Cow Magnets

This has nothing to do with Niwa but....
Did you know that there was such a thing a Cow Magnets? They are rod shaped with smooth ends and designed for cows to swallow. Cows can eat all sorts of things on a farm that can give it grief- nails, staples, wire. Shouls this happen, a cow can loose her appetite and decrease production because of this. Cow magnets prevent this by attracting stray metal. One magnet lasts a life time- and even here in NZ! No bull!

Actually, it's magnets a bit like this that get swiped over an Argo to get them going (so I guess there's the link to Niwa)