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Disease can reach hog herds through feed

Research says disease travels on feed.The hog sector is working to limit the risks

New research suggests that animal infections can come on feed.

North America’s livestock feed system continues to change to manage the risk of disease travelling on feed.

The changes have meant world-leading restrictions on feed imports to Canada and a decline in imports of soybean meal into the U.S. from areas of major swine diseases. It’s also meant that some large farms are adopting supplier-to-farm biosecurity systems for feed components.

Why it matters: Foreign animal diseases are a serious threat to the viability of livestock farms in Canada and biosecurity is one of the methods of reducing risk.

The first researcher to find that porcine endemic diarrhea (PED) could be carried in feed seven years ago says recent research has created similar concern about African swine fever (ASF).

Dr. Scott Dee, who works for Pipestone System, said that Canada has done a good job of restricting feed imports to limit risk of the disease. He singled out veterinarians Dr. Egan Brockoff from Alberta and Dr. Doug MacDougald of Southwestern Ontario Veterinary Services as leaders in developing systems to block feed ingredient imports from at-risk countries and improve bio- security protocols for all imported feed.

ASF is a highly destructive disease that has devastated China’s swine herds and in some European countries. Its arrival in North America would close borders in a sector that is highly dependent on exports.

Dee told the recent Banff Swine Seminar that China is rapidly rebuilding its swine herd and there is a lot of money involved.

“Gilts, anything that breeds, is going for $600 to $800 no matter the genetics,” he said. Cost of production for gilts is about $100, “so there are big bucks to be made.”

Pipestone System, the largest swine veterinary practice in the U.S., also provides management services for hog farms. It manages a 70,000-sow system in China, so they have a decent idea of what’s happening there, and Dee says it’s accepted in China that there’s transmission of ASF in feed.

Modelling ASF movement

Dee is part of a group of American epidemiologists and virologists that is modelling and tracking how ASF could be spread in North America.

They include virologist Megan Neiderwerder at Kansas State University who has shown that ASF can be spread in water and in complete feeds.

Feed is more of a concern, says Dee, because the dose of virus that pigs get in water is lower than they would get in feed. Pigs will eat many times per day and it is the number of consumption sessions that increases risk, not volume, he says.

Nine ingredients in hog feed were found to carry ASF, and many of them, at some volume, are imported.

Soybean meal is the biggest concern, compared to nutrients like amino acids, as it arrives at greater volume. In the United States imported soybean meal comes from three main countries, China, Ukraine and Russia — all with major issues with ASF.

Dee says it’s surprising that the United States – one of the world’s leading producers of soybeans – would have to import any soybean meal, but it is for specialty markets. Most of the imports from Ukraine were labelled as organic. The United States doesn’t produce enough organic soybeans to meet the needs of organic livestock.

“Putting our agriculture sector at risk due to 104,000 tonnes of soy is crazy,” said Dee.

Since 2018, however, Dee says the imports of soybean meal have declined significantly, a result which he believes comes from the risk information he and his colleagues have communicated.

Imports from China are easy to track as they mostly arrive through San Francisco. Imports from Ukraine are more challenging as they can arrive anywhere from New York, to New Orleans to Charlotte, N.C.

Feed mill dust and ASF

Dee has worked with a group in China that is examining how ASF moves in feed during an outbreak. Out of 28,000 samples of complete feed tested at three commercial feed mills, one per cent tested positive at one mill.

In tests of ingredients, two per cent of corn, wheat, rice and soybeans tested positive.

He says this is the first evidence of ASF viral DNA found in a feed system during an epidemic. There’s evidence in Brazil that senecavirus was found in the feed system too.

He says China has tightened up its grain-handling practices to limit exposure of grain to the environment.

At the same time as the Banff Swine Seminar in early January, a truck was making its way around the United States, on a grand tour from Minnesota, Colorado, to Texas, to Florida, up the east coast and then back under the Great Lakes to Minnesota. The feed on board had been contaminated with PRRS, PED and senecavirus. After a 21-day drive and almost-10,000-km trip, the samples will be tested to see which viruses survived.

Feed biosecurity tightened

There’s overwhelming financial advantage in importing large volumes of certain feed additives from China, so instead of stopping that practice, Dee says Pipestone set up a system for amino acids and vitamins that has built-in biosecurity protocols that are audited right from the manufacturing plant in China to warehouses and shipping all along the chain into the United States.

SAM Nutrition, an American company has embraced what Dee calls “responsible importing” and when the product arrives from China, it is stored in a quarantine room in a warehouse.

It costs Pipestone about three cents per pound to pay for the increased bio- security, but importing from China saves them from five to 15 cents per pound.


What are Canada’s new import controls

The Canadian Food Inspection Agency (CFIA) has strong import controls for live animals coming into the country under the Health of Animals Act, but had no import controls over plant material for livestock feed.

As a result, the CFIA says a new policy was created that allowed marine ports to be declared secondary control zones relating to plant material livestock feed imports.

Grains and oilseeds and their ground products (such as soybean meal), from a list of countries that have had ASF in the past five years and haven’t been declared clear of the disease, are subject to restrictions.

Import permits have to be obtained before such products can be imported.

Questionnaires for importers include queries on everything from plant products involved in the feed, the temperature at which the feed or ingredient is processed at the plant where it is made and what other products the feed or ingredient will come in contact with during transportation.

This article was originally published at Farmtario.

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