Cryopreservation of ram sperm from autohtonous breeds as a method f0r preserving biodiversity

Abstract

In the last few decades biodiversity of domestic animals has been declined. The importance of preserving indigenous breeds is reflected in the fact that they contain the original genetic code, are adaptable to adverse conditions and more resistant to disease. In this study we have investigated the possibility of cryopreservation of ram sperm as a method for preserving biodiversity. Cryopreservation of the Wallachian sheep gametes would allow easier exchange of genetic material between geographically distant locations and, thus, expand the genetic diversity of otherwise small and distant locations. The experiment was performed on rams of Wallachian sheep breed. Six semen samples from two rams were collected by electroejaculation. After collection and 60 or 120 min of incubation at 37 oC the sperm was analysed for motility by a computer-assisted sperm analyser. Collected sperm was diluted and frozen in straws using a rapid freezing method. The straws were thawed after one month. Results of this study showed that freezing influenced total and progressive motility compared to fresh sperm (P = 0.000). Comparing progressive motility immediately after thawing, and 60 or 120 min after thawing we found statistically significant differences between both rams (Ram 1, P = 0.0359; Ram 2, P = 0.0361). In this experiment inter-male variability was not confirmed. For further analysis higher number of animals and other breeds need to be tested.