Theses and Dissertations

Issuing Body

Mississippi State University


Larson, Jamie

Committee Member

Lemley, Caleb O.

Committee Member

Hopper, Richard M.

Date of Degree


Document Type

Graduate Thesis - Open Access


Animal Science

Degree Name

Master of Science (M.S.)


College of Agriculture and Life Sciences


Department of Animal and Dairy Sciences


Progesterone is essential for the maintenance of pregnancy in cattle. Recent trends in decreased reproductive efficiency in dairy cattle have led researchers to believe that increased catabolism and decreased peripheral concentrations of progesterone are at fault. The objective of this study was to determine if the induction of an accessory corpus luteum (CL), via human chorionic gonadotropin (hCG), alters blood perfusion of CL, peripheral concentrations of progesterone, or hepatic steroid inactivating enzymes. We hypothesized that the induction of an accessory CL would decrease blood perfusion of the CL, decrease peripheral concentrations of progesterone, and increase clearance of progesterone in the liver. Total blood perfusion of the CL was increased in cows with 2 CL compared to cows with 1 CL, but concentrations of progesterone and hepatic enzymes did not differ. Overall, the increased blood perfusion in cows with 2 CL did not alter concentrations of progesterone or progesterone clearance.