Skimmed goat milk heated at 92℃ for 10 minutes was used as a basal extender for bull semen. The extenders for liquid semen were prepared by adding simultaneously at various ratio of 5% dextrose solution and egg yolk to skimmed goat milk. After bull seven was diluted with the extenders at the rate of 20 million spermatozoa per ㎖ of the extenders. The extenders were stored at 5℃ and the survival rates of spermatozoa were examined at 4 and 24 hours, and 3, 5 and 7 days after dilution.
The extenders for frozen semen were prepared by adding various ratlo of glycerol to skimmed goat milk containing 20 parts of 5% dextrose solution and 3 parts of egg folk to 77 parts of skimmed goat milk. After bull semen was diluted with the extenders at the rate of 40 million spermatozoa per ㎖ of the extenders, the extenders were frozen in liquid nitrogen tank. The frozen extenders were thawed at 40℃ for 2 minutes, and the revival rates of the spermatozoa in the extenders were examined. These thawed extenders were stored at 5℃ and the survival rates of the spermatozoa were examined at 10 minutes and 24 hours and 3 and 5 days after thawing.
The results obtained were as follows:
1. Among the extenders stored at 5℃, the survival rate of the sperm was the highest in the extender including 20 parts of 5% dextrose solution and 3 parts of egg yolk to 77 parts of skimmed goat milk, and the survival rate was significantly higher that of the spermatozoa in egg folk-2.9% sodium citrate (1 : 4) extender. (P<0.05)
2.Among the extenders frozen in liquid nitrogen tank, the revival rate of the spermatozoa was the highest in the extender containing 7㎖ of glycerol per 100㎖ of the extender with consisted of 77 parts of skimmed goat milk, 20hparts of 5% dextrose solution and 3 parts of egg yolk, and the revival rate was significantly higher than that of the spermatozoa in egg york-2.9% sodium citrate (1 : 4) extender containing 8㎖ of glycerol per 100㎖ of the extender (p<0.01).
3. Among the extenders stored at 5℃ after thawing, the survival rate of the spermatozoa was the highest in the extender containing 7㎖ of glycerol per 100㎖ of extender which consisted of 77 parts of skimmed goat milk, 20 parts of 5% dextrose solution and 3 parts of egg yolk, and the survival rate was significantly higher than that of the spermatozoa in egg york -2.9% sodium citrate (1 : 4) extender containing 8㎖ of glycerol per 100㎖ of the extender (p<0.01).
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