Synchronized ovulation with a novel triptorelin gel delivery system for use of fixed time AI in MATRIX treated gilts.

The success of the US pork industry depends upon high fertility in the breeding herd. Unfortunately, sow culling rates of 50% force producers to maintain large pools of replacement gilts. Until the progestagen, Matrix (altrenogest), was approved by the FDA there was no product available to synchronize the estrous cycle of females in the gilt pool. Greater than 85% of gilts display estrus within 4 to 9 days after withdrawal of Matrix. Unfortunately, the 4-5 day spread in estrus synchrony precludes use of fixed-time or single service AI. Therefore, an additional treatment to more precisely control ovulation is needed so that all gilts in a group may be inseminated without regard to estrus. The overall objective is to develop a method to control time of ovulation in Matrix treated gilts. The new OvuGelTM treatment has successfully synchronized ovulation in weaned sows through delivery of a GnRH agonist in a slow release gel by an intravaginal delivery system. Phase I studies will determine the minimum effective dose and most effective time to administer OvuGelTM after withdrawal of Matrix in gilts. The direct economic benefits of this system include: decreased labor, feed and facilities costs, decreased number of boars, decreased days a female is not pregnant or not lactating and increased litter size. Indirect effects will also decrease consumption of natural resources and the environmental impact associated with swine production. Phase II studies will move application to commercial gilt replacement systems and work to further improve the OvuGelTM intravaginal dosing applicator.