Effect of Various Combinations of Sugar Supplementation in The Extender on Frozen-Thawed Ram Semen Quality and Fertility

Abstract

Semen cryopreservation alters sperm structure and biochemical properties, and subsequently impairs fertilizing ability. A combination of two different sugar molecules revealed an enhanced beneficial effect on frozen-thawed spermatozoa of various species. However, the report in ram has been scarce. The present study investigated the effect of different combinations of sugar supplementation on post-thawed ram semen qualities in a cryopreservative extender in the presence of a single sugar or a combination of sugars. Data showed that a combination of sucrose and trehalose significantly improved cryopreserved sperm motility, viability, longevity and acrosome integrity. Fertility rates following laparoscopic artificial insemination (LAI) using frozen-thawed semen (n = 35) with the sucrose and trehalose supplementation revealed the same values as those utilizing fresh semen (n = 32) (82.9 v 84.4%, respectively). Our findings suggest that the use of a Tris-Citric extender with the addition of sucrose combined with trehalose is an effective extender for ram semen cryopreservation. The optimization of concentrations and ratios between the combination of sucrose and trehalose supplemented to ram semen freezing extender should be further examined.