The safest beef or chicken is Grass Fed. Unfortunatly it is also expensive. I get mine from my local farmer and the local farmers market.
I wrote this article on my research.
Why All the Fuss About Grass-Fed Meat?
http://coconutcreamcare.com/2012/06/26/why-all-the-fuss-about-grass-fed-meat-2/
We are a step away from eating tofu.
It can be the safest but I couldn’t buy enough to support my two teenagers.