Need to avoid the pigs from being able climb in the feed and water troughs really, they only contaminate the feeds and water, same a floor feeding, Tyre Trugs make some amazing recycled products, available from most merchants, we have used them for years and there easy to clean, just a quick jet wash. Galvinsed feeders are good too, we have a few, but their expensive and the pigs really enjoy breaking them where as the rubber ones take a good hit and are still good go!