Protein Allergies

I was reading a recent Q & A with Charles Poliquin and he was talking about how most bodybuilders develop allergies to certain proteins like beef, eggs, chicken after consuming them over and over again. He recommended eliminating them from your diet for up to 6 weeks and replacing them with other proteins like fish, buffalo, shrimp, etc.
I’m curious how I can get tested for allergies to various proteins and what are some good alternatives to eggs, chicken and beef?
He also recommended rotating the protein shake everyday using whey/casein, liver, goat, chick pea and rice.

Any thoughts??

I think the best idea is to try and get protein from different sources as much as possible so that you don’t develop intolerances…

Ie, eat beef, chicken fish, beans, whey, cottage cheese, oatmeal, peanut butter… mix it up