by Courtney Llewellyn
Any person who has worked with animals knows coronaviruses are not new to livestock and poultry. In humans and birds, the viruses can cause respiratory tract infections; in cows and pigs, they can cause diarrhea.
Does the current COVID-19 global pandemic affecting humans give dairy or beef farmers any reason to worry? Physically, no, but there are other concerns.
Heather Simmons, DVM, Institute for Infectious Animal Diseases, said coronaviruses in livestock are not considered reportable diseases because their main effect is an economic burden on livestock producers. The diseases occur worldwide annually. Some of the most common coronaviruses found in production animals include scours and winter dysentery in cattle.
“What is very important to understand at this time is that we have been dealing with these diseases for a long time but as of yet, we have not seen cases worldwide transmitted from livestock to humans or vice versa,” Simmons said.
While coronaviruses have a high morbidity (rate of illness) in livestock, they are usually considered to have low mortality (rate of death). Coronaviruses affect either the respiratory system or the gastrointestinal system, depending on the species and the age of the animal. Bovine coronavirus (BCoV) was first discovered at the University of Nebraska in 1972, and it most often affects cows’ gastrointestinal tracts.
It most often affects calves, with diarrhea commonly occurring in animals under a month old due to a lack of obtaining antibodies (usually when the calf does not receive enough colostrum from the mother in order to build up immunity). Clinical signs include severe dehydration and diarrhea. There is also some evidence BCoV can cause mild respiratory disease or pneumonia in calves up to six months.
The other clinical syndrome, winter dysentery, is seen more in adult cattle. Signs include bloody diarrhea, loss of appetite and some respiratory signs. The virus is shed in the environment through nasal secretions and through feces. It’s often seen by producers in the winter months because the virus is more stable in cold weather.
Livestock producers should consult with a veterinarian for treatment, which typically includes a supportive therapy of fluids.
“I’m not aware of any impact on dairy products,” Dr. Theresa Ollivett, DVM, Ph.D., DACVIM, University of Wisconsin School of Veterinary Medicine, told Country Folks. “It’s primarily a problem for calves less than three weeks old … and occasionally will cause an outbreak of diarrhea in lactating cows. Most recover uneventfully.”
Because of the highly error-prone way in which BCoV replicates itself, along with the possibility of recombination between its isolates, the virus has a high potential to mutate, making it and other coronaviruses rapidly moving targets, according to John Ellis, Department of Veterinary Microbiology, University of Saskatchewan.
The consensus on the current coronavirus outbreak is that it came from Chinese wet markets, where people can purchase wild animals and eat them without great sanitary precautions. Fortunately, stringent food safety protocols in the U.S. ensure the foods people consume – including milk and other dairy products – are safe from these issues.
Unfortunately, food safety isn’t the only fear farmers will have to contend with.
The dairy markets – as well as all of the other markets – are closely monitoring the spread of COVID-19 and its potential impact on the economy and consumer behavior. Stock prices have been fluctuating wildly, and this month, for the first time since the financial crisis of 2007, the Federal Reserve called an emergency meeting and cut interest rates. If this strain of coronavirus continues to unsettle the markets, further cuts in the hopes of stimulating economic activity make take place.
This cut resulted in the U.S. dollar being weakened considerably – but that led to American exports becoming more competitive.
According to economic data, U.S. dairy product exports had a strong showing in January, with $546.2 million in sales. That’s only the second time in history that January sales topped $500 million. Liquid milk sales will likely see declines due to travel and trade restrictions, but powdered milk, cheese and butter sales are all looking up.
The international Organization for Economic Cooperation and Development, based in France, releases economic forecasts. In a recent forecast, their best-case scenario regarding COVID-19 predicted the pandemic is going to knock 0.5% off global GDP in 2020. While global trade may not affect all farmers, an economic downturn affects everyone.
Domestically, closed schools and businesses that regularly purchase dairy products may lead to a decrease in demand and sales, but parents and children who are essentially sheltering in place will likely need more dairy at home, so the impact may not be as large there for producers.
What this all boils down to is that coronavirus will most likely not be an issue for cows, but it may affect their caretakers for a while.