There is no doubt that nutrition plays a critical role during the breeding season with broodmares and stallions requiring the correct amounts of energy, protein, vitamins and minerals for their own maintenance, to optimise fertility and for the development of the fetus and foal. Ensuring these requirements are met does not need to be complicated. In this article we hope to give you some tips to ensure optimal nutrition throughout the breeding season.
Monitor Body Condition
Body condition scoring evaluates the level of fat cover on a horse and is indicative of energy intake and storage of extra energy intake as fat. This makes it an effective way to evaluate whether broodmares or stallions are receiving an adequate, excessive or an inadequate energy intake. It is recommended that both broodmares and stallions are maintained at a body condition score (BCS) of 5-6 (on the Henneke scale of 1-9), which is a moderate to moderate-fleshy cover of fat. This is the optimal weight to help maximise fertility and provides a buffer of stored energy that the horse can utilise as they undergo changes throughout the season. It is important to continue to monitor BCS so that the appropriate feed rations can be selected, and necessary adjustments made.
Understand energy and protein requirements
The energy and protein requirements of stallions is going to vary between individual stallions, based on their breeding frequency, level of exercise, housing, and temperament. So, it is important to evaluate this on an individual basis. However, in general stallions have similar requirements to horses in light – moderate work.
Nutrient intake of pregnant mares needs to meet their own maintenance requirements and the nutrient needs for the synthesis and maintenance of the products of conception. In early gestation, energy and protein intake does not need to be much higher than maintenance as most fetal growth occurs during the 3rd trimester of gestation. The energy and protein requirements to fuel this growth begin to increase above maintenance in the 5th month of gestation and continue to increase throughout the rest of gestation.
Early lactation is the most nutritionally demanding period, and it is important that mares energy and protein intake is increased to allow them to meet the needs of lactation whilst maintaining their own body stores. If energy and protein requirements are not met, mares will generally mobilise their own body stores to produce milk, which can result in weight and muscle loss. However, their bodies will only do this to a certain point and if requirements are not met this will begin to reflect in the foal’s growth and development; with studies showing that foals of mares fed a low protein diet were smaller at 90 days than the foals of mares fed a high protein diet during lactation. Ensuring an adequate BCS and protein intake during lactation is also of higher importance if the mare is being rebred within 30 days post-partum, as mares with a BCS of less than 5 have a reduced reproductive efficiency.
The additional energy and protein supplied in the diet is very much dependent on pasture quality and quantity. As with any other horse, forage should form the basis of breeding horses’ diets. Stallions and pregnant mares on high quality, abundant pasture may have majority of their energy and protein requirements met by pasture alone and only require a vitamin and mineral supplement. While those on lower quality pasture will likely need supplementation with a higher quality hay as well as additional supplementary feed to ensure requirements are met. For mares in early lactation pasture alone is rarely enough and a daily supplementary feed is often necessary to meet requirements. It is important to continue to monitor pasture quality and quantity alongside body condition scores to ensure adequate intake.
Protein quality within supplementary feeds is also an important consideration. High quality protein sources – proteins high in digestible essential amino acids – such as soybean are essential for muscle maintenance and repair in stallions, for the adequate growth and development of the fetus and for milk production and composition in the lactating mare which corresponds with healthy foal growth and development.
You can download our protein quality fact sheet here:
Ensure adequate vitamin and mineral intake
Meeting the vitamin and mineral requirements of breeding stallions is important for general health but also helps to support fertility and joint health. Studies have suggested that deficiencies of Vitamin C, Zinc, Selenium and B Vitamins in a stallion’s diet affect sperm production and/or sperm quality. A diet balanced with vitamins and minerals also helps to support joint and bone health which are placed under added strain during breeding season.
Ensuring a balanced diet in breeding mares is essential to ensure adequate growth and development of her foal. For example, foals born to mares deficient in copper have a significantly increased risk of articular cartilage scores and worse physitis scores compared to foals born to mares fed sufficient copper during pregnancy. Studies have also shown that foals born to mares deficient in iodine may be weak with a poor suckle response and can have flexural limb deformities. Maintenance of adequate vitamin and mineral intake is also important if mares are being re-bred within 30 days post-partum as studies have suggested that vitamin and mineral deficiencies may affect reproductive rates.
Pasture and hay alone do not meet the vitamin and mineral requirements of horses at maintenance, let alone a breeding stallion or pregnant mare. Therefore, supplementation with a vitamin and mineral pellet or fortified feed is necessary for these requirements to be met. Mineral intake from a trace mineralised salt block or mineral block is likely to be erratic and is unlikely to meet requirements, hence a ration balancer pellet is recommended. The added benefit of a ration balancer is ensuring that essential amino acid requirements are met if protein quality of the pasture is lacking.
When selecting a feed, it is important to select one that has feeding rates similar to what your mare or stallion requires or to make use of a combination of a full feed with a balancer pellet (found in the ‘Keep it Balanced section’ on our bags and website) to ensure adequate vitamin and mineral intake.
Below are some balanced diet recommendations for mares and stallions
Mares in early gestation and stallions with lower activity or needing to lose weight:
Mares in late gestation and stallions in higher activity:
Mares in early lactation and stallions with high activity that struggle to hold weight:
Pasture quality and quantity may also range throughout the season, any of the Pryde’s full feed or concentrate range if fed under the recommended feeding rate can be fed in conjunction with a balancer pellet to maintain appropriate body condition score while ensuring adequate vitamin and mineral intake. Here is an example for a 500kg pregnant mare:
If you would like to read more specific information about feeding stallions and broodmares checkout the Pryde’s Information Hub by clicking here.
The above diets are general recommendations, it is important to consider each individual horse, their body condition, pasture access and environment to determine nutritional requirements. For a complete diet analysis and recommendations for your stallions or mares please use our free feed selector or get in contact.
Written by Bethanie Clark BAnVetBioSc (Hons I)
Lawrence, L. M. (2013). Feeding stallions and broodmares. Equine applied and clinical nutrition: health, welfare and performance. R. J. Geor, Harris, P.A. & Coenen, M. Edinburgh, Saunders/Elsevier: 231-242.
National Research Council. (2001). Nutrient Requirements of Horses. Washington, D.C., The National Academies Press.