The protein percentage is on the guaranteed analysis tag of all animal feed sold. I think it is also on the nutrition portion of any human food too.The only parasite that is showing up is coccidia. My practice doesn't like to overuse antibiotics with the worry of resistance but I've not used ab's on these guys yet. Not sure the protein?
With chicken feed, it is often even in large print on the bag itself.
I never buy a bag of feed without verifying the protein % and mill date at a minimum.