Eric Valenzuela


Education: Bachelor of Science in animal sciences and industry (December 2020)

McNair Project: Determining the Stage of Embryo Loss due to Suspected Lethal Alleles in Beef Cattle (2019)

Mentor: David Grieger, Ph.D.

In dairy cattle, (Charlier, et. al. 2016) a segment of early embryo loss can be hereditary, specifically alleles that are lethal to the development of the embryo. It is likely that similar lethal alleles are present in beef cattle breeds. The focus of this study was to link known genetic pedigree to early embryo loss in beef cattle. The ability to successfully identify deleterious genes in an embryonic genome would provide early indication for greater selection against unwanted genetic parameters. This study included 10 cows from the Kansas State Cow-Calf Unit that were synched using a 7-day synchronization process. Only 3 of the 10 cows went into heat and were viable to take an embryo. Pregnancies were monitored for the following 42 days and closely analyzed for early embryonic loss. The purpose of monitoring pregnancies included determining the time of gestation for individual embryo loss and the attempt to collect aborted embryonic tissue for genetic analysis. Implications of this study included a delay in transferring embryos due to infertility in the first herd. The second herd utilized had numerous cows who had recently birthed calves and were not yet cycling. Due to the delay in the ability to transfer embryos, the results are incomplete.