#ResearchLife

Discovery, collaboration, and the unexpected. Just another day in the lab for Carrisa Womble ’19.

Goodnight Scholars Program: Talk about your research with Dr. Poole in the Department of Animal Science.

Carrisa Womble ’19: My research with Dr. Poole involves fescue toxicosis and the mechanisms through which it affects beef cattle reproductive performance and immunology. Fescue toxicosis is a condition that occurs when cattle graze pastures containing KY-31 Tall Fescue, a variety of fescue that has a symbiotic relationship with an endophytic fungus. While this relationship is beneficial to the plant by increasing its drought tolerance and heat resistance, the ergot alkaloid mycotoxins that the fungus produces cause chronic decreases in the growth and reproductive performance of the animals that are consuming it. This summer, I was given the opportunity to investigate the impacts of fescue toxicosis and protein supplementation on the post-vaccination immune responses of beef calves. If immunity is suppressed in calves affected with fescue toxicosis, a poor immune response to early vaccinations could predispose these animals to a higher risk of disease later in life. However, if protein supplementation was available, could it mitigate some of the negative effects of fescue toxicosis? I traveled with the Poole Lab to the Butner Beef Cattle Field Lab in Bahama, North Carolina on a weekly basis to collect blood samples, body weights, heart rates, respiratory rates, rectal temperatures, surface temperatures, core body temperatures, blood pressures, hair coat scores, hair shedding scores, caudal artery diameters, and caudal vein diameters on 36 six-month old Angus steers that were randomly assigned to receive either an endophyte-infected fescue diet or non-infected fescue diet and either 14% or 18% dietary crude protein. The diets were fed for a total of 63 days, with vaccinations being administered on days 28 and 42. Our data show that protein supplementation had mixed effects on the physiological responses of steers experiencing fescue toxicosis; it proved to be beneficial in some cases, but less so in others. We are still in the process of analyzing antibody titers and circulating hormone concentrations, and once completed, we hope these data will give us a better idea of how the immune response is being affected in animals experiencing fescue toxicosis.

What made you interested in working on this research with Dr. Poole?

Initially, it was Dr. Poole’s contagious enthusiasm for bovine reproductive physiology that led me to join his lab as a second-semester freshman. It wasn’t until I took Dr. Poole’s reproductive physiology lecture and laboratory courses my sophomore year that I was able to fully appreciate the intricacies of reproductive physiology. Learning about the roles of hormones and how their interactions make reproduction possible was so fascinating! Additionally, the more I learn about fescue toxicosis, the more I am in awe of how something as seemingly innocuous as the grass our cows eat can have such a profound effect on their reproductive performance, growth, and potentially their immunity.

What was your proudest achievement during your time in Dr. Poole’s lab?

My proudest achievement during my time in Dr. Poole’s lab was receiving a $2,500 research grant from NC State’s Office of Undergraduate Research to conduct my research on fescue toxicosis, protein supplementation, and post-vaccination immunity. After submitting a budget and a four page proposal to the summer research grant application pool, I was so excited to learn that my project was selected for funding. Thank you, Office of Undergraduate Research!

First and foremost, this experience taught me that research is not an individual endeavor, but a group collaboration. This project was truly a team effort!

What did this experience teach you about undergraduate research?

First and foremost, this experience taught me that research is not an individual endeavor, but a group collaboration. This project was truly a team effort! Thankfully, I belong to one of the best and most supportive lab groups on campus, although I may be a bit biased. This experience also taught me that not everything in research always goes as planned. Sometimes you’ll begin a week late, sometimes sample collection days will take twice as long as you thought they would, and sometimes your last steer to sample for the day will go crazy and take longer than the previous three animals combined. But in the end, it’s always worth it.

How does this research tie into your professional goals?

After graduation, I hope to attend veterinary school to earn my DVM and then pursue a Ph.D in immunology or a dairy science-related field. My ultimate goal is to have a career in academia that involves a combination of research, teaching, and dairy cows. Being a member of Dr. Poole’s research lab and being involved in this research project has and will continue to be one of my most meaningful undergraduate experiences that will shape my future decisions concerning higher education and my career.

What’s next for you?

Junior year! As I begin my third year in the animal science program, I will continue my work in Dr. Poole’s research lab, see this project to completion, serve as a teaching assistant for Dr. Poole’s reproductive physiology laboratory course, and so much more. As always, I am so thankful for the Goodnight Scholars Program making my summer research experiences possible.

Photography credit: Carrisa Womble/Goodnight Scholars Program