I'm having quite a bit of trouble with my black angus cows getting watery eyes that leads to the white ulster on the eye. I have taken several to the vet to get a shot in the eye lid. Thee are a couple more that I seen this morning that had the start of a watery eye . What can I do to help stil this? Anything I can mix with their feed or mineral to help. Do I need to feed more IGR? Thank you for the help