For several weeks, USDA investigators have been searching for some 81 cattle that were the herdmates of the Holstein cow found infected with the disease. A total of six American herds have now been quarantined.
The USDA said yesterday that it believes at least three herdmates of the infected cow were sent to a dairy farm in Tenino, Washington and at least six went to a farm in Connell, Washington. That means investigators have found 23 of the cattle they sought.
However, according to a Reuters report, the total number of Canadian animals the USDA is trying to track increased to 98 on Monday after officials said they confirmed a second group of cattle had been imported from the same Alberta farm where the infected cow was born.
US agriculture secretary Ann Veneman is scheduled to testify today at a House Agriculture Committee hearing on the USDA mad cow investigation.
Meanwhile, a USDA-led delegation left Washington yesterday to meet with officials in Japan and South Korea, two of the biggest buyers of American beef until mad cow disease was discovered in Washington state last December. More than 40 nations have halted US beef imports, an industry valued at some $3.2 billion annually.
It would appear that the US delegation faces a stern challenge in trying to persuade officials that US safety measures are sufficient. According to Japanese media reports, the agriculture, forestry and fisheries ministry issued a report on Monday stating that there no assurances can be made that more cases of mad cow disease will not be discovered in the United States.
"There is no guarantee that mad cow disease will not occur in the US from now," the report says, based on the findings of a team of Japanese experts who returned home Sunday after visiting North America.
The US has come under criticism for apparent holes in its surveillance system. According to USDA records, no BSE tests were carried out on commercial cattle in Washington State in the first seven months of 2003.