A Novel Vaginal Mucosa Assay for Evaluating Estrous Cycle in Dairy Cows

Billions of people worldwide consume milk and dairy products every day, and the global demand for protein-rich dairy products is continually increasing, with the FAO estimating that the demand will increase on average, 2% per year at least until 2022. Dairy farmers are challenged to improve efficiency and increase milk production. Key to addressing this challenge is improving the dairy cow lactation cycle. Most U.S. dairy farms (88.4%) use artificial insemination (AI) to breed dairy cattle. This technology provides enhanced genetic improvement to dairy herds. For dairy farms using AI, inseminating cows either too early or too late in relation to ovulation results in poor conception, which in turn, leads to extended calving intervals reducing cow lifetime productivity and profitability. Detecting standing heat and even estrus is a challenge on its own, let alone determining the optimal moment to inseminate. These issues can lead to serious economic losses for dairy farmers. Oratel Diagnostics LLC (Oratel) proposes to develop a vaginal mucosa assay comprised of a simple straw with a filter inoculated with plant pigments that can be used easily on both large and small dairy operations to determine the optimal time for insemination. This assay can identify when cows and heifers are not at an optimal time to be inseminated, thus allowing farmers to delay insemination for a more optimal time, which will then improve conception rate and overall reproductive efficiency. This Phase I proposal will conduct feasibility testing of the technology on large commercial dairy herds (710+ cows) using timed breeding programs. The dramatic reduction in fertility observed for cows that give a dark green color response to Oratel VACA assay, (20 to 25 percentage points) supports the hypothesis that the assay developed by Oratel is capable of detecting a subpopulation of cows that will have significantly reduced fertility if inseminated. Based on these results, we propose that these cows could benefit by delaying their insemination during the same heat event, wait for the next heat, or initiate immediately a synchronization of ovulation protocol to maximize the likelihood of conception in a subsequent AI service. Thus, this technology creates an opportunity to make the decision of either inseminating cows or not after they have been detected in estrus or at the time of AI after synchronization of ovulation for TAI.