Production of Recombinant Gonadotropins to Increase Fertility in Beef Cattle

Economic viability of beef cattle operations is dependent upon efficient production of calves whichdepends on reproductive efficiency of the operation. However numerous factors limit reproductiveefficiency in beef cattle including lack of cyclicity and difficulties in managing ArtificialInsemination (AI) programs including efficient utilization and fertility of AI.One solution is combining AI with precise synchronization of the estrous cycle termed timed AI(TAI). These programs induce cyclicity in non-cycling cows and allow all cows to receive AI onfirst day of the breeding season. However optimal fertility is only achieved when cows haveoptimal follicle growth at the end of the TAI program which requires exogenous gonadotropichormones usually equine chorionic gonadotropin (eCG). In this USDA SBIR research projectScienss Biotechnology (SB) proposes to:1) Develop vectors and cells that are necessary to produce recombinant gonadotropins includingeCG bovinized long-acting luteinizing hormone (LH) and follicle stimulating hormone (FSH).2) Evaluate biological activity for the recombinant and native proteins using in vitro assays for LHand FSH activity.3. Determine the in vivo activity for native eCG recombinant eCG recombinant bLH recombinantbFSH and the combination of bLH and bFSH in a rat bioassay.The scientists at SB are trained in the molecular biology cell culture and whole animal skills thatwill be required to complete this project. Successful completion of Phase I Objectives willdemonstrate feasibility of this approach for production of biologically-active gonadotropins. Thiswill allow SB to prepare for future projects that will up-scale the production of recombinantgonadotropins test the gonadotropins in cattle and will eventually allow governmental approval forcommercial sale of these products in US Brazil and other markets.