient requirements are being met at each phase.
Reproduction can be separated into early pregnancy, which is first and second trimester or 0 to 7 months gestation, late pregnancy, which is third trimester or 7 months gestation through to foaling, and lactation, which generally lasts for 5 to 6 months post-foaling.
In early pregnancy, the mare’s energy and nutritional requirements are similar to maintenance. While it is tempting for owners to increase feed when they discover the mare is pregnant, the “eating for two” rule does not apply unless the mare has a foal at foot and is lactating as well. Increasing feed at this time can often lead to weight gain and associated problems, especially if the mare is generally a “good doer”. At this stage of pregnancy, 1.5 percent body weight in forage and a balancer pellet such as NRM Mare Balancer is normally sufficient.
Energy requirements in third trimester are about 15 percent greater than in early pregnancy and protein, amino acid and mineral requirements also increase significantly. Foetal nutrient requirements exceed the mare’s maintenance requirements at this time and the mare’s diet must be adjusted accordingly. The most important nutrients for the third trimester are the trace minerals zinc, manganese, iron, selenium and copper, as these are found at low levels in the mare’s milk. Therefore, the foal needs to store these in the liver in the last 3 months of pregnancy to compensate for the low levels they will be receiving once they are born. Regarding diet, 1.5 percent body weight in forage and a balancer pellet such as NRM Mare Balancer, or a well-fortified feed such as NRM Evolve or McMillan Broodmare is ideal. Additional energy can be supplied in the form of grain or the high fat stabilised rice bran KER Equi-Jewel, if needed for weight maintenance.
When the foal is born, the demands of lactation lead to large increases in requirements for energy, protein, calcium and phosphorus. Mares produce milk at a rate of 3 percent of their body weight daily and weight loss will occur if energy needs are not met. It is important not to underfeed in lactation and always provide adequate calories to prevent weight loss. As well as increasing energy sources in the form of concentrates, lucerne hay provides additional energy than grass hay types, as well as a source of protein and calcium. NRM Evolve or McMillan Broodmare are ideal for lactating mares and additional grain or KER Equi-Jewel can also be included in the diet to increase calories if required.
The overall goal of broodmare feeding should be to provide adequate energy to maintain optimum body condition while ensuring protein, vitamin and mineral requirements are appropriate for her stage in the reproductive cycle.
For assistance with feeding plans for mares for conception through to pregnancy and lactation, consult with an experienced equine nutrition advisor.
Article supplied by Luisa Wood, Equine Nutrition Technical Advisor.