Ovulation timing - Concepts and controversies

摘要

Left to their own behavior and responding to nature's signals, the majority of dogs will breed at a time appropriate to result in conception. Nevertheless, improper timing is the most common reason that breedings fail.(15,32) This phenomenon is a result of two properties inherent in canine reproduction. The first is that the true fertile period of the bitch is short, since mature, fertilizable ova are only viable for a period of 48-72 hours.(4, 30) In addition, sperm longevity in the female reproductive tract is often extended (6-11 days),(9, 10, 18) allowing breedings that occur considerably before the fertile period to produce pregnancy. However, if sperm longevity is compromised even slightly, or if the number of breedings is Limited, matings timed by nature's signals alone may not result in live sperm present during this critical time. As a result, identification of the true fertile period will maximize the probability of a successful breeding.