Phinehas Adams

Equine Nutrition for Breeding and Growth

From the exciting news of conception to raising a horse through the stages of development from foal to maturity, breeding can be an extremely rewarding part of horse ownership. The specific nutritional needs of the broodmare and growing horse are constantly changing and it is important to alter feeding programmes according to the different stages.


Nutritional requirements of broodmares change throughout the stages of reproduction, and it is adopting a flexible feeding programme to ensure nutrient requirements are being met at each phase is essential. Reproduction can be separated into early pregnancy, which is the first and second trimester or 0 to 7 months gestation, late pregnancy, which is the 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% body weight in forage and a balancer pellet such as NRM Mare Balancer or NRM Progress is normally sufficient.

Energy requirements in the third trimester are about 15% greater than in early pregnancy, and protein, amino acid and mineral requirements also increase significantly. Foetal nutrient requirements exceed 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 three months of pregnancy to compensate for the low levels they will be receiving once they are born. Regarding diet, 1.5% body weight in forage and a balancer pellet such as NRM Progress, or a well-fortified feed such as NRM Evolve, McMillan Broodmare or McMillan Rapid Gain 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 phosphorous. Mares produce milk at a rate of 3% 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, McMillan Broodmare or McMillan Rapid Gain are ideal for lactating mares, and additional grain or Equi-Jewel can also be included in the diet to increase calories if required.

Once the foal is old enough, weaning is often the time when mares will gain weight as lactation gradually ceases and energy is no longer required for milk production. Mare dietary alterations should therefore occur according to body condition and most mares will require less hard feed than when they had a foal at foot. Mares who gain weight easily can be transitioned onto a balancer pellet such as NRM Mare Balancer to ensure nutrients are still supplied in the diet without adding calories and contributing to weight gain.

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.


Once born, foals will obtain all they require nutritionally from the mare’s milk until approximately 3 months of age. At this time the nutritional value and energy of the milk begin to decrease and the foal will require supplementary feed to meet their individual requirements. At this age, the foal will also be learning to consume grass and other forages by copying the mare and other horses.

Sharing the mare’s feed initially is a great way for the foal to be introduced to concentrates if the mare allows it! Mares will often be reasonably obliging when the foal is young however they may start to protest as the foal gets bigger and more aggressive. At this time it is recommended to provide the foal with its own meal to ensure individual nutrient requirements are met, and to give the mare a break from her persistent offspring! High-quality breeding feeds such as NRM Progress, Evolve or McMillan Broodmare are ideal first-time feeds for foals and mean the transition from the mare’s feed bin to their own is easy and convenient.


Eventually, the time will come to separate the foal from the dam, and the later summer months of February and March are common, particularly for commercial equine breeders. Correct nutrition is essential for what can be a stressful time. Planning is required and strategies for weaning will differ according to facilities available and procedures that have been adopted to minimise stress and make the process as smooth as possible. The herding nature of the horse means they are required to have constant company and while larger establishments will often wean foals so they are paddocked together, owners with single foals will most likely require another equine companion for them.

In most cases, broodmares are less affected by weaning and some will be more than ready to be separated from their young energetic offspring. Ensuring the foal is accustomed to the hard feed the mare was receiving throughout lactation is an important factor in decreasing the stress associated with weaning. A familiar feed helps to minimise complications associated with introducing a new feed at the same time as the stress of separation.

The pressure of weaning can increase the risk of digestive conditions such as gastric ulcers and it is important to monitor weanlings for associated signs. These include inappetence, behavioural changes and weight loss however conditions can also be asymptomatic. Seeking veterinary advice if digestive conditions are suspected is advised.

Most foals are weaned from at least five to six months of age and by this stage, they are independent and able to consume any forage or hard feed required. The time of growth between six and twelve months is crucial for skeletal development as the risk of developmental orthopaedic diseases is high. Research has shown that to minimise the risk of conditions such as osteochondritis, physitis and wobblers developing, the most important considerations are to achieve steady growth, and to provide a low glycaemic diet that is balanced for all essential vitamins and trace minerals. Suitable feeds in this case include NRM Evolve or McMillan Rapid Gain, as well as NRM Progress for weanlings that do not require significant amounts of feed to maintain optimum condition.

Steady growth in weanlings is achieved through monitoring conditions carefully and avoiding any rapid changes through altering energy intake accordingly. While many people, particularly experienced stud managers, have a highly experienced eye and can spot changes in body condition quickly enough, weighing and measuring weanlings gives much more accurate readings, as well as the ability to compare values as they grow and look for any significant changes. Body condition is best-kept light to avoid overloading growth plates during this crucial time, and it is often recommended to be able to faintly see the outline of the last two ribs. Once the horse reaches twelve months and is past the most vulnerable stages of growth, the condition can be increased carefully to an optimum condition for the intended purpose.


Although twelve months and older is arguably past the most vulnerable time for skeletal development, steady growth is still important until the horse reaches full maturity. The amount of hard feed required is unlikely to change significantly from when the horse was a weanling unless the horse is being prepared for sales and the workload is increasing. Maintaining the horse on a breeding feed until maturity is recommended, and feeds such as NRM Evolve, Progress and McMillan Rapid Gain is ideal.

Providing the best diet for the growing horse requires adequate forage and the selection of a breeding feed that has a low glycaemic index to avoid peaks in blood glucose and is balanced for all nutrients essential for optimum growth and development.

For assistance with feeding plans for growing horses and broodmares at any stage of pregnancy, consult with an experienced equine nutritionist.

Article supplied by Luisa Wood, Equine Nutritionist.