Can anyone give me some advice about vitamin supplements? My chickens seem to have a vitamin A deficiency, which I'm told is quite common on the East Coast. A vet told me to give them avian vitamins, which I can find at a pet store. The only pet store around sells vitamins designed for small pet birds and the containers, which are rather expensive, have a fraction of what I would need for my chickens. The feed store sells a vitamin-electrolyte powder to add to water that is labelled "for all animal classes," and lists chickens among the animals for which it is appropriate. Is it ok to use the feed-store powder? Or do the chickens need something designed specicially for birds? If so, where can I find it? Thanks!