I've bought fresh bales of hay from three area farmers/feed stores. All claimed to be selling meadow grass or bluegrass. One bale from one farmer was loaded with alfalfa. What really bothered me was that he sells a large volume of it to rabbit owners. I donated the whole bale to my local animal control and told them there was a high percentage of alfalfa in it. They said they get in a lot of bunnies so they understood that it should not be fed to adults guinea pigs or rabbits. If it wasn't too costly, I'd donate it. If it cost a lot, I'd return it for a refund since you don't want to feed that to adults.