Switching from pasturized milk to raw milk?

Hello people,

I've been using store bought pasturized milk for my kefir grains for a few months, but I now have a source of raw milk that I plan to be using for the kefir, among other things.

Do I have to do anything special before I switch and start using the raw milk with the grains?

What about all the hormones, Antibiotics , and other garbage that is in the pasturized milk? Is it likely that the kefir grains have absorbed a lot of these poisons? If so, should I just get new grains?