ALBERTA: New BSE cases blamed on ineffective feed ban

18.may.08
Edmonton Journal

EDMONTON -- In the mid-February cold, an Edmonton-area dairy farmer watched a thin, sickly animal struggle and finally go down. As required, the cow's head was sent for testing and a few days later, the country's 12th case of mad cow disease was confirmed.
This story says that Government officials were cited as saying the case was not unexpected, and five years after the traumatic discovery of bovine spongiform encephalopathy on Marwyn Peaster's northern Alberta farm, the public barely noticed case No. 12.
But it raised a few eyebrows among some ranchers and researchers. This animal was born in 2002, a full five years after the 1997 feed ban that was supposed to protect the Canadian herd from BSE infection.
In fact, of 12 BSE cases uncovered since May 2003, at least half are BABs -- born after the ban -- a development that raises serious questions about the efficacy of the 1997 feed ban which prohibited the risky practice of feeding rendered cattle parts to cattle.
Banning ruminant-to-ruminant feed reduces the chance of cattle ingesting the abnormal, disease-causing prion that causes the disease. (Feed made for pigs and chickens can still contain some rendered cattle parts.)
Critics say it took too long to get strict compliance with the 1997 ban and it took too long -- four years after the 2003 BSE crisis -- to implement an enhanced feed ban.
George Luterbach, senior veterinarian of the Canada Food Inspection Agency, was quoted as saying officials were aware the feed ban "was not 100-per-cent effective." First, the CFIA did not recall old bags of cattle feed that still contained rendered cattle parts, so it sat around for months.
Secondly, the ban created two feed streams, one for cattle that had to be free of cattle parts and one for pigs and chicken which was still allowed to contain rendered cattle parts. There was potential for cross-contamination on the farm, in the feed mill or in transport.
Luterbach says the 2003 BSE crisis made everyone, from farmers to feed operators, more diligent in complying with the ban. "It was a wake-up call for feed industry and livestock producers to be diligent and not mix feed," he was quoted as saying.
But it is still difficult. In December 2006, for instance, cattle feed that ended up on 113 Ontario farms was exposed to contamination in a rail car. The rail car was first used to ship bone meal for pigs and chicken feed, which contained rendered cattle parts, then was used to ship ingredients for cattle feed.
The story goes on to say that also, in January 2005, CFIA discovered some animal material in bags of cattle feed labelled free of animal matter.
In July 2007, CFIA took new precautions to protect feed by ordering slaughterhouses to remove cattle brains and spines -- called specified risk materials -- from all animal feed, not just cattle feed, and including pet food. (SRMs were removed from the human food chain in July 2003 shortly after Alberta's first case. CFIA did not go as far as the European Union, which banned all animal protein from being fed back to animals for human consumption.)
Canada's BSE rate is still in the low end of the spectrum and is not a human health hazard.
The story goes on to say that researchers at the new Alberta Prion Institute think it's a little more complicated. Two of the 12 cases, (including the 11th discovered last December on a beef farm east of Red Deer) are called "atypical," or spontaneous cases in much older animals, and are not caused by contaminated feed.
No one knows exactly what causes this strain of the disease, Steve Moore, the institute's scientific director and chairman of bovine genomics at University of Alberta was quoted as saying.
The enhanced feed ban will have to be maintained for the long haul, to make sure diseased prions from these spontaneous cases don't enter the feed chain.
The institute, established in 2005 with a $35-million grant from the Alberta Ingenuity Fund, is looking for ways to reduce the cost of disposing of the huge piles of cattle spines and skulls now being stuffed into private landfill sites by slaughterhouses.
Right now, SRMs are put into clay-lined landfill sites. That's fairly secure, says Moore, but scientists also know that when the abnormal prion bonds with certain minerals in the clay, its infectivity increases by 600 per cent.