Onset of estrus and preovulatory LH surge and ovulatory efficiency in sheep after short-term treatments with progestagen-sponges and progesterone-CIDRs

Abstract

The present study supports that short-term (7-days) protocols based on progestagen-impregnated sponges and progesterone-loaded CIDRs are equally effective to induce ovulatory response in sheep. There were no significant differences in the onset of estrus behavior (32.0±6.0 and 33.8±4.0h after device withdrawal for sponges and CIDRs, respectively; p > .05) and preovulatory LH discharge (5.1 ± 2.1 and 5.8 ± 3.3h after onset of estrus behavior for sponges and CIDRs, respectively; p > .05). These features are similar to previously described for classical long-term (12-14 days) treatments. Hence, short-term CIDR-based protocols may be implemented using the same time-intervals for insemination than sponge-based and long-term protocols.