Breeding dogs using frozen semen requires precise timing to maximize conception rates. Unlike fresh or chilled semen, frozen semen has a much shorter lifespan (12-24 hours once thawed and inseminated), making it critical to inseminate at the exact moment the eggs are mature and ready for fertilization.
The most reliable way to determine this timing is through luteinizing hormone (LH) testing. Understanding the science behind LH testing and learning how to accurately detect the surge will significantly improve success rates when using frozen semen.
Understanding the Canine Reproductive Cycle A female dog goes through four stages in her reproductive cycle: 1. Proestrus – Lasts 7-10 days, marked by vulvar swelling and bloody discharge. Estrogen levels rise, but the bitch is not yet fertile. 2. Estrus – The fertile period, lasting 5-10 days, when LH surges and ovulation occurs. Progesterone begins to rise, and the bitch becomes receptive. 3. Diestrus – The post-ovulation phase, where pregnancy or a false pregnancy occurs. 4. Anestrus – The resting phase before the next cycle.
The most important event for breeders using frozen semen is the LH surge, which signals the beginning of ovulation.
What Is LH and Why Is It Important? Luteinizing hormone (LH) is released by the pituitary gland and triggers ovulation. The LH surge happens suddenly and lasts only 24 hours, making it critical to test daily to catch this brief window.
Once the LH surge occurs:
Since frozen semen survives only 12-24 hours, insemination must occur at the precise moment the eggs are ready to maximize success.
How to Accurately Pinpoint the LH Surge
Why Is LH Testing Crucial for Frozen Semen? Unlike fresh or chilled semen, which can survive in the reproductive tract for several days, frozen semen has a much shorter lifespan (12-24 hours after insemination). So timing must be precise - insemination should happen exactly when the eggs are mature. Miscalculating ovulation can result in fertilization failure and LH testing provides the most accurate prediction of ovulation, ensuring frozen semen is used at the right moment.
LH Testing vs. Progesterone Testing: Which Is Better? While progesterone testing is helpful, it only estimates ovulation based on hormonal trends. LH testing is the only way to pinpoint ovulation precisely.
How to Plan Insemination After LH Surge Detection Once you have detected the LH surge:
Best Methods for Frozen Semen Insemination Since frozen semen has reduced motility and lifespan, direct intrauterine placement is required:
Final Tips for Success