B.PAS.0012 - A review of anti-methanogenic pastures and forages
Some pasture species reduce methane production in the rumen, and they could reduce GHG emissions from the red meat industry.
| Project start date: | 04 February 2025 |
| Project end date: | 06 December 2025 |
| Publication date: | 19 December 2025 |
| Project status: | Completed |
| Livestock species: | Grain-fed Cattle, Grass-fed Cattle, Sheep, Goat, Lamb |
| Relevant regions: | National |
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Summary
This report reviewed the potential of pasture species to reduce methane from ruminants, evaluated the adoptability of the most promising low methane emissions pasture species, and forecast the likely changes to red meat sector GHG emissions using a simple production and adoption model. Seven prospective species to reduce grazing emissions were chosen and evaluated: lucerne, brassicas, plantain, Leucaena, Stylosanthes, Desmanthus, and biserrula.
Objectives
The specified project objectives were to:
• Review literature on the technical potential of low emissions plants for inclusion in Australian grazing systems, including agronomic potential, national and regional impact on reducing emissions and identifying research gaps and opportunities.
• Assess the adoptability of low emissions plants in Australian grazing systems, including the stock numbers affected and adoption potential for different pasture applications.
• Assess the potential for methane avoidance programs through voluntary and government programs.
Key findings
• While there is a large amount of published literature on low emissions forages, understanding the antimethanogenic effects under commercial farm conditions is difficult as most data were collected under laboratory or experimental farm conditions. There is a lack of on-farm data.
• While there is a wide range of plant species that have antimethanogenic activity, only seven forages were considered to have a meaningful influence on methane emissions from grazing animals.
• The reduction in methane yield (g/kg DM intake) from diets with the seven forages varied between 0 and 25%.
• The combined influence of the seven prospective species increased animal productivity by 7% but reduced overall methane emissions by 3% and associated methane intensity (methane per unit of animal product) by 9%.
• The animal performance benefit of the seven species is the main driver for adoption by producers.
• Lower emissions intensity (i.e. emissions per unit of red meat produced) is an important consideration for the Australian red meat sector which exports much product globally.
• The opportunity for developing a method under the Australian Carbon Credit Unit (ACCU) scheme is very low, due to high complexity and low financial returns.
• The opportunity for incorporating low emissions species into grazing systems to increase animal productivity and improve the carbon balance on farm is high, through carbon farming initiatives.
• If performance of livestock on pasture is to be improved, it should be done using regionally adapted low emissions species.
Benefits to industry
• The review provides realistic, unbiased information on the potential for reducing methane emissions from grazing animals.
• It provides information on the limited options for seeking revenue from avoided emissions through voluntary and government schemes.
• Enteric methane is a major source of greenhouse gases, contributing about 75% of all agricultural sources. Therefore, the industry should pursue avenues to reduce emissions.
• With 95% of total red meat sector methane emitted from pasture-fed animals, even relatively small reductions could have a noticeable impact if applied at scale across grazing systems.
• While the financial incentive for reducing emissions is unlikely to be significant or even possible, the societal benefit is significant.
• Added to this the producer realises increases in livestock production and financial returns from establishment of higher yielding and higher quality pasture species.
MLA action
This report will be crucial to informing future initiatives related to the development and incorporation of antimethanogenic pastures.
Future research
• Future research should focus on integrating measurement and estimation of all carbon sources and sinks.
• Future research should focus on in vivo research with less emphasis on in vitro research because it is unlikely that further broad scale screening of species and species growth stage will reveal any prospective new species with the potential for broad impact.
• Research is needed to understand the contribution low emissions forages make to the diet of grazing animals across the year. Methods to estimate or measure the proportion of antimethanogenic species in the diet and how these influence emissions are critical.
• Pasture intake is central to methane production and an accurate and robust method for measuring or estimating intake is essential. Current methods are outdated and need revision or replacement.
• Methane measurement studies using respiration chamber methods are needed on lucerne, Desmanthus, stylos and brassicas to confirm their antimethanogenicity as current datasets are few.
• Methane measurement trials with combinations of low emissions forages as well as low emissions forages with methane mitigating additives are needed.
• Further in vivo research on select minor-use tropical legumes including calliandra, lablab and siratro to confirm limited evidence that they may reduce methane emissions
• On-farm long term monitoring to assess seasonal and management effects on methane production of grazing livestock are needed to demonstrate the reduction in methane under commercial conditions. The advent of in-field monitoring units will facilitate this research.
• Extension in promoting the dual benefits of low emissions pasture species on methane reduction and animal productivity should increase adoption rates of the prospective forages nationally. Improving animal productivity from grazing systems is an important industry goal, and widespread adoption of low emissions forages can improve both animal productivity and emissions intensity.
More information
| Project manager: | Joe Gebbels |
| Contact email: | Reports@mla.com.au |
| Primary researcher: | CSIRO |
