I would like to take issue with one of your comments, Dryland.

You said that dairy farmers do not keep their cows as long as beef producers.  From my perspective, I think you have that backwards.  From what I know, it seems that - around here at least - feeder steers are going to market around 18 months.  Dairy cows are not coming into production until 22 months at the very earliest, and 24 months would be more realistic.  And I think it is common to keep a dairy cow 3 years of production - and I am sure some dairy cows are kept longer. 

It seems to me that if a beef feeder steer is going to market at 18 months, it is possible that some of these beef feeder steers have the same potential for atypical BSE, but it is not showing visual symptoms before they go to slaughter, and so there might be more cases, just not being caught.

I have one more question.  Do you know the age of each animal that has been caught with BSE?  I have not looked it up, but maybe someone can speak to this.  If my memory is correct, that cow from Canada that was found a few years back was an older cow - maybe 8 years old??  

Is it possible that this variant is a lot more common than we believe, and more common than we are finding, simply because animals - both beef and dairy - are going to slaughter at an age young enough that we are just not seeing the symptoms show.  Just some food for thought.