1a.Objectives (from AD-416):
To improve our understanding of the mechanism(s) by which pre-ovulatory estradiol concentration and a prolonged pro-estrus affect embryo development and pregnancy establishment in beef cattle.
1b.Approach (from AD-416):
Mechanisms controlling fertility of single matings in beef cattle are poorly understood, especially cows that exhibit estrus. The scientists involved with this agreement from both institutions will share data and research efforts to identify mechanisms controlling fertility and their effects on early embryo development, pregnancy establishment and maintenance. This research will include evaluation of serum estradiol and luteinizing hormone collected from cows around the time of ovulation and the role of these hormones on oocyte maturation, fertilization, early embryo development, and the ability of differentially developed oocytes to establish viable pregnancies. The USDA-ARS, Fort Keogh, Miles City, MT, has a majority of the cattle used for these studies, and the research involved with these studies will occur at Fort Keogh.
ARS scientist visited the Ohio State University to participate in a thesis defense and plan future collaborations. One additional project was completed this spring to evaluate the effects of specific hormone profiles during development of the cow’s egg. Analyses of these results are currently underway.