New to this buy/sell calving operation and have question regarding health of calves. We purchase calves approximately 5-8 months and weighing between 200-350 lbs keep them for about six months and resell. The last two sets have became sick after purchasing and being on our place after about two weeks with flu signs, (vet diagnosed), and we lost a few last purchase because of this and I want to try to prevent future loss if possible. Do flu outbreaks spread through sell barns or is this something this age bracket has to go through? Should we be innoculating (innoculate with what) these immediately after purchase or more basically... what should the method be when purchasing feeder calves within their entire health care? We do keep them separated from other stock; keep them watered and fed within a smaller pasture allotment until they adjust to new environment. Befuddled and any help is going to be appreciated.