Equiplanet Gestione Stagione Fredda Cavallo
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Breeding season: stallion and broodmare fertility

Horses breeding season

The broodmare is called a seasonal polyester animal, its calories in fact depend on the season. According to the breed, it reaches sexual maturity between 15 and 24 months and starts cycling at the end of winter, often without ovulation. By the middle of spring, these cycles regularize and then end in autumn. The duration of light hours (photoperiod) influences the hormonal changes and the oestrus of the broodmare.

How to best cope with the breeding season

The breeding season needs management interventions (light exposure, regular exercise, semen control, medical examination, etc.), but especially adjustments in the broodmare and stallion diet from 30 and 60 days before, to help fertility stimulation.

During this period, the stallion must preserve its shape and add to the diet the substances necessary to provide energy both from caloric and supplementation sides: trace elements, vitamins and amino acids to support the effort perpetuated overtime during the season.

In the same way, the broodmare must preserve a body condition score of 5 (Tarleton State Texas University scale) before mating and it is essential to increase the energy concentration of the daily intake one month before the mount up to 20 days after mating.

Complementary feed

Some studies have demonstrated a positive correlation between the diet noble protein content and the production of the hormone that stimulates the maturation of the ovarian follicle and thus responsible for subsequent ovulation. For these reasons, it is recommended to administer a balancer with high protein content (27%) as Mac Breed.

The essential vitamins at this stage

To promote fertility it may be enough to provide vitamin E to the breeders. The requirements for this vitamin is about 1000 IU per day for a horse of 500 kg of weight. The use of this antioxidant is not only useful before conception: researchers at the University of Florida say that an adequate content in the broodmare diet at the end of pregnancy, contributes to the production of good quality colostrum.

Vitamin E

Therefore, complementary feed with a high concentration of Vitamin E, such as Evit 300 (300,000 mg/l) are useful in the breeding season. The international units (IU) refer to the biological activity of vitamin E, while that of synthesis is expressed in mg. A 1 IU of Vitamin E corresponds to 1 mg of synthetic Vitamin E.

In addition to vitamin E, it is important to supply vitamin A and its precursor: beta-carotene. Carotenoids can be found in green plants, so the horse can generally have a good reserve unless its needs increase significantly or if it has no fresh forage or hay available with less than 6 months of age. Beta-carotene is an important antioxidant and enhances the effect of vitamin E. Vitamin A requirement in broodmare is about 30,000 IU per day and it is higher than in athletic horse. Carotenoids are important not only for the antioxidant effect but also because they play an important role in maintaining immunity, which is an essential function for broodmares.

Other integrations

Oral administration of carnitine is useful in stallions with poor semen quality and may improve sperm kinetics and morphological characteristics. In addition, carnitine is important for energy production at the mitochondrial level. Several studies confirm the benefit of its use to improve muscle resistance and promote recovery. For all these reasons it makes a valid support in the stallion, which during the reproductive season, will have to make numerous and protracted physical efforts related to the mounting.

Another important element in the breeder diet are essential fatty acids, such as omega 3. The horse takes Omega 3 from forages, especially from fresh ones. The cereal-based diet, which mainly contains Omega 6, can unbalance the 3-6 ratio. For all these reasons, it is important supply Omega 3 with the daily ration to keep balanced the ratio and even more to satisfy the needs in particular phases, such as the reproductive one.

Several studies have been conducted on the correlation between Omega 3 diet supplement and fertility. It has been shown that, in the fresh and in the frozen one, there are encouraging results regarding the motility and the quality of the semen.

While for the broodmares, some studies on Omega 3 have proved their usefulness because they are essential for the growth and development of the foetus. Other research has shown that lactating broodmares, fed with fibre and fats/oils, produce a milk whose composition improves the health of the foal.

Omega 3 Omega 6

A product that helps to promote fertility because it contains all the above-mentioned components is surely Omega Energy. This complementary feed is formulated with raw materials and additives that provide Omega 3, Vitamin A, Vitamin E, Beta-carotene, Selenium, Carnitine, which is a valid support for breeders and stallions during the breeding season.

The correct management and a balanced diet of broodmares and stallions, allow maximizing the reproductive efficiency and limiting the problems related to reduced fertility and poor processability of the semen.


  • Effect of a dietary antioxidant supplementation on semen quality in pony stallions, Deichsel K, Palm F, 2008
  • Effect of L-carnitine administration on the seminal characteristics of oligoasthenospermic stallions, Stradaioli G, Sylla L, 2004
  • Effect of dietary supplementation with long-chain n-3 fatty acids during late gestation and early lactation on mare and foal plasma fatty acid composition, milk fatty acid composition, and mare reproductive variables. Kouba JM, 2019
  • Effects of oral supplementation with β-carotene on concentrations of β-carotene, vitamin A and α-tocopherol in plasma, colostrum and milk of mares and plasma of their foals and on fertility in mares. Kuhl J, 2011
  • Introduction to horse nutrition, Zoe Davies first edition