The inclusion of antibiotics, in-feed is the most common method of controlling and preventing diseases. (Fig.4-9).

In-feed medication can be an effective means of control when used over several weeks.

In-feed medication is wasteful in that it is inevitably given to healthy pigs that do not need it as well as to the diseased pigs that do need it. In-feed supplements can also be used as top dressings, that is, sprinkling small amounts over the feed to administer the antibiotic. Top dressing is a very suitable method for small groups of pigs and individually fed animals, such as sows and boars.