Use a granulated form of the drug Do not let market animals have access to manure from treated pigs. Drug testing kits are available. If in doubt purchase and use them. However, results on their effectiveness are mixed in scientific trials conducted thus far. As with probiotics, effect appear highly variable.
Some studies show no benefits.
The best example of a feed enzyme is Phytase . Most of phosphorus in plants and feed materials is not available for digestion and absorption. Rather it is bound in a compound called phytic acid. Phytase is a bacterial enzyme that can breakdown phytic acid, thus leading to better phosphorus digestion and thereby reducing the amount of phosphorus required in feed. Additionally, this will lead to less output of phosphorus in the manure.