If you don't want to include animal products in your diet for religious or ethical reasons you can purchase vegan protein supplements that are based on brown rice, gemma pea, hemp and alfalfa.
I have used the vega sport protein supplement in before and it's not bad tasting at all. It's based on gema pea and hemp protein.
I would stay away from soy protein as it is estrogenic and very genetically modified.
there are plenty of vegan lifters and bodybuilders. is it harder? yes.. can it be done? ummm.. yeah, it has been done and there are some hardcore vegan guys and gals out there
i would check out some of their youtube channels where they have suggestions