Utilizing Innovative Technology to Determine Cattle Emissions
Cattle are a major source of emissions in Alberta and worldwide, producing what is known as “enteric” methane. In Alberta, they’re responsible for about half of all agricultural emissions, or four per cent of all GHGs in the province.
This project was completed in 2017 and used gas-sensor technology and other techniques to measure methane emissions from beef cattle. Funded through the Biological Greenhouse Gas (GHG) Management Program in 2014, the project used non-invasive techniques to accurately measure the methane mitigation potential of low residual feed intake (RFI) herds in real-world settings without disrupting the animals’ feed intake and feeding behaviour.
In a simulation study, researchers reported that after 25 years of selection for low RFI, GHG emissions would be 0.844 tonnes per cow per year lower compared with the average herd, or 1.64 million tonnes per year lower for Alberta’s roughly 2 million beef cows and bred heifers. The potential improvement is dramatic, but to confirm these model estimates, rigorous emission measurements were needed in real-world beef production conditions. Given this, the researchers assessed the GreenFeed Emissions Monitoring (GEM) system and Fourier-Transform Infrared Spectroscopy (FTIR) sensors for their ability to accurately measure enteric methane emissions under farm grazing and wintering conditions. GEM is an automated, individual animal feeding or “bait” station that measures carbon dioxide and methane over three to five minutes, four to five times per day over many days. Using those technologies, the researchers compared feed intake, methane and carbon dioxide emissions from high and low RFI beef heifers and cows under real-world grazing and winter feedlot conditions. Compared to other emission measurement tools such as respiratory chambers, GEM was found to be a less invasive, less expensive, less labor intensive and more accurate method.
Low RFI Cattle Confirmed as a GHG Reduction Strategy
After full selection of a beef cattle herd for RFI, researchers determined that the GHG intensity from beef production were approximately 14 per cent lower than for the non-selected baseline herd. Additionally, due to the lower feed intake of the RFI herd, the farm area required for grazing and feed production was 13.2 per cent lower than for the baseline herd, thus improving overall herd management efficiency and enabling further GHG and environmental benefits. These findings verified the selection of low RFI as a GHG reduction strategy. Additionally, the GEM system functioned well in outdoor feedlot environments through four Alberta winters where nighttime temperatures often dropped below -30 degrees Celsius. The researchers also determined that averaging over seven to 14 days with a minimum of 20 spot samples was sufficient to produce repeatable and reliable averaged methane and carbon dioxide emissions, which may be useful as best practice for similar experiments in the future.
What’s next?
RFI is still being explored and has potential in the cattle industry; however, there are certain challenges such as difficulty measuring feed intake. The next steps for this research include using the large phenotype-genotype database from this project to identify genomic biomarkers for low methane emitters. Future projects and research on RFI and adapting to climate change should be explored to enhance the research performed in this project. Since the project’s completion, the proponent continued his research in RFI with other projects out of the University of Alberta.