Picked up a few bags of pig nuts today for our 3 month old weaners. They were not our normal Supabreed nuts, but a "general feed for pigs". At home I noticed on the feint paper label that they are copper free. I thought copper as well as iron was essential for blood formation in piglets and these weaners were on 16% copper previously. As outdoor pigs they can get iron from the soil but copper ? Weaners are OSB's so not fast growing compared to commercial pigs. We've always used bought in feed in the past as presumably their necessary trace elements are included. Do I need to add a copper supplement or return the feed ?