The efficient use of equine cryopreserved semen

Area of Science:

• Reproductive biology
• Veterinary science
• Animal reproduction

Background:

• Efficient utilization of cryopreserved stallion semen is crucial for equine breeding programs.
• Determining the minimum effective insemination dose is key to optimizing fertility outcomes.
• Previous research indicates significant variability in fertility rates with frozen-thawed semen.

Purpose of the Study:

• To investigate the minimum insemination dose of cryopreserved stallion spermatozoa required for optimal fertility.
• To identify factors influencing the success of artificial insemination (AI) with frozen-thawed semen in mares.

Main Methods:

• Analysis of fertility data from studies using cryopreserved stallion semen.
• Evaluation of stallion-specific variations in sperm cryosurvival and in vivo fertility.
• Consideration of critical AI parameters including timing relative to ovulation and insemination site.

Main Results:

• The minimum effective insemination dose for frozen-thawed stallion spermatozoa is highly dependent on the individual stallion.
• Successful pregnancy rates can be achieved with significantly lower numbers of spermatozoa than previously assumed.
• Timing of AI and insemination site are critical factors influencing fertility outcomes with cryopreserved semen.

Conclusions:

• Reducing the insemination dose per insemination can increase the number of doses from a single ejaculate.
• This strategy may enhance the cost-effectiveness of using cryopreserved semen for stallion owners.
• Further research into stallion-specific characteristics and optimal AI protocols is warranted.