I will not buy meat from WalMart, sorry, I just don't trust them on that issue. Aside from that, I shop at both WalMart and Costco.
My Costco executive membership has been shredded and sent back to them... they are big Dem supporters and I am not giving them my money any more.
Also the prices aren't that good anyway compared to other places around here.... but I never told them that.