Sources of spermatozoa loss during collection and artificial insemination of horses

During artificial insemination of horses, it is important to accurately estimate the number of spermatozoa in each insemination dose. However, little research exists regarding sources of spermatozoa loss during collection and artificial insemination. Therefore, spermatozoal losses were quantified in the dismount loss (187.6 × 106 ± 62.5 × 106 spermatozoa), gel fraction (179.8 × 106 ± 61.7 × 106 spermatozoa), and the collection receptacle (136.1 × 106 ± 26.9 × 106 spermatozoa). Spermatozoal losses were examined in the centrifuge tube (25.8 × 106 ± 2.1 × 106 spermatozoa), AI pipette during the air removal (90.9 × 106 ± 8.5 × 106 spermatozoa), and spermatozoa remaining in the AI pipette after insemination (342.9 × 106 ± 21.4 × 106 spermatozoa). The average cumulative loss was 14.2 ± 2.9% of the total spermatozoa ejaculated with approximately half of the loss due to the process of semen collection and half due to the process of artificial insemination. Spermatozoa retained in the AI pipette, after insemination with extended semen, represented the greatest source of loss.