Motility and fertility of bovine semen stored at -79° C and -196°C

Abstract

The percentage of motile spermatozoa in bovine semen frozen in ampoules and stored for 120 days either at -79° G in solid carbon dioxide-alcohol or at -196° C in liquid nitrogen was compared. The percentage motile spermatozoa was higher (P < 0.01) after 14 days' storage at -196° G than at -79° C. This difference was still apparent after 120 days' storage (P < 0.01). The transfer of semen from storage in solid carbon dioxide-alcohol to liquid nitrogen produced no change in the percentage of motile spermatozoa. However, when semen was transferred from liquid nitrogen storage to solid carbon dioxide-alcohol there was a decline in motility similar to that found at primary storage in solid carbon dioxide-alcohol. Split batches of semen stored for 90 days in solid carbon dioxide-alcohol and liquid nitrogen were used for the insemination of cows. The solid carbon dioxide-alcohol stored semen was transferred to liquid nitrogen for field storage. The 60- to 90-day N.R. rates were 70.9% for semen stored in solid carbon dioxide-alcohol and 73.5% for semen stored in liquid nitrogen.-A.S.