Very good point you raise there Scotsgirl
As it says on the packet suitable for adult sheep and goats, I'll be honest I never even clicked there was copper in it, but am very aware of copper poisoning having goats and sheep myself.
As far as I can see, it looks around 600mg of copper in a sachet. The toxic dose is listed as 20-100mg/kg, so the recommended dose of 1/3 sachet per adult sheep will be well under this, and I would scale it down for a lamb. Even a 10kg lamb would be fine with 1/3 sachet, but if you were to cut it down to 1/6 or even 1/4 that should be fine.
The powder has a whole bunch of nutrients which feed the rumen bacteria, and some bacteria themselves, also a bit of vitamins etc that just generally help the guts to recover themselves.
Hope that helps
Suzanne