Honestly I would not risk it, but that's my choice. I do believe DE has it's benefits, but not as a sole wormer. Don't get me wrong, you may never have a problem if you never worm at all, but in larger flocks, or if you have a lot of wildlife such as birds etc. and you flock free ranges, I would use a chemical wormer, especially in Peafowl. I personally have not had much luck with DE with a large flock, but that's just me.