Studies on the pH value of abomasal contents in dairy cows during the first 3 weeks after calving.

The pH value of the abomasal contents in adult cattle is normally constant and has a value of 2. Abomasal contents with pH values of 5.5 and higher could give rise to bacterial fermentation with subsequent gas production. The accumulation of gas is thought to form a key event in the pathogenesis of abomasal displacement. The aim of the present study was to determine the pH values of abomasal contents of dairy cows in the first 3 weeks after calving. The pH of the abomasal contents was, over several days. higher than the pH value of the abomasal juice in mid-lactation cows. The highest pH values were measured on day 14 after calving, thereafter the pH declined. Possible explanations for the rise in the pH value of the abomasal contents are discussed.