Evaluation of the ruminal function of Belgian dairy cows suspected of subacute ruminal acidosis.

Subacute ruminal acidosis (SARA) has been considered a major pathology in high producing
dairy herds for years. These findings were corroborated by several studies in Europe. However,
different feeding practices and herds’ production levels are found in Southern Belgium. This study
aimed to ascertain whether dairy cows of several herds from the south of Belgium (Wallonia) with
a suspicion of SARA really did present too low ruminal pH values. Twenty-four herds were visited
and 172 cows were sampled using an oropharyngeal device to collect ruminal fluid, i.e. Geishauser
probe. On the samples, three tests were performed: pH measurement, methylene blue reduction
test and microscopic evaluation of protozoa vitality. Based on these analyses, no cows demonstrated
pH values lower than 5.5 and, only ten cows could be considered at risk for SARA. By contrast, in
eightteen cows, pH values higher than 7.0 were measured and ruminal inactivity was suspected. In
this study, ruminal alkalosis appeared to be more frequently observed than SARA.