I've heard some blatantly incorrect statements in my time, but that one has to rank in the top 10. You have my permission to completely ignore anything the person who came up with that says ever again.
Whey protein is derived from milk.
What supplement manufacturers do is separate the protein out of that liquid using a wide variety of methods. The danger of contracting mad cow disease from a whey protein powder is extraordinarily low. You probably have better odds of winning the lottery every day for a week. Messages entered in all CAPS will be deleted. Review your message and its format prior to posting.