We have low selenium in this area and can buy a prescription mineral at our local Farmers Coop, that is higher in selenium than what is allowed in over the counter minerals. The Coop has a Vet on their payroll for this. It must work, because I can't recall a "dumb sucker" in recent history. Your post gave me a chuckle Jeanne. When I was a kid, "You dumb sucker" was an insult usually delivered to a sibling or cousin in anger. I never really thought about where that insult came from until I read your post. I was raised around dairy cattle and I do remember the frustration when one was slow to suck.