Jane Christopher-Hennings craves the science side of veterinary medicine, which has benefited the state of South Dakota and its livestock industry.

Christopher-Hennings retired at the end of January as director of the South Dakota Animal Disease Research and Diagnostic Laboratory and head of South Dakota State University’s Veterinary Biomedical Sciences Department. She came to Brookings and SDSU as a postdoctoral student in 1990.

The timing of her arrival to South Dakota coincided with the emergence of a swine disease that was, for the lack of a better name, called “mystery swine disease.” Hog producers now know this as porcine reproductive and respiratory syndrome. But thanks to Christopher-Hennings and many researchers like her, strides have been made.

Christopher-Hennings says she and researcher Eric Nelson “did a lot of the initial PRRS work to develop some of the first monoclonal antibodies and tests to detect PRRS.” Nelson is assistant department head of the SDSU’s Veterinary Biomedical Sciences Department.

Hog farm mystery

Similar to working on a crime scene investigation, Christopher-Hennings sought the cause behind a case of PRRS at a South Dakota hog farm decades ago. The mode of introduction was a mystery, as no new pigs had entered the farm. The only variable brought into the farm was boar semen, and at the time, PRRS transmission through semen was an unknown.

Normal methods for isolating viruses in samples did not work with boar semen. “The semen is pretty toxic to the cell monolayer that you try to grow the virus on, so it would be destroyed before you could really tell whether there was virus there,” Christopher-Hennings says.

So she developed a test based on a polymerase chain reaction to detect the PRRS virus in boar semen. Though PCR tests are a common method used today in research, back in the early 1990s, it was relatively new technology. PCR was invented in 1983 by an American biochemist.

“At the time, we didn’t have a lot of PCR tests going,” she recalls. “In fact, there was one used on a really limited basis for Johne’s disease back then. It was really new technology. I kind of learned from scratch and reading a lot of papers. There had been work done with equine arteritis virus. So I looked at a lot of those kinds of papers. I like the investigation part.

“When you’re trying to figure things out, especially in research, if you don’t succeed the first time, you keep looking at different avenues to make something work. And the PCR worked, and it took off, and we started it at the diagnostic lab,” she says.

Those original PCR tests prompted the origin of the molecular section at the Animal Disease Research and Diagnostic Laboratory, which now runs more than 200,000 tests a year.

Established in 1967, the laboratory, as its name implies, combines research with diagnostics. “You’re not just spitting out results,” Christopher-Hennings says. “You’re developing new tests; you’re learning about how the tests can be used in different circumstances.”

While located on the SDSU campus, the laboratory works in conjunction with the South Dakota Animal Industry Board. The lab is funded mainly through user fees from producers and veterinarians who submit samples, as well as funding from the state Legislature.

Helping crack the PRRS mystery is one career highlight for Christopher-Hennings; another is overseeing the development of the new Animal Disease Research and Diagnostic Laboratory completed in 2020 at a cost of $60 million. Once the new laboratory was operational, the Veterinary and Biomedical Sciences building was renovated for primarily research purposes and some teaching. She has been department head and the laboratory’s director since 2013.

Retired, but not done

Even though retired, Christopher-Hennings will work part time on grant projects. One such project took her in March to Germany’s Friedrich-Loeffler-Institute, which is similar to the Plum Island Animal Disease Center off the coast of New York. This particular project involved inoculating boars with African swine fever to study the virus in commercial boars.

“Then we’ll look to see where [ASF] is in serum and semen and oral fluids over a 90-day period of time,” she says. “Then we’ll also inoculate sows at Day 7 and Day 90 to see whether it’s actually transmitted by artificial insemination.”

Veterinary beginnings

Her interest in the science behind veterinary medicine started when she worked for a veterinary clinic during high school near Madison, Wis. “It was a lot of routine spays and neuters and vaccinations, and I wasn’t so much interested in that,” she says. “I was just interested in the medical aspect of it and how exciting that was, and how it covered so many different areas, which is still interesting to me today.”

After getting her undergraduate degree from the University of Wisconsin-Madison, she received her veterinary degree in 1983 at the University of Minnesota, and during that time she worked at the veterinary school.

While a vet student in Minnesota, her first association with SDSU was visiting the late Al Leman, a well-known veterinarian there. But it wasn’t until she was in private practice in Rapid City, S.D., that she became more familiar with SDSU. “We actually worked a lot with wildlife, as well as small animals,” she says. “We sent samples here to the virology department and histopathology, samples of tumors and things like that.”

Christopher-Hennings has gained a lot from her veterinarian career, and she has been open with students about the vast opportunities in the field. “I’ve told students that you can be like I started out, in private practice; you could be a researcher, which I’ve been for over 20 years; and you can be an administrator. And so there’s any number of options within the veterinary career that are pretty exciting,” she says.