SAEVA Proceedings 2018 4. Proceedings | Page 155

SAEVA Congress 2018 Proceedings | 12-15 February 2018 | ATKV Goudini Spa found in their CoQ10 can vary considerably. As CoQ10 is absorbed from the g-i tract as ubiquinol, it makes great sense to administer the supplement in that form as its bioavailability is greatly enhanced. Stallion Fertility Oxidative stress has a clearly recognized role in male infertility, and several studies have been focused on the role of antioxidant therapy on semen quality and reproductive outcome in a variety of species, but not the horse. Spermatozoa physiologically produce ROS that are involved in protein tyrosine phosphorylation during sperm capacitation; ie, this process is essential to normal sperm function. ROS come not only from spermatozoal mitochondria, but also from neutrophils and macrophages. High ROS levels can exceed the sperm antioxidant defenses and have a strong negative effect on semen quality. This oxidative stress is now recognized as a major contributing factor to male infertility. Oxidative sperm damage includes DNA fragmentation, altered mobility and reduced capacity of the spermatic membrane to fuse with oocytes. The susceptibility of spermatozoa to oxidative stress damage is due to (i) large amounts of polyunsaturated fatty acids in the phospholipid membrane; (ii) limited anti-oxidizing capacities of the cell; and (iii) the great ability of spermatozoa to generate ROS, although indispensable, at physiological levels, for adequate sperm functionality. Antioxidants have been successfully used to treat male infertility and to improve sperm motility and membrane integrity stability in men, bulls, rams, goats, boars and dogs. Although the importance of CoQ10 in health and disease and its critical role in cellular bioenergetics have been well established in various species, there is a total lack of information on the effects of dietary supplementation of CoQ10 on stallion semen quality. However, given the safety of the substance and the positive effects of supplementation on male fertility in other species, there is good reason to believe that there will be similar beneficial effect on the fertility of stallions, especially those with heavy work loads. Another significant source of sperm oxidative stress arises from sperm handling and cryopreservation procedures during assisted reproduction. The supplementation of bovine sperm media with CoQ10, zinc and D-aspartate improved the developmental competence of embryos produced in vitro and their ability to implant and give rise to healthy calves. The most commonly used technique in the global equine industry for assisted reproduction is artificial insemination with fresh, cooled, or frozen semen. High-quality semen is dependent on several major factors, including proper management, good health care, and sufficient nutrients to meet the needs of reproductive male horses. 150