check with a horse boarding enterprise. most are very picky about hay quality and many grow their own so they can have confidence in the quality of it. My boarding woman grows her own big bales and supervises every one opened up to be fed to the 27 horses she boards and if it isnt good enough, it goes to her cattle. She is quite strict, and thats why my Walker is there. These ladies are VERY picky about food quality. I never knew until recently 75% of horse owner/riders are women.