METHYLMALONIC ACID IN RUMINANT URINE - RE-EVALUATION

A comparison of two methods of measuring methylmalonic acid in urine indicated that an indirect technique overestimates that acid in ruminant urine due to the conversion of unknown compounds to propionic acid. When it was examined by mass spectrometry, the more direct technique with which it was compared also was in error because of interference from oxalic and benzoic acids. Published amounts of methylmalonic acid for normal cattle urine, and in some cases possibly also sheep urine, are too high. This raises a question whether there is currently available a method appropriate for rapid routine analysis of this acid in urine of ruminant animals. © 1979, American Dairy Science Association. All rights reserved.