I have seen a really under weight very very very poor feeder that looked well under weight, her ribs we easy to feel and her belly was U shaped it was actually really really obvious that she was WAY under fed and the owner was going crazy with her (breeder actually, with over 200 animals and 3 real problem feeders) She is on the mend now as he passed her and the other 2 along to a friend to work closely with them to get them feeding so far capped ASFs seems to be working.