December 15, 2005

Dirty feed bins may be BSE cause

Dirty feed bins are the most likely cause of BSE in cattle born after July 1996, veterinary scientists say.

Though a bonemeal ban for ruminant rations was introduced in July 1996, a number of cattle born after that--known as BARB (born after the reinforced ban) cases--have also developed the mad cow disease.

Investigations revealed that a possible source of infection never identified precisely, is in the feed bins that had not been thoroughly cleaned for years, said Scotland's chief state vet Charles Milne on Dec 13.

He explained that "as little as 1 milligram of BSE-infected brain tissue has been enough to infect a calf". He also added that in some of these herds, feed was stored in feed bins that were in use before August 1996, and "had never been cleaned".

Farmers must now ensure that feed bins are cleaned routinely and thoroughly, particularly those in use before August 1996 and not cleaned out since.

BSE cases reached a peak in the early 1990s with more than 200,000 cases a year. Fewer than 200 a year are found today.