Some of our local Mennonites here in SE PA operate what has to be the world's biggest smorgasboard -- closest thing to a feedlot that I know. If you're in our neck-o-the-woods, stop by and I'll take your Dad for a visit to that feed trough. Although that's not what he had in mind, I'm sure he'd enjoy it.
Having worked for a number of years in one of the world's largest farm machinery manufacturer's, and having spent lots of time in Nebraska right next door to some big feed lots, you'd think I should know of someone??? Sorry, but all my contacts have long since moved on to other pastures. Hope someone else here can help you out.