From Issue Winter 2021

For the Health of the Herds

MAFES researchers help small ruminant farmers in herd health

By: Vanessa Beeson

For the Health of the Herds

MAFES scientists are developing best management practices to diagnose and treat parasites in sheep and goats. (Photo by David Ammon)

Sheep and goat farming in the U.S., while a niche market, is holding steady with 5.17 million sheep and lambs and 2.6 million goats inventoried in 2020. The small ruminants are ideal across various production systems because they can use a variety of grazing lands, which may not be ideal for other animals, and still produce quality meat and milk. One thing many sheep and goat producers struggle with, however, is treating the animals for internal parasites, especially in humid regions such as the Southeastern U.S. As drug-resistance increases, producers need better ways to diagnose and treat sheep and goats for parasites in a production environment. That's why scientists in the Mississippi Agricultural and Forestry Experiment Station, or MAFES, aim to further establish best practices for this endeavor.

Dr. Leyla Rios, assistant extension and research professor in the Department of Animal and Dairy Sciences and MAFES scientist, is investigating parasite loads across five goat and five sheep flocks in Mississippi. From fall 2021 to spring 2022, the team will evaluate indicators of parasitism such as body condition score, age, body weight, fecal egg counts, and FAMACHA©, an indirect method to estimate the effect of barber pole worm (Haemonchus contortus) in small ruminant animals, which evaluates the color of the mucus membrane in the animal's eye. If H. contortus, a common parasite, is found, the animal will likely have anemia. A bright pink membrane indicates a healthy animal while a pale membrane indicates an anemic animal that is fighting off a parasitic infection.

Rios has traversed the globe as a small ruminant expert. The Venezuelan native is a former faculty member and researcher at the Colombian Agricultural Research Corporation and the Universidad Central de Venezuela, where she earned her bachelor's and master's in animal science and animal production and nutrition, respectively. She has studied small ruminant production throughout Latin America, in the Caribbean, in the U.K., where she earned her doctoral degree in nutrition and parasite interaction from the University of Edinburg and the Moredun Research Institute. Now, as a MAFES researcher and MSU Extension Service specialist, she is excited to help Mississippi farmers raising small ruminants, a production model she said is increasing in numbers in Mississippi. Rios said she hopes the work will help Mississippi's sheep and goat producers better manage parasite loads on their farms.

"Our research will help farmers identify better ways to sustainably manage parasite control while avoiding the increase of parasite resistance, which is a central problem worldwide in small ruminant operations," Rios said.

The current parasite level of the ten farms will be studied, where researchers will estimate parasite loads through fecal samples while assessing detection indicators. The team, which includes Lindsey Dearborn, master's student in the Department of Animal and Dairy Sciences, will then analyze the data to determine which indicators best estimate actual parasite loads.

Dearborn said she hopes the work will help farmers treat only the animals who need it, reducing the chance of increasing parasite resistance.

"Parasite control around the world is becoming such an important issue as parasite resistance is becoming a bigger problem," she said.

Dearborn explained there are three classes of anthelmintics approved for goats and sheep that are used to treat parasites, so producers are limited in what they can use.

"Misuse of these commercial dewormers has caused resistance, which as it increases can lead to production losses," she explained.

"Instead of producers simply treating all animals for parasites each month, we hope to provide quantifiable data that lets them know which indicators correlate best with actual parasitic loads, so they know which animals need to be treated."

The Titusville, Florida native grew up visiting Starkville and always knew she'd attend MSU.

"I always had an appreciation for MSU and loved animals and thought I wanted to be a vet. Of course, MSU is an amazing place to study animal science," she said.

Dearborn graduated with a bachelor's in animal and dairy sciences with a business and industry concentration from Mississippi State in Spring 2021. A love of both small ruminants and research inspired her to pursue a master's in animal and dairy sciences instead of applying to vet school. When Rios joined MSU in 2020, Dearborn leapt at the chance to study small ruminants under her.

"I realized I wanted to be more involved in research and industry and would also love to be a professor and I was always interested in sheep and goats," Dearborn said.

"I had horses in high school and the place where we kept them had a small goat farm, so I've always loved goats and wanted to work with them. I was really excited when I heard about Dr. Rios working with sheep and goats. I immediately sent her an email and asked if I could be her graduate student."

Rios is happy Dearborn reached out, noting that the graduate student is very dedicated in her work.

"Lindsey is proactive, intelligent, and works very hard. She is an important contributor to our team," she said.

The scientists are also conducting a survey to get to know the state's goat and sheep producers better in order to quantify and address their research needs.

"I'm excited to get to know the small ruminant farmers in Mississippi and show them we are here to help them because, ultimately, they are our clients. I look forward to helping them address issues with parasites but also address any knowledge gaps in small ruminant research in Mississippi by partnering with them in any way we can," Rios said.

This research is funded by the Mississippi Agricultural and Forestry Experiment Station. MSU collaborators on the parasite research include Dr. Rocky Lemus, extension and research professor in the Department of Plant and Soil Sciences and MAFES researcher, and Dr. Michael Pesato, assistant clinical professor in the College of Veterinary Medicine. On the survey project, collaborators include Dr. Laura Downey, extension professor in the School of Human Sciences; Dr. Gina Rico-Mendez, assistant professor in the Social Science Research Center; and Dr. Josh Maples, assistant professor in the Department of Agricultural Economics. Dr. Felipe Torres-Acosta, University of Yucatan-Mexico, and Dr. Jessica Quijada, University of Langston-Oklahoma, also contributed to the work.

Opposite: Brad Gilmore, Lindsey Dearborn, and Leyla Rios examine a sheep at Gilmore

Opposite: Brad Gilmore, Lindsey Dearborn, and Leyla Rios examine a sheep at Gilmore's Mississippi farm. (Photo by David Ammon)

Our research will help farmers identify better ways to sustainably manage parasite control while avoiding the increase of parasite resistance, which is a central problem worldwide in small ruminant operations.

Dr. Leyla rios

Behind the Science

Leyla Rios

Leyla Rios

Assistant Extension and Research Professor

Education: B.S., Animal Science, MSc., Animal Production/Animal Nutrition, Universidad Central de Venezuela (UCV); Ph.D., Interaction Nutrition-Parasites, University of Edinburgh, U.K.

Years At MSU: 1

Focus: Use of bioactive forages and plant extracts for sheep and goat parasite control and welfare of foraging sheep and goats

Passion At Work: Small ruminants are species easy to produce in small spaces, require a low initial investment, produce high-quality protein food for the human population, and can be produced with family manpower. On the other hand, gastrointestinal parasites cause the highest economic losses to small ruminant businesses and that is why we are looking into alternatives for sustainable parasite control.