Diagnosis and Management of Subacute Ruminal Acidosis in Dairy Herds.

Subacute ruminal acidosis (SARA) is a common problem in lactating dairy cows that causes chronic health problems, impairs feed efficiency, and increases the environmental impact of milk production. Low ruminal pH appears to be the main instigator of the pathophysiology of SARA, although other metabolites produced in the rumen may be involved. Inflammatory responses to SARA are variable but important determinants of a cow's response to SARA. SARA can be diagnosed at the herd level by integrating information about clinical signs and on-farm measures of ruminal pH. Prevention of SARA requires excellent feeding management and proper diet formulation.