Effects of Feeding Coenzyme Q10-Ubiquinol on Plasma Coenzyme Q10 Concentrations and Semen Quality in Stallions

Abstract Although coenzyme Q10 (CoQ10) serves as an antioxidant and energy source for spermatozoa when added to stallion semen prior to cooling or freezing, the effects of feeding CoQ10 on semen quality have not been studied. We assessed the effects of daily oral ingestion of CoQ10-ubiquinol by stallions on their plasma CoQ10 concentrations and semen quality. Seven mature Andalusian stallions ate 1g ubiquinol/day for 4 weeks followed by a 4-week wash-out period. Four horses initially completed an additional 4-week control period without ubiquinol. Blood was sampled weekly for determination of plasma CoQ10 concentrations. Ejaculates were collected every two weeks and assessed for total motility (TM), progressive motility (PM) and viability (V) after cooling for 24h (T1), immediate cryopreservation (T2), and cryopreservation following 24h cooling (T3). Ingesting ubiquinol resulted in an increase in plasma CoQ10 concentration (p Feeding 1g CoQ10-ubiquinol for 4 weeks to breeding stallions improved semen quality after cooling and freezing in 5 of 7 stallions. This could be important for improving reproductive efficiency in stallions.