Reducing Methane Emissions from Cattle
Funded through Round 9: Biological Greenhouse Gas Management, this collaborative effort among researchers in Canada and Australia explored innovative dietary approaches to reduce enteric methane emissions from milk and beef cattle, while further increasing production efficiency.
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. As the demand for milk and meat products continues to rise, methane emissions from livestock production will increase further unless mitigation strategies are adopted.
Reducing methane emissions from cattle in Canada would allow ruminant systems to have an expanded role in meeting growing Canadian and global demands for livestock products. Completed in 2018, this project investigated several methane reduction technologies for dairy cows and beef cattle including diet composition and use of feed additives, with some strategies examined in combination. The estimated emission reductions for Alberta over 10 years at a 20 per cent technology adoption rate is 2.9 megatonnes of CO2e.
Developing a New Methane Inhibitor
The project involved adding an experimental methane inhibitor 3- nitrooxypropanol to cattle feed at the feedlot. Researchers found that adding this inhibitor to the cattle feed reduced methane yield of feedlot cattle by 40 per cent, without negative effects on animal productivity or carcass characteristics. Additionally, the study found that feeding wheat to dairy cows reduced methane production by 35 to 39 per cent in short-term studies, but it was not a reliable strategy for long-term mitigation of emissions. Additionally, beef cattle fed forage diets including hay and other plant material traditionally eaten by grazing livestock, had reduced emissions by 25 per cent. However, in forage-based diets fiber digestibility decreased, which may adversely affect animal productivity. During the study, researchers also found that international collaboration among scientists in Canada and Australia was a very effective approach for identifying enteric methane mitigation strategies for dairy and beef cattle production systems.
What’s next?
While short-term studies such as this project can be useful as they provide an initial screening, long-term studies are needed to show whether the reduction in methane is maintained over time. Consequently, ERA awarded a large-scale evaluation of 3- nitrooxypropanol (Demonstration of reduced enteric methane emissions in growing/finishing beef cattle through dietary supplementation of 3 Nitrooxypropanol at a commercial scale in Alberta – Emissions Reduction Alberta (eralberta.ca). The study is complete and demonstrates the day-to-day practicalities of supplying NOP as a feed ingredient in commercial backgrounding and finishing beef operations including the establishment of a Carbon Offset Protocol.