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Worldwide, there was an estimated 1.002 billion head of cattle in 2018, increasing by 6.5 million head over 2017.1 Global meat production has continued and appears to be continuing to grow. Although cattle now accounts for a comparatively smaller proportion of overall meat consumption, there were still over 68 billion tons of cattle meat produced in 2014.2 US Beef Exports alone in 2018 was worth 7.3 billion dollars3 so cattle farming continues to be a profitable business.
However, concerns about the environmental impact of cattle farming have increased. This is mainly due to cattle producing a substantial amount of methane gas of between 250 – 500 L each day.4 As a heat-trap, methane is more effective and efficient than the most prevalent greenhouse gas in the atmosphere (CO2) and is potentially a large contributor towards global warming.
As livestock is a critical source of economic and nutritional sustenance for numerous communities, it is not likely cattle farming will end in the immediate future. Therefore, discovering ways to cut methane production from cows is a vital route to enhancing the sustainability of cattle farming and limiting its environmental impact.
Reducing Methane Production in Cows
Discovering ways to cut methane production from cows is currently a highly active research area. Cows and other ruminant species produce methane as part of their digestion process. This is due to ruminants being one of the few species that can digest cellulose, which is what the cell walls in plants consists of.
Breaking down cellulose is a multi-step process, which involves regurgitation and re-ingestion of the food and the utilization of a vast array of microbes that conduct fermentation of the plant material. The fermentation process is what produces most of the methane gas, which leaves the cow through flatus or eructation.
A great deal of the research which aims to reduce methane production involves finding methods to alter the digestive process and microbes in the cow’s stomach. Some progress has been made by either modifying the composition of the ruminants’ diets, such as increasing the quantity of sugarcane feed5 or by the addition of methane-inhibiting chemicals.6
The challenge with using additives is locating non-toxic chemical species that do not have undesirable side effects on produce, whether it is the milk or meat of the animal.
However, all this research depends on being able to precisely and unobtrusively monitor methane production in cattle. Indirect calorimetry respiration chambers are frequently thought to be the ‘gold standard’ of methane measurement methods7 but entail huge capital investment and are not suitable for use with large amounts of animals. They also necessitate confinement of the animal, which may make such measurements an inaccurate reflective of normal behavior.8
As variations in methane emission from dietary changes may be minute, sensing technologies must have good sensitivity as well as accuracy and reproducibility.
Recent work has demonstrated that non-dispersive infra-red (NDIR) sensor technologies show better repeatability for methane concentration measurement and that the concentrations measured were in line with those measured by other techniques.9 NDIR sensor technologies are especially useful for methane detection. For the same reason, it is such an efficient heat trap in the atmosphere, while methane significantly absorbs infra-red light.
Edinburgh Sensors has 30 years of experience in the development of NDIR gas sensors for the monitoring of hydrocarbons and other gaseous species. Its NDIR devices have already demonstrated success in detecting methane production in cows9 in field environments with their robust design, which is easy to install and use.
The Guardian NG is an example of a methane monitor that is perfect for such applications and able to detect methane in low concentrations of 0 – 1 %.10, 11
The Guardian NG is fitted with an R323 interface with the option of TCI/IP communications protocol so it can be connected to data logging networks to observe real-time variations in methane emission levels. The sensor is also equipped with data logging software, so it only needs to connect to a PC via a cable to be able to start recording measurements immediately.12
With a robust design, the device requires minimal installation and set-up time. The zero stability has a ±2% of range (over 12 months) with an outstanding ±2% accuracy. Critical for use on live farm environments, the readouts are also temperature, humidity and pressure compensated and are still precise over 0 – 95 % humidity conditions.
Picture of a Guardian NG. Image Credit: Edinburgh Sensors
The Guardian NG only requires a connection to a reference gas for set up and, with a T90 of just 10 seconds, it has a fast response time. This is perfect for cases where samples from multiple cattle must to be processed quickly or many samples are taken each day.
The Guardian NG can be set up as an automated gas analyzer to limit the amount of personnel time involved in the monitoring. For the cattle, this monitoring is also completely non-invasive and does not necessitate attempts to take samples from them, making the Guardian NG a cost-effective and straightforward solution for methane monitoring of cattle.
References and Further Reading
- Food and Agriculture Organization (2020) http://www.fao.org, accessed 28/02/2020
- Meat Production (2020), https://ourworldindata.org/meat-production, accessed 28/02/2020
- WorldBank (2016), http://siteresources.worldbank.org/INTAFRICA/Resources/257994-1215457178567/Cattle_and_beef_profile.pdf, accessed 28/02/2020
- Johnson, K. A., & Johnson, D. E. (1995). Methane Emissions from Cattle. J. Anim. Sci., 73, 2483–2492.
- Hulshof, R. B. A., Berndt, A., Gerrits, W. J. J., Zijderveld, S. M. Van, Newbold, J. R., & Perdok, H. B. (2012). Dietary nitrate supplementation reduces methane emission in beef cattle fed. Journal of Animal Science, 90(7), 2317–2323. https://doi.org/10.2527/jas2011-4209
- Hristov, A. N., Oh, J., Giallongo, F., Frederick, T. W., Harper, M. T., Weeks, H. L., … Kindermann, M. (2015). An inhibitor persistently decreased enteric methane emission from dairy cows with no negative effect on milk production. PNAS, 112(34), 10663–10668. https://doi.org/10.1073/pnas.1504124112
- Gold - Difford, G. F., Olijhoek, D. W., Hellwing, A. L. F., Lund, P., Bjerring, M. A., de Haas, Y., … Løvendahl, P. (2018). Ranking cows’ methane emissions under commercial conditions with sniffers versus respiration chambers. Acta Agriculturae Scandinavica A: Animal Sciences, 68(1), 25–32. https://doi.org/10.1080/09064702.2019.1572784
- Grainger, C., Clarke, T., McGinn, S. M., Auldist, M. J., Beauchemin, K. a, Hannah, M. C., Waghorn, G. C., et al. (2007). Methane emissions from dairy cows measured using the sulfur hexafluoride (SF6) tracer and chamber techniques. Journal of Dairy Science 90(6), 2755–2766.
- Rey, J., Atxaerandio, R., Ruiz, R., Ugarte, E., González-Recio, O., Garcia-Rodriguez, A., & Goiri, I. (2019). Comparison between non-invasive methane measurement techniques in cattle. Animals, 9(8), 1–9. https://doi.org/10.3390/ani9080563
- OEM Sensors (2020), https://edinburghsensors.com/products/oem-co2-sensor/, accessed 28/02/2020
- Methane Sensors (2020), https://edinburghsensors.com/methane-and-carbon-dioxide-sensing-for-anaerobic-digestion-and-biogas/, accessed 28/02/2020
- Gascard NG (2020), https://edinburghsensors.com/products/gas-monitors/, accessed 28/02/2020
This information has been sourced, reviewed and adapted from materials provided by Edinburgh Sensors.
For more information on this source, please visit Edinburgh Sensors.