Acidification

     Acids are sometimes added to animal feed ingredients or diets to protect the material against microbial deterioration or to reduce the pH in the animal’s stomach. Propionic acid can be added to hay or cereal grains to prevent the growth of moulds and the formation of mycotoxins. This allows such feed materials to be stored safely with a higher moisture content than is normally recommended. Short-chain organic acids (e.g. formic, propionic, fumaric and citric) can be added to diets for newly weaned piglets to reduce digestive upsets. The young piglet has an immature gut, where enzymatic activity and hydrochloric acid secretion are not sufficiently developed; piglet feeds often have a high acid-binding capacity and are fed in relatively large meals. Organic acids reduce the incidence of diarrhoea in piglets by their antimicrobial action on the feed itself, by reducing stomach pH and by acting as energy sources. Lactic acid can be added to dried milk powder for artificial rearing of calves. Lactic acid preserves reconstituted milk, allowing ad libitum feeding of cold milk; it also reduces the pH of the calf’s abomasum, thereby assisting clot formation.