Best Time of Insemination in the Mare

Best time of insemination in the mare is:

Correct Answer: Every 2nd day during estrus

In mares, heat lasts for about 6 days and ovulation occurs 24–48 hours before the end of estrus. The recommended strategy is to inseminate every 2nd day during the entire estrus period to ensure spermatozoa are present at the time of ovulation.

Why Every 2nd Day?

• Mares show a prolonged estrus (6 days), making it difficult to pinpoint exact ovulation timing.
• Fertile lifespan of sperm in mares is 4–6 days (much longer than other species).
• Inseminating every 48 hours ensures continuous coverage throughout the fertile window.

Additional Methods in Mares

• Rectal palpation and ultrasonography can help detect the pre-ovulatory follicle (≥35 mm) to time insemination more precisely.
• hCG injection can be used to induce ovulation and allow a single, timed insemination.