The aim of this project is to enhance our understanding of the ovarian, embryonic and uterine factors that regulate developmental competence of oocytes, pre-implantation embryo development and uterine conditions so that the declining fertility rates and increased embryonic losses among dairy cattle as well as beef cattle and sheep, can be overturned. Therefore, by reversing these declining rates of fertility, we expect to make agricultural production more efficient, profitable, and competitive. Impaired reproductive performance is an increasing problem and a major cause of reduced profitability for dairy and
meat producers. Decreased fertility rates cause reduced milk production over the lifetime of the animal, fewer calves for replacements and less extra income from selling the extras. Various genetic, physical, nutritional, and environmental factors impact ovarian activity, fertilization success, and embryo survival; however, further research is needed to understand the underlying mechanisms that affect fertility in cattle and sheep. With enhanced knowledge of the biology of ovarian function, animal producers, veterinarians, nutritionists, and scientists can work together to develop and implement new preventative and therapeutic reproductive management strategies, especially ones that are not drug-based. Improved animal reproductive performance is a key part of sustaining an agricultural production system that is highly competitive in the global economy. The research proposed here focus on several important areas. The team continues to conduct studies to identify novel genes and cell function that might contribute to predict oocyte quality. Specifically, how these genes influence the acquisition of developmental competence in the oocytes and how they regulate the initiation of gene expression in the embryo. The expression of factors that regulate luteal development, function, and regression are also central to improving female fertility in dairy and beef cattle. Likewise, environmental and metabolic stress negatively impact embryonic and fetal survival in cattle and sheep; and therefore, represents an additional area of research focus. Collectively, the information obtained from these studies will be distributed to assist producers with management decisions and strategies to minimize the detrimental effects of genetic, nutritional, and environmental stress on herd fertility.