by Dr. Clair Thunes PhD, Nutritionist for EnviroEquine & PET ~

Breeding season may feel like a long time away but when it comes to stallion fertility action needs to be taken now for those stallions with a less than stellar record. Spermatogenesis, or the production and development of mature sperm takes almost two months in the horse. Therefore, any action to ensure quality sperm in the new year needs to be taken now.

The outermost layer of the sperm cell is covered with a layer called the plasma membrane. This membrane is made up of fatty acids, in particular polyunsaturated fatty acids or PUFA’s. It is thought that with a more fluid plasma membrane sperm may be better able to withstand the processes of freezing and thawing. Research has shown that when stallions are supplemented with the type of PUFA’s found in EnviroEquine’s OmegaBalance, the motility, vigor and osmotic tolerance in freeze-thawed sperm was higher than in those stallions not provided the supplemental PUFA.

Further research has found similar results and the improvement is particularly notable in stallions with poor or moderate sperm quality. The stallions in the study referred to above were fed a hay-based diet as is the case for many stallions. While fresh pasture can be a rich source of PUFAs, these fats are unstable when heated and so are lost during the hay making process. This means that horses on hay-based diets benefit greatly from supplemental sources of omega fatty acids. The Camelina oil in OmegaBalance is a rich source PUFA as omega fatty acids in particular omega-3 fatty acid.

Another key nutrient that is abundant in fresh pasture but lacking in hay-based diets is vitamin E. This vital antioxidant is also heat sensitive and many equine diets are lacking. Add to this the fact that large variation in how individual horses utilize dietary vitamin E and some horses who on paper are being fed adequate vitamin E will in fact be deficient.

Supplements fed to stallions containing omega-3 fatty acids and vitamin E have been shown to increase total sperm motility, acrosomal membrane integrity as well as speed in fresh and cooled semen. However, there was no difference in sperm volume, appearance, or concentration between those stallions supplemented and those given the placebo. In addition to OmegaBalance, EnviroEquine provides vitamin E in the form of Emcelle tocopherol. This water micellized natural vitamin E is the most bioavailable form of vitamin E available on the market today and proven to raise serum vitamin E levels in a matter of hours. Stallions, like all performance horses, should have their vitamin E levels checked by a veterinarian on a regular basis to determine whether supplementation is necessary.

With breeding season right around the corner, now is the time to assess sperm quality and implement dietary changes that may improve semen quality and increase your stallion’s success in the breeding shed in 2020.