Controlled Intravaginal Drug Release (CIDRs) devices are used to release which hormone to synchronize estrus in females?

Controlled Intravaginal Drug Release (CIDRs) devices are specifically designed to release progesterone, a key hormone in the regulation of the estrous cycle in females. Progesterone plays a vital role in preparing the reproductive system for potential pregnancy by maintaining the uterine lining and inhibiting ovulation. By using CIDRs to maintain elevated levels of progesterone, breeders can effectively synchronize estrus in females, facilitating timed breeding and improving reproductive efficiency in livestock operations.

Other hormones listed, such as estrogen, oxytocin, and testosterone, have different roles in reproductive function. Estrogen is primarily involved in the development and regulation of the estrous cycle but is not released through CIDR devices for synchronization purposes. Oxytocin is associated with inducing labor and milk ejection and does not play a direct role in estrus synchronization. Testosterone, while it has roles in male reproductive functions, does not assist in synchronizing female estrus. Therefore, the use of CIDRs to release progesterone is the most effective method for achieving estrus synchronization in female animals.