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Efficacy of OvSynch Alone or in Combination with Intravaginal Progesterone
by Teresa L. Steckler, Theodore F. Lock, Gene C. McCoy, and Darrel J. Kesler

Take Home Messages

  • OvSynch effectively prepares lactating dairy cows for breeding via AI. Because cows are bred at a predetermined time rather than at estrus, OvSynch increases the number of cows that conceive over a given period of time and obviates the need for estrus detection.
  • Administration of a intravaginal progesterone insert improved efficacy of OvSynch.


Although various procedures to synchronize estrus and ovulation, prostaglandin F2" (PGF2") is the only compound approved for use in dairy cattle. Gonadotropin releasing hormone (GnRH) is approved for the treatment of cystic ovarian disease. Recently, researchers have used a procedure first developed for the treatment of cystic ovarian disease to sychronize estrus and ovulation. This procedure, known as the OvSync procedure, has been demonstrated to be as effective as breeding upon the detection of estrus. The purpose of this study was to determine if efficacy of the OvSynch procedure could be improved if used concurrently with a intravaginal progesterone insert (IPI; aka-CIDR).

Methods and Materials

Treatments were administered as described in Table 1. One hundred lactating dairy cows from the University of Illinois Dairy Farm were included in this study. Four cows were deleted for non-reproductive reasons. This study was conducted as part of a larger multi-station study (NC-113 Technical Committee).

Results and Discussion

Results are summarized in Table 2. OvSynch effectively prepared lactating dairy cows for insemination. As previously demonstrated, pregnancy rates per insemination were as high as pregnancy rates in cows bred at estrus. However, since all treated cows were bred, overall pregnancy rates are higher. Use of a intravaginal progesterone insert improved pregnancy rates. Therefore, if data from other stations concur with these results, the intravaginal progesterone could be a method of improving pregnancy rates in cows administered OvSynch. It should be noted, however, that OvSynch and the intravaginal progesterone insert have not been approved by the FDA.

(Tables can viewed in the PDF file)

Table 1. General procedures used to synchronize ovulation of lactating dairy cows

Table 2. Reproductive characteristics of dairy cows administered OvSynch or OvSynch plus the IPI for estrus synchronization

DOWNLOAD PAPER - EfficacyOf.pdf

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