You can but as you will hear over and over, whole foods protein sources are always better! Our bodies were designed to process and operate on whole foods. Your gains and progress will be MUCH better this way as well. Its kind of like buying a brand new high peformance designer sports car and then putting cheap 83 octane gas in it... sure, it will get you from point a to b on it but its not going to be the same performance you'd get if you filled it up with high grade 93+ octane fuel.
Also, if your using more then 1 shake to plug the holes, make sure you are using a sust release or slow digesting form of protein.