Hueston: More needs to be done with mad cow
'Perceptions become reality'
By Janet Kubat Willette
ST. PAUL -- USDA acted aggressively to protect the nation's food supply after the mad cow discovery, William Hueston says, but there's still more to do.
Hueston, director of the University of Minnesota Center for Animal Health and Food Safety, served on an international panel of experts convened to evaluate the agriculture department's response to the December discovery of a cow infected with bovine spongiform encephalopathy in Washington.
The five-member panel recommended that all specified risk materials be excluded from human and animal food supplies. Specified risk materials include: Brain and spinal cord of all cattle older than 12 months; skulls and vertebral columns of cattle older than 12 months, and intestine from pylorus to anus.
The experts also suggested that slaughter and carcass-dressing procedures be brought in line with international standards. Banning advanced meat recovery and mechanically recovered meat systems should be considered, they said.
The panelists said it's imperative that USDA find ways to test downer cows that are no longer allowed in the food chain, and also find ways to dispose of carcasses. The U.S. surveillance program must be extended to measure the extent of the problem, now that BSE has been found in the North American cattle herd, the panel wrote.
Hueston said the country is in an interesting position.
"Most people probably don't realize if we don't test a whole lot of cows, the rest of the world will assume we have a lot (of BSE) and are afraid to look," he said.
U.S. cattle producers have to deal with the real issue of BSE and also the perception, Hueston said.
"In the absence of hard data, perceptions become reality," he said, "and there are some who want to encourage the perception that it's widespread."
So, in a way, the nation needs to test more to defend its status.
Hueston says the best way to get the most information for the least amount of effort is to focus on testing animals born in 1997 and before. Both the U.S. cow and the one in Canada diagnosed with BSE in 2003 were born in 1997. Prior to 1997, there weren't any controls on what cows and other ruminants could be fed and recycling of BSE agents could have occurred, he said. Contamination can occur with the consumption of an infected particle the size of a peppercorn.
On-farm controls are vital to keeping the food supply safe, Hueston said.
"The single biggest most important thing is to know their feed supplier; this is a disease that is transmitted through animal feed," he said.
Cattle, sheep, goats and buffalo should only be fed feed that is produced for ruminants. They shouldn't be fed pig, poultry or pet feed. If farmers have cattle and non-ruminant animals on the same farm, they may want to consider buying a second grinder or not using ruminant meat or bone meal in poultry or pig feed.
"You really want to prevent the recirculation or recycling of the BSE agent," Hueston said. "The challenge becomes how do we protect the cattle population while still taking advantage of every economic feed supply for pigs and poultry."
Second, it's important to establish a relationship with a veterinarian to follow up on sick cows. The nation already has surveillance for brain diseases related to rabies, which can transfer from animal to person, Hueston said. If veterinarians see cows acting oddly, they can sample deceased animals' brain tissue for both diseases.
To read the panel's report, go to http://www.aphis.usda.gov/lpa/issues/bse/US_BSE_Report.pdf
A World Health Organization report, "Understanding the BSE Threat," can be found at