Designed for research, applied to farms

The eBolus is a wireless telemetric device swallowed by the cow that provides continuous and accurate measurements of pH, temperature and reduction potential inside the reticulum. It is used to validate and control risks when changing diets in high yielding dairy cows.

When properly used, the data from the bolus can be used to optimise feeds and increase yields, thereby decreasing feed costs.

The rumen and pH and temperature levels are:

  • Recorded every minute

  • Averaged and sent every 15 minutes to the Base Station via LoRa (low range radio technology)

  • Continuously stored on the bolus if the animals are within range (200-500m)

  • Sent and backdated when the animal returns in the signal range

  • Accessible as graphs and raw data in .csv format

The Bolus is a product developed after more than 15 years of experience in designing and making pH telemetry boluses for research scientists around the world.

pH measurements

The graph below shows the pH variation over a 3 month period, with the red line showing the threshold for acidosis. Towards the beginning of this period the cow shows signs of being at risk of acidosis. This is easily recognisable and afterwards, the pH quickly rises to a safe level. Our system is also highly accurate allowing you to detect SARA and other conditions very easily.


Screenshot 2021-08-31 at 15.40.50.png

Temperature measurements

  • Used to monitor drinking activity: cold water correlates with a sharp but brief drop in the rumen temperature

  • These changes are not changes in the overall body temperature of the cow

  • Changes in the average (mean) daily temperature of the cow’s rumen can be linked to an overall change in the body temperature of the cow - as the rumen is consistently 1°C above the rest of the body.

  • Peaks in temperature are often observed when a cow is suffering from an infection such as mastitis.

  • Infections such as mastitis or SARA may also be observed as a lack of drinks taken and a drop in ruminal pH.

Screenshot 2021-08-31 at 15.40.07.png


Toby Mottram, the inventor of our bolus technology, has written over 50 scientific publications about many aspects of improving dairy cow management.

You can find most of them on ResearchGate or below. Some papers are behind payment barriers.

Recent Conference Papers about rumen pH

Kröger I., Neubauer V., Humer E., Reisinger N., Zebeli Q., Relationship between continuously measured reticuloruminal pH and chews per bolus, milk fat, milk protein and fecal pH in dairy cows. 101– 21st European Society of Veterinary and Comparative Nutrition Congress. Cirencester, United Kingdom (September 20-23rd 2017)

Mottram T. T., 2016, Detecting sensor drift in rumen pH data. 1st International Conference on Precision Dairy Farming. Leeuwarden, The Netherlands (21st-23rd June 2016)

Mottram T. T., 2016, Is monitoring rumen pH a routine tool or a seasonal adjustment to new forage quality?

Proceedings of the 7th Nordic Feed Science Conference, Uppsala, Sweden 14-15th June 2016. Presentation: Presenting eCow FSC Full Text: Is monitoring rumen pH a diagnostic or routine tool

Mottram T. T., 2015, The effect of husbandry system on rumen pH in dairy cows. Proceedings of 66th Conference of the EAAP, Warsaw; 09/2015. Presentation: Effect of husbandry system on rumen pH

Mottram T.T, Jeremy Hamilton, Richard Cooper, 2014, Measuring rumen pH on farms with wireless telemetry boluses shows the impact of farm routine. British Cattle Veterinary Association Congress, Hinckley Island, Leicestershire; 10/2014 Presentation: BCVA TM 181014

Mottram T.T., 2014, Dairy farm evaluation of rumen pH bolus data: identifying the benefits, case studies of rumen pH, 65th EAAP conference Bratislava, Abstract no. 18716. Paper: EAAP2014 18716 Case Studies in Rumen pH

Book Chapters

Toby Mottram: Animal Interactions with their Environment: Dairy Cows in Intensive Systems. Quantitative Aspects of Ruminant Digestion and Metabolism, 2nd edited by J. Dijkstra, J.M.Forbes, J.France, 01/2005: chapter 25: pages 663-680; CABI Publishing., ISBN: 0-85199-814-3


A. Bach, I. Guasch, G. Elcoso, J. Duclos, H. Khelil-Arfa: Modulation of rumen pH by sodium bicarbonate and a blend of different sources of magnesium oxide in lactating dairy cows submitted to a concentrate challenge (2018) Journal of Dairy Science, In press,

R. E. Coon, T. F. Duffield, T. J. DeVires: Effect of straw particle size on the behaviour, health, and production of early-lactation dairy cows (2018) Journal of Dairy Science, 101(7): 6375-6387,

I.Kröger, E.Humer, V.Neubauer, N.Reisinger, S.Aditya, Q.Zebeli: Modulation of chewing behaviour and reticular pH in nonlactating cows challenged with concentrate-rich diets supplemented with phytogenic compounds and autolyzed yeast (2017) Journal of Dairy Science, 100(12): 9702-9714,

O. Hanušovský, D. Bíro, M. Šimko, B. Gálik, M. Juráček, M. Rolinec, L. Balušíková: The dynamics of the ruminal content pH chnage and its relationship to milk composition (2018) Acta Vet. Biro, 87: 119-126,

V. Neubauer, E. Humer, I. Kröger, T. Braid, M. Wagner, and Q. Zebeli: Differences between pH of indwelling sensors and the pH of fluid and solid phase in the rumen of dairy cows fed varying concentrate levels (2017) Journal of Animal Physiology and Animal Nutrition: Short Communication, DOI: 10.1111/jpn.12675

C. Villot, B. Meunier, J. Bodin, C. Martin, and M. Silberberg: Relative reticulo-rumen pH indicators for subacute ruminal acidosis detection in dairy cows (2017) Animal, First View, DOI:10.1017/S1751731117001677

C. Villot, C. Martin, B. Meunier, MM. Mialon, M. Silberberg: Relative rumen pH thresholds to predict subacute ruminal acidosis (SARA) in dairy cows. EcPLf Annual Conference, Nantes, France; 11/2017

Ondrej Hanušovský, Daniel Bíro, Milan Šimko, Branislav Gálik, Miroslav Juráček, Michal Rolinec, Róbert Herkeľ: Drinking regime evaluation with continuous ruminal monitoring boluses (2017) Acta fytotechn zootechn, 20: 1–5

S. M. Nasrollahi, A. Zali, G. R. Ghorbani, M. Moradi Shahrbabak, M. Heydari Soltan Abadi: Variability in susceptibility to acidosis among high producing mid-lactation dairy cows is associated with rumen pH, fermentation, feed intake, sorting activity, and milk fat percentage (2017) Animal Feed Science and Technology, 228: 72-82,

I. Kröger, V. Neubauer, E. Humer, P. Ertl, N. Reisinger, P. Pourazad, S. Aditya and Q. Zebeli: Supplementation of feed additives to a concentrate-rich diet modulates chewing activity and ruminal pH in Holstein cows (2016) ESVCN Annual Conference, Berlin, Germany; 09/2016

Gerardo Caja, Andreia Castro-Costa and Christopher H. Knight: Engineering to support wellbeing of dairy animals (2016) Journal of Dairy Research, 83:136-147, doi:10.1017/S0022029916000261

Ondrej Hanušovský, Daniel Bíro, Milan Šimko, Branislav Gálik, Miroslav Juráček, Michal Rolinec, Marián Majlát, Róbert Herkeľ: Continual monitoring of reticulorumenal pH of dairy cows during 45 days (2015) Acta fytotechn. zootechn., 18, 2015(3): 53–55

Toby Mottram: Survey of rumen pH in commercial dairy herds. EAAP Annual Conference, Warsaw, Poland; 08/2015.

Toby Mottram, Jeremy Hamilton, Richard Cooper, Daniel Daly: Measuring rumen pH on farms with wireless telemetry boluses shows the impact of farm routine. British Cattle Veterinary Association Congress, Hinckley Island, Leicestershire; 10/2014

Toby Mottram: Dairy farm evolution of rumen pH bolus data identifying the benefits. EAAP Annual Conference, Copenhagen, Denmark; 08/2014. Abstract no. 18716

Arnaud Nogues: Commercial Benefits of Routine Monitoring of Rumen pH in Dairy Cows in South West England. 2013

T. T. Mottram, J. McCubbine, S. B. Nimmo: A novel method of calculating a SARA index by wireless rumen pH telemetry. 2013

Martinez-Ortiz, Carlos A. Everson, Richard M. Mottram, Toby: Video tracking of dairy cows for assessing mobility scores. Joint European Conference on Precision Livestock Farming, 10 – 12 September 2013, Leuven, Belgium.

Toby Mottram: Wireless technologies for monitoring grazing animals. Profitable and Sustainable Grazing Systems – Moving Forward with Science; 02/2013.

T. T. Mottram, J. McCubbine: Towards routine monitoring of rumen pH temperature and redox in ruminants. 2013

Toby Mottram: Investigating the suitability of electronic identification in livestock. 09/2011; 169(10):247-8. DOI:10.1136/vr.d5466

Toby Mottram, Nick J. Bell: A Novel Method of Monitoring Mobility of Dairy Cows. First North Am. Conf. Precision Dairy Management, Toronto; 10/2010

Phillips, T. Mottram, D. Poppi, D. Mayer, M R McGowan: Continuous monitoring of ruminal pH using wireless telemetry. Animal Production Science 01/2010; DOI:10.1071/AN09027

Toby T Mottram: Is A Lifetime Rumen Monitoring Bolus Possible? The First North American Conference on Precision Dairy Management 2010

Toby Mottram, John Lowe, Michael McGowan, Nancy Phillips: Technical note: A wireless telemetric method of monitoring clinical acidosis in dairy cows. Computers and Electronics in Agriculture 11/2008; 64(1-64):45-48. DOI:10.1016/j.compag.2008.05.015

Drysdale T D, Mottram T T and Cumming D R S, 2008 WSN Modelling the Attenuation of Radio Signals by Bovines, Proceedings of the American Society of Agricultural and Biological Engineers, Paper number 084589, 2008 Providence, Rhode Island, June 29- July 2, 2008.

Kwong K H, Goh H G, Michie C, Andonovic I, Stephen B, Mottram T and Ross D: Wireless Sensor Networks for Beef and Dairy Herd Management. 2008 Rhode Island, ASABE Meeting Presentation, paper number: 084587

Toby Mottram, Alisa Rudnitskaya, Andrey Legin, Julie L Fitzpatrick, P David Eckersall: Evaluation of a novel chemical sensor system to detect clinical mastitis in bovine milk. Biosensors & Bioelectronics 06/2007; 22(11):2689-93. DOI:10.1016/j.bios.2006.11.006

CP Schofield, RD Tillett, NJB McFarlane, TT Mottram, AR Frost, S. Cox: Emerging technology for assessing the composition of livestock. Proceedings of the second European conference on precision livestock farming, 2ECPLF 2005, Uppsala, Sweden, 9-12 June 2005; 01/2005

G. Caplen, T. T. Mottram, A. R. Pickard, S. R. Milligan: A Biosensor‐Based Method for Non‐invasively Monitoring Wildlife Reproduction—The Field Vole (Microtus agrestis) as a Potential Biomarker of Environmental Disruption. Analytical Letters 12/2004; 37(8):1719-1735. DOI:10.1081/AL-120037598

Velasco-Garcia, M. N., Mottram, T. T. (2002) Biosensors Technology and Opportunities in Livestock Production. Landwards 57 (2), Information Engineering for Agriculture and Horticulture, pub. SRI 15th May 2001, 16-20.

T. Mottram, G. Caplen, A. Pickard, S. Milligan: Monitoring wild fauna non invasively. 2001 ASAE Annual International Meeting

Maria N Velasco-Garcia, Toby Mottram: Biosensors in the livestock industry: an automated ovulation prediction system for dairy cows. Trends in Biotechnology 12/2001; 19(11):433-4. DOI:10.1016/S0167-7799(01)01841-8

R J Dewhurst, R T Evans, T T Mottram, P Spanĕl, D Smith: Assessment of rumen processes by selected ion-flow-tube mass spectrometric analysis of rumen gases. Journal of Dairy Science 07/2001; 84(6):1438-44. DOI:10.3168/jds.S0022-0302(01)70176-2

T. Mottram, W. Ditcham, A. Al Obaidi and D. McStay: The role of biosensors in sensor development strategy for the dairy industry. Silsoe Research Institute, 1998.

Toby Mottram: Automatic monitoring of the health and metabolic status of dairy cows. Livestock Production Science 06/1997; DOI:10.1016/S0301-6226(97)00029-8