Some states, due to trich, opens, by law, must be sold terminal.
I definitely would not want to be the one traced back to an out break of trichinomus.

I believe, in South Dakota even non virgin bulls are destined for the rail.

I can only imagine the damage done by an infected bull turned out on your clean cows.
When it hops the fence to the neighbors............... better have a deep check book.

Just my expert opinion.....and I am an expert on My Opinion  :) 

Big kill tags are on them cows for a reason.