Bovine Semen Frozen in Liquid Nitrogen Vapor

Laboratory studies employing the split-ejaculate technique from eight mature bulls were used to evaluate the effects of per cent glycerol levels of 6, 7, 9, and 11 and equilibration time of 6, 8, 12, and 18 h r frozen in liquid nitrogen vapor (LWV) .Highly significant differences ( P < 0.01) between equilibration time (hours) and per cent glycerol levels were found.A further breakdown of the analysis showed that 7% glycerol a t 12 h r equilibration was superior ( P < 0.05) to the remaining treatments.I n the fertility study, split ejaculates from seven mature bulls (two Jersey, three Holstein, one Guernsey, and one Angus) v7ere used to study the effects of freezing semen in LNV and dry ice and alcohol.The mean prefreezing and post-thawing motility values ~vere essentially the same for both treatments.Also, differences between treatments after 3 wk storage were not significantly different (P > 0.05).Fertility based on GO-to 90-day nonreturns for 824 first services was 76.1% for the semen frozen in LNV, as compared to 75.5% for 853 first services for