Practicalities of insemination of mares with deep-frozen semen.

This study discusses the detailed processes and outcomes of inseminating mares with frozen sperm, including success rates of horse breeds, mare receptiveness, variability among technicians, and overall pregnancy and foaling rates.

Stallion Participation and Sperm Quality

• The research involved examining the sperm quality of 341 stallions, which are male horses.
• 61% of warm-blooded stallions and 47% of cold-blooded stallions met the preset criteria used for occasional insemination. Warm-blooded and cold-blooded are terms referring to horse breeds and have nothing to do with their actual body temperature.
• Of these stallions, between 51% to 71% of ejaculates were deemed acceptably viable for insemination purposes.

Mare Insemination and Pregnancy Rates

• A total of 959 mares, or female horses, were inseminated over an average of 1.36 oestrous cycles. An oestrous cycle is the reproductive cycle in females.
• During each of these cycles, an average of 2.2 insemination doses were required for a mare.
• The overall pregnancy rate observed during the research was 56% while the foaling rate or successful birth rate was 48%.

Insemination Technicians and Variability

• 41 trained cattle insemination technicians were involved in the process, specifically trained in mare insemination for this research.
• There were noted differences in the pregnancy rates of mares depending on which technicians performed the insemination, with rates varying from 0% to 79%. This suggests that the skill and technique of the inseminator can significantly influence the success rate.
• Differences were also observed in the fertility rates among individual stallions, ranging from 29% to 62%. This variation indicates that factors inherent in the specific stallions also play a key role in the success of the insemination process.