Do yous who feed pork freeze it (for what is it 72 hours or 4 days or something) first to make sure all the parasites & such are killed?

I do freeze most of my meats for at least 4 days before feeding them, but sometimes I don't if they come from a reputable butcher or the like.
I've never fed a lot of pork, I've always been scared to as I've heard so many bad things about it, being a "dirty" meat.