Rumen acidosis is not related to urine pH. Do not confuse the process of feeding anionic salts to alter calcium metabolism by inducing a slight metabolic acidosis. With anionic salt feeding, we can use urine pH as a monitor of the acidifying effect. With ruminal acidosis, the absorbed volatile fatty acids (VFA) generated in the rumen are buffered in the blood and the acid load is reduced through respiratory compensation, not urinary. Potentially in a serious ruminal acidosis situation, one might see a reduction in urine pH, but this is not a viable diagnostic tool for ruminal acidosis.
Mike Hutjens,Extension Dairy Specialist, University of Illinois - Illini DairyNET
Robert Van Saun, Extension Veterinarian, Penn State University
