New research is showing that animal feed can carry major animal disease including African Swine Fever (ASF), says Scott Dee, veterinarian and director of applied research for Minnesota-based Pipestone Veterinary Services.
In a presentation to hog producers at the Banff Pork Seminar earlier this winter, Dee gave an update on a rapidly changing world of feed biosecurity in North America.
The concept of animal feed as a previously overlooked risk factor came to light following the introduction of PEDv into U.S. swine herds in May 2013.
Feed ingredients and prepared diets were not considered as potential vehicles for pathogen transport and transmission before then, and no standard biosecurity practices were in place even though swine facilities frequently received new products and supplies daily or weekly.
The link between diet and disease transmission has raised concerns that U.S. herds could become infected with foreign pathogens through contaminated feed and feed ingredients originating from countries with endemic disease and lax sanitation and quality-assurance procedures.
Feed can support viruses
Experimental data has already demonstrated that some feed ingredients, particularly soy-based products, can support the viability of at least three significant viral pathogens of swine (i.e., Classical Swine Fever or CSF, ASF, and PRV). ASF survival has been successfully confirmed in nine distinct feed ingredients, including three soy-based products, choline chloride, three pet diets, pork sausage casings and complete feed exported from China to the U.S.
Contaminated feed and feed ingredients are now widely recognized as likely vehicles for the transport and transmission of viral pathogens, highlighting the need for improved biosecurity policies and procedures for imported products intended for use in animal diets.
In Canada, restrictions are placed on feed ingredients imported from countries known to be positive for ASF virus that are known to enhance the survival of pathogens, predominantly soy-based products. The Canadian Food Inspection Agency has also established secondary control zones around all national seaports where these high-risk ingredients are received. After arrival, products must be stored under controlled environmental conditions for a specified interval to allow adequate time for viral decay before distribution to milling facilities.
The situation provides complex challenges, but also unique opportunities to advance agricultural biosecurity. Even though the risk of pathogen entry through contaminated feed ingredients may be low, the associated consequences related to a lapse would have extremely negative effects on animal agriculture and commerce.
However, new and emerging technologies are developing at an equally rapid pace and can often be leveraged to further enhance the management of these new risk factors at the transboundary and domestic levels. The use of some chemical additives has been shown to reduce survival of viral pathogens in products intended for use as animal feed ingredients.
The relatively new concept of “feed quarantine” is rapidly evolving, as production companies design storage facilities to safely accommodate incoming products and facilitate secure, long-term trade with a wider range of international partners.
Dee says unfortunately, despite the growing body of scientific evidence in support of the risk as it pertains to other pathogens, the risk of feed ingredients continues to be ignored, thereby continuing to expose U.S. agriculture to the risk of the introduction of foreign animal diseases via contaminated feed ingredients.