Indexed on: 10 Oct '16Published on: 09 Sep '16Published in: Journal of Equine Veterinary Science
Stallion semen cryopreservation is often associated with poor post-thaw sperm quality. Sugars act as non-permeating cryoprotectants. The aim of the present study was to evaluate the cryoprotective effect of trehalose on stallion sperm quality and field fertility rates subjected to cooling and freeze–thaw process. Semen samples were collected from 6 Arabian stallions, divided into five different treatments in a final concentration of 100 x 106 sperm/mL by using INRA-82 extender containing 0, 25, 50, 100 and 200 mM of trehalose then subjected to both cold-storage and cryopreservation. Sperm motility, acrosome, plasmatic membrane and DNA integrity were analyzed and 57 mares were used to evaluate the field fertility of chilled and frozen-thawed semen. Results showed that, the extender containing 100 mM trehalose only increased the functional acrosomal, plasma membrane and DNA integrities. The inclusion of 50 mM trehalose in semen extender resulted in significantly (P< 0.05) increased post-thaw total motility compared to the control group and chilled semen achieved higher pregnancy rates compared to the frozen thawed one. Pregnancy rate of mares inseminated with frozen-thawed semen (P ˂ 0.05; 46.15% vs. 36.36%, respectively) was lower than those inseminated with chilled semen (76.47% vs. 68.75%, respectively) but higher than control. In conclusion, addition of 50 mM trehalose yielded the highest quality stallion semen after cooling and post-thawing in terms of motility, integrities of acrosome, membrane and DNA as well as improved field fertility.