Computerized and subjective assessments of post-thaw motility of semen from Finnish Ayrshire AI bulls in relation to non-return rates.

A semen analyser (Lazymot), was used to evaluate post-thaw motilities in 296 batches of semen from 74 Ayrshire bulls used for artificial insemination (AI). Motility was also assessed subjectively. A significant correlation was observed between assessments of motility using the Lazymot analyser and the subjective assessments. There was no correlation between post-thaw motility assessments and non-return rates in relation to the batches examined, which met Finnish criteria for use in AI. This suggests that criteria for post-thaw semen motility should not be increased beyond the present requirement for 40% motile spermatozoa.