A team at Tehran University (Nasrollahi,  Zali, Ghorbani,  Sharbabak and Abadi) conducted a long term study using eBolus (farmBolus for research) to look at the variability of susceptibility of cows to SARA and found interesting differences between cows on sorting behaviour, DMI and Milk Fat percentage.  They also used Rumenocentesis and compared the values and found a 0.28 pH lower difference between it and ruminal cannula. They found the eBolus accurate and we can quote them:-

“To monitor rumen pH continuously during the final period, 14 cows of the same period were fitted with indwelling wireless pH transmitting units (eBolus, eCow Ltd., Exeter, Devon, UK). This model of indwelling pH transmitter was validated through 35 d of placement without significant pH drift ….. Furthermore, this validated, wireless, telemetry device was recently used to measure reticular pH for 10 weeks and compared with measurements of rumen pH by the LRCpH system; the two systems detected a stable difference of 0.24 ± 0.08 pH units through 10 weeks (Falk et al., 2016), which we consider as additional evidence that our eBolus system could be used reliably in the present study. The eBolus is 115 mm long, has a diameter of 27 mm, and weighs 200 g (Mottram et al., 2013). Each unit was factory calibrated at pH 4.0 and pH 7.0. The eBolus reported pH and temperature every 15 min, so both pH and temperature data were S.M. Nasrollahi et al. Animal Feed Science and Technology 228 (2017) 72–82 74 collected using an analog-to-digital converter and stored in an external memory chip. These measurements were taken continuously during the final 5 d of study. The pH data were analyzed as daily mean pH, time (min/d) and area (pH × min/d) below specific cut off points (5.8 and 6.0) as well as acidosis index (area under pH 5.8 divided by kg of DMI; Penner et al., 2009). Because wireless sensors were located in the ventral reticulorumen, the term reticuloruminal pH is used to describe these data.”

This is a great result and shows the benefits of working with the eCow to ensure you get accurate rumen data for the long term in experiments and veterinary interventions.  The full text of the paper is at http://dx.doi.org/10.1016/j.anifeedsci.2017.03.007

Our only comment is that it is great to see the bolus being used so effectively and the daily range and pH change can also be indicative of nutritional problems.  We belief that rumenocentesis has limited value in comparison to our system and is damaging to the cow.