개의 인공수정에 사용할 정자의 보존방법을 확립하기 위하여, 동결속도와 응해 온도를 설정하여 적절한 동결방법을 정립하고자 본 실험을 실시하여 다음과 같은 결과를 얻었다. 동결의 방법에 있어서는 액체질소의 표면으로부터 17 cm 높이에서 동결하는 -3$^{circ}C$/min의 동결속도로 실시하여 37$^{circ}C$에서 2분간 응해하는 방법이 가장 좋은 결과를 보였다. 생존성과 운동성에 있어서의 차이는 없지만 첨체의 intact한 비율은 약간 낮은 결과를 보였으며, 이의 보완을 위해, 액체질소 표면으로부터 10cm와 17cm의 높이를 세분화하여 동결속도를 설정한 후보다 나은 정액동결방범을 찾는다면 동결정액을 이용한 인공수정의 수태율은 더욱 향상될 수 있을 것으로 사료된다.
The aim of this study was to identify the method on extended canine semen exposed to freezing as assessed by motility, survival and acrosomal changes following different freezing ramp rates. Five ejaculates collected by digital manipulation twice weekly from three dogs (Shih-Tzu) were added Tris-Egg Yolk (TE) buffer and divided into 4 aliquots according to formulation of our laboratory. After cooling to 4$^{circ}C$ by ramp rate of 0.6$^{circ}C$/min, the samples frozen by ramp rates of 1.6$^{circ}C$/min to -$25^{circ}C$, 3$^{circ}C$/min to -35$^{circ}C$, 8.9$^{circ}C$/min to -7$0^{circ}C$ and 19$^{circ}C$/min to -11$0^{circ}C$, respectively, and then stored in L$N_2$for 2days. Each sample was evaluated on their motility, survivability and acrosome integrity at different thawing temperature. The ramp rate of 3$^{circ}C$/min to -35$^{circ}C$/h for freezing and thawing temperature of 37$^{circ}C$ obtained the highest results to improve survivability, motile spermatozoa and intact acrosome appearance than other onditions. In conclusion, we may suggest freezing semen for canine artificial insemination is more efficient with freezing at a ramp rate of -3$^{circ}C$/min to -35$^{circ}C$ and thawing with a water bath adjusted to 37$^{circ}C$.
