It isn't just the protein content you look at. Rats need fat in their diet as well. You need to look at the fat content. By the way keep in mind high protein food doesn't just effect their hair it will also cause liver damage long term if used too much. That is extremely painful for a rat. They will bow up and be real sluggish because they are in such pain.
Thats pretty high in protein. But then again, dog food has about that same amount and there's tons of people who use it with no problems. Just don't buy cheap stuff. I'm sure you'd be fine if you're using the rats for feeding purposes. Keep in mind rats are scavengers and eat anything they can find out of captivity.