Theses and Dissertations
Issuing Body
Mississippi State University
Advisor
Larson, Jamie E.
Committee Member
Rhinehart, Justin D.
Committee Member
Ryan, Peter L.
Date of Degree
8-6-2011
Document Type
Graduate Thesis - Open Access
Major
Agricultural Life Sciences
Degree Name
Master of Science
College
College of Agriculture and Life Sciences
Department
Department of Animal and Dairy Sciences
Abstract
The objectives of this study were to determine whether conception, ovulation rates, presynchronization rates, or follicle and CL characteristics were altered after modifying the Double-Ovsynch (DO) protocol to include human chorionic gonadotropin (hCG) compared to the conventional DO protocol in dairy heifers and lactating dairy cows. We hypothesized that replacing the first injection of gonadotropin releasing hormone (GnRH) in the DO protocol with hCG would increase the proportion of females that ovulate, thus improving the presynchronization rate leading to increased conception rates. Ovulation rates were increased in cows administered hCG compared to GnRH, but subsequent synchronization, and conception rates did not differ between treatments. A greater proportion of hCG-treated cows tended to fail to have undergone luteolysis compared to those treated with GnRH. In conclusion, no improvement in overall fertility was achieved by replacing the first injection of GnRH in the DO protocol with hCG.
URI
https://hdl.handle.net/11668/17842
Recommended Citation
Binversie, Joseph Andrew, "Modifying the Double-Ovsynch Protocol to include Human Chorionic Gonadotropin to Synchronize Estrus in Dairy Cattle" (2011). Theses and Dissertations. 3173.
https://scholarsjunction.msstate.edu/td/3173
Comments
presynchronization||hCG||Double-Ovsynch