Annual methane emissions profile for sheep grazing pasture in southern Western Australia

Document Type

Conference Proceeding

Publication Date

7-2026

Conference Title

Transforming Animal Management through Sustainable Innovations: Proceedings of the 36th Biennial Conference of the Australian Association of Animal Sciences

Place of Publication

Adelaide

Keywords

Methane Emissions, Carbon Abatement

Disciplines

Environmental Indicators and Impact Assessment | Environmental Monitoring | Sheep and Goat Science

Abstract

Enteric methane (CH4) from livestock rumen fermentation is a critical global agricultural greenhouse gas (GHG) source, accounting for approximately 80% of Australian agricultural emissions (Hegarty & Kennedy, 2011). Developing scalable mitigation strategies whether nutritional, genetic, or management based require robust baseline data for accurate national carbon accounting. However, quantifying emissions in free range grazing systems is challenging due to high seasonal variability in forage quality and composition, which significantly alters rumen fermentation pathways (e.g., volatile fatty acid ratio) and makes static pen feeding models inadequate. This study aimed to address this knowledge gap by establishing a continuous, year round CH4 emission profile for Merino sheep under dynamic grazing conditions typical of Southern Western Australia (WA) using non-invasive GreenFeed (GF) technology. Specifically, we aimed to 1) quantify individual daily CH4 emissions across distinct seasonal phases, 2) relate emission rates to changes in pasture type, and 3) generate a robust, region specific dataset to inform future mitigation research and enhance carbon accounting frameworks.

Link to Full Text

Share

COinS