In case you missed it, the USDA announced on 5 Feb 2010 it will abandon efforts to implement the National Animal ID Program, which would have required registration of every chicken in your backyard pen and every cow you milk for your family, right along with every commercial farm animal raised for food.
I realize they were putting forth an attempt to track diseased foodstuffs back to the livestock where it may have originated, but it was far too restrictive to small farmers and homeowners who raise some of their own food. My personal opinion is that most contaminated foods come from either poor sanitation in processing, or the practice of feeding dead/diseased animals and spoiled vegetable waste to the animals in huge feedlots. God forbid they should blame the big guys with deep pockets who buy legislation.
The USDA plans to explore alternative methods for tracing livestock. They hope the revised program will win more widespread support from farmers. Here's the USDA press release.