I only have three hens.
I only have three hens. About 4 months ago they began to have dirty butts. I used the Ropa product in their drinking water. Four days latter the had nice clean tails again.
I have been using this product every other day. I put 10 mil in three quarts of drinking water. I have been doing this for a couple months. My hens look great and they are their bossy selves.