Abstract :
The objective of the current study was to evaluate the effects of antioxidant ergothioneine
added to cryopreservation extender on the DNA integrity of Merino ram sperm. Semen
samples from 5 mature Merino rams (1 and 2 years of age) were used in the study. Semen
samples, which were diluted with a Tris-based extender containing ergothioneine at different
concentrations and no antioxidant (control), were cooled to 5 ◦C and frozen in
0.25 ml French straws. Frozen straws were then thawed at 37 ◦C for 20 s in a water bath
for evaluation of sperm DNA damage using the Comet test. The addition of ergothioneine
at concentrations of 1, 2 and 4 mM resulted in lower sperm with damaged DNA (5.4, 4.7
and 3.2%, respectively) than that of control (7.9%), thus reducing the DNA damage (P < 0.01).
Findings of this study showed that the increasing concentrations of ergothioneine in semen
extenders, were of greater benefit to DNA integrity of frozen-thawed ram sperm.
