Animal Science, Department of


Date of this Version



Published in 2012 Beef Cattle Report (2012) p. 28-29. Copyright © 2012 The Board of Regents of the University of Nebraska.


The environment that the oocyte develops in (follicle) and the mRNA that is produced (mRNA abundance) during development were examined. Androgen levels within the follicle were higher in heifers (≤ 2 years) that never established a pregnancy compared to cows that stayed in the herd at least 3 years and had at least one successful pregnancy. These high androgen levels were associated with increased abundance of several candidate mRNAs in the cumulus-oocyte complex (COC), which includes the oocyte and somatic cells immediately surrounding the oocyte, isolated from the dominant follicle. The data suggest that androgen levels represent a marker for oocyte quality which could be used to select for females to retain in the herd.