Stallion Nutrition: Coenzyme Q10 Improves Semen Quality

Stallions must be fed well to fuel spermatogenesis and to ensure breeding success. In addition to good-quality forage and well-fortified concentrates, researchers have identified certain nutritional supplements that improve semen. Researchers recently investigated the possible role of coenzyme Q10 on improving semen quality in stallions.

Coenzyme Q10 is an important cofactor in energy supply for spermatozoa and is responsible, in part, for motility. Two forms of coenzyme Q10 exist, ubiquinone and ubiquinol. Due to its ability to support the renewal of other antioxidants, such as vitamins E and C, coenzyme Q10 slows oxidative damage of lipids in cell membranes. Because of its extensive work in antioxidant mechanisms, tissue and plasma concentrations of coenzyme Q10 can dwindle and negatively affect semen quality.

To determine the effect of coenzyme Q10 on sperm motility and viability after cooling or freezing, researchers recruited seven Andalusian stallions.^* The stallions were fed free-choice mixed grass-alfalfa hay throughout the duration of the study. Stallions were supplemented with one gram of coenzyme Q10 per day for 30 days or they received no supplement. Ejaculates were collected every two weeks over a 60-day period and treated in three ways: (1) cooled for 24 hours; (2) frozen immediately in liquid nitrogen; and (3) cooled for 24 hours and then frozen. Motility and viability of spermatozoa were evaluated in all samples.

Positive effects of coenzyme Q10 supplementation were observed 15 days after supplementation and continued until day 60, which was 30 days after supplementation ended. This coincides with the life cycle of spermatozoa, which is less than 60 days. According to the researchers, “supplementing with coenzyme Q10 resulted in positive effects that were manifest for the life of the spermatozoa, even when coenzyme Q10 was discontinued.”

In two stallions with superior spermatozoa motility, no further improvement was seen in motility with ubiquinol supplementation. Spermatozoa vitality, however, did improve in these stallions.

Of the seven stallions included in the study, five were considered to have suboptimal motility. In these stallions, improvement was noted in all parameters, including total motility, progressive motility, and viability following 24 hours of cooling. The same held true for frozen semen from these stallions.

“Based on the results of this study,” the researchers explained, “there is strong evidence that daily oral supplementation of these stallions with coenzyme Q10 was associated with improved semen quality. These findings are compatible with the results of studies of the effects of daily coenzyme Q10 supplementation on semen quality in men.”

When choosing a coenzyme Q10 supplement, select one from a reputable manufacturer, such as Nano-Q10 from Kentucky Equine Research. According to Peter Huntington, B.V.Sc., M.A.C.V.Sc., director of nutrition for Kentucky Equine Research, “Research has shown that supplementation with Nano-Q10 can rapidly boost levels of coenzyme Q10, and has been fed successfully to a number of stallions since being introduced into the market.”

^*Ruiz, A.J., A. Tibary, R.A. Heaton, I.P. Hargreaves, D.P. Leadon, and W.M. Bayly. 2021. Effects of feeding coenzyme Q10-ubiquinol on plasma coenzyme Q10 concentrations and semen quality in stallions.  Journal of Equine Veterinary Science 96:103303.