One of the most common methods used to detect SARA (sub-acute rumen acidosis) is the measurement of rumen pH. Traditionally this is performed using invasive techniques which involve directly taking a sample of rumen liquid. Not only can this process be disruptive and distressing for the cow, its accuracy has also been disputed as these samples cannot represent the fluctuations and changes in pH seen during SARA. However, the eCow bolus continually monitors the reticulum pH and so provides a greater insight into pH variations.

This has been evaluated in a recent study by Viktoria Neubauer, at the University of Veterinary Medicine, Vienna. She compared the use of eCow boluses with traditional methods of pH measurement and explored their potential as a diagnostic tool for SARA. As the eCow bolus measures pH in the reticulum whereas traditional methods measure the rumen, a different part of the stomach, the pH measured in these areas varies. This means that the pH threshold value, used to determine the SARA risk, also varies and so this study aimed to explore these differences.

“Daily pH variations emphasize the need of constant monitoring of ruminal pH to identify cows with SARA”


By challenging a group of dairy cows to a range of different diets the research aimed to increase the risk of SARA. They then used both traditional sampling methods, and continued sampling with the eCow bolus to characterise the pH variations associated with these dietary changes. Their results showed the that the SARA threshold for the reticulum is around pH 6, slightly higher than the rumen value of pH 5.8. Interestingly, they also noted that concentrate-rich diets increased the daily pH variation in both the reticulum and rumen, but that this was not very well characterised by traditional methods compared to the eCow bolus. This suggests the importance of continual pH monitoring when understanding rumen dynamics and diagnosing SARA.

This study has highlighted the strength of the eCow bolus in detecting SARA by continually monitoring pH changes, compared to traditional methods which only capture a snapshot of this complex system.

For more information about how our eCow boluses and newly launched Vetpack (shown right) can aid SARA detection, please visit our information pages here, or contact us directly. To read the full paper discussed in this post, please visit our recent publications page.