Factors influencing the success rate of artificial insemination with frozen semen in the dog.

Abstract

The conception rate and fecundity of 36 bitches artificially inseminated with frozen semen from various sources were investigated: 8 bitches were inseminated with semen frozen at the clinic, and 28 were inseminated with imported frozen semen. The mean progressive post-thaw motility of semen was 60%. Fourteen bitches were inseminated once only and 22 bitches were inseminated twice at 1-2-day intervals. An overall conception rate of 67% (24/36) was obtained with a mean litter size of 6.4. One insemination yielded a slightly lower conception rate than 2 inseminations (64 vs 69%). Among bitches which were inseminated twice, non-pregnant bitches had significantly lower mean plasma progesterone concentrations at the second insemination than did pregnant bitches, and this indicates that the second insemination was performed too early. Correct timing of inseminations is therefore essential to obtain pregnancy with frozen semen.