New research from the Kansas State University College of Veterinary Medicine provides the first investigation into how feed and feed ingredients may be playing a role in the spread of two swine viruses of global significance.
The first report of classical swine fever virus and the pseudorabies virus in feed ingredients subjected to different environmental conditions mimicking trans-Pacific shipment has been published, according to a Kansas State news release.
Both viruses are endemic to areas of the world where feed ingredients are manufactured and imported into the United States each year.
Currently, U.S. commercial swine are free of both because of costly eradication programs completed in 1978 and 2004, respectively. Reintroduction of those viruses into U.S. swine herds would be devastating.
There are concerns that feed ingredients incorporated into swine diets may serve as new sources for the spread of animal diseases, with economic and welfare significance. Recent changes in pseudorabies strain virulence and classical swine fever geographic distribution are of great concern for the trade-limiting diseases.
The route of introducing and transmitting swine viruses through feed has been recognized since the 2013-14 outbreak of porcine epidemic diarrhea virus. But the stability of the classical swine-fever virus and the pseudorabies virus in imported feed ingredients had yet to be investigated.
In the study, Kansas State researcher Megan Niederwerder found that both viruses survived for the length of the 37-day model in feed. The pseudorabies virus had increased stability across a broader range of feed ingredients when compared to classical swine fever virus.
The pseudorabies virus was detected in nine of the 12 tested ingredients at the conclusion of the simulated voyage — conventional and organic soybean meal, lysine, choline, vitamin D, moist cat and dog food, dry dog food and pork-sausage casings.