Subacute ruminal acidosis (SARA) is common in high-producing dairy and feedlot cattle fed rapidly fermentable diets. It causes chronic discomfort, lameness, and secondary health problems that are largely preventable through dietary management.
SARA causes chronic discomfort that is difficult to detect because affected cattle do not show dramatic acute illness — instead experiencing a prolonged period of subclinical suffering expressed as reduced feed intake, digestive disturbance, and the downstream welfare consequences of laminitis. Laminitis from SARA is particularly welfare-significant: hoof lesions cause persistent, severe pain that impairs a cow's ability to compete for feed, walk to water, and express normal social behaviour. The preventability of SARA through sound nutritional management makes its occurrence a welfare failure — one that is also economically costly. Herd-level monitoring of milk fat depression, faecal consistency, and lameness prevalence provides early warning of SARA problems amenable to dietary correction.