Animal Science, Department of
Nebraska Beef Cattle Reports
Date of this Version
2018
Citation
2018 Nebraska Beef Cattle Report. University of Nebraska Extension MP105. Lincoln, NE.
Abstract
Most bovine estrous synchronization protocols utilize progesterone plus estrogen to control ovulation timing. A drug that inhibits estrogen production (Letrozole) may be an alternative, steroid-free synchronization method (not yet commercially available). However, low estrogen can negatively affect the health of follicles/oocytes and impact fertility. To determine its effects, Letrozole was administered intramuscularly while tracking follicle growth and circulating hormones. Letrozole response was variable. Two of three cows experienced delayed luteolysis/ovulation and extended progesterone production. This preliminary data indicates that Letrozole treatment allows normal follicle progression but drug response may vary and little is known about effects on oocyte quality.
Included in
Large or Food Animal and Equine Medicine Commons, Meat Science Commons, Veterinary Preventive Medicine, Epidemiology, and Public Health Commons
Comments
© 2017 The Board Regents of the University of Nebraska.