What great information!
What changes are you seeing in your horses?
Example- we had a "chiropractor" come to the barn to work on some local horses and stay with the BO. He claimed that the supplements did nothing, that you needed to give them the shot, and that it would "loosen the skin" to make them look like they gained 20lbs of muscle. He said the symptoms of selenium deficiency were poor hooves and the "frizzle" hair at the tail head (looks like they rub their tail).