When our grey Arab stallion starts to look a bit pink in the face we know he needs his red rocky copper lick,
You can also get a 10 kilo bag of horse minerals from some agri supply places to add to hard feed.
With the block licks If you drop them in a plastic tub fixed to a top rail, and drill a hole in the bottom of it to let rain out then the sheep can't reach it when it breaks up.