Identifying Plants that Reduce Methane Production Using an In Vitro System—Helping the Challenge to Become C Neutral ^†

Abstract

The Australian red meat industry has set a goal to be carbon neutral by 2030. Reaching this goal will be a challenge and will involve targeting ways to increase carbon in the landscape, improve efficiency of production and reduce methane emissions from ruminants. There are a number of different options the industry can pursue to try and achieve its goal, including changing grazing management practices and land-use to changing the animal, what it eats and the microbial ecology in their rumen. No single one of these options will enable the red meat industry to become carbon neutral by 2030, it will take a combination of all of them to help meet the challenge. We have been using an in vitro batch fermentation system and a Rusitec system as a quick, relatively inexpensive, way to screen; plants that already exist in our grazing systems, novel plants, plant extracts and organic waste products from the horticultural industry, for their potential to improve the efficiency of fermentation and reduce methane production in the rumen. We have also used these systems to provide an initial clue about the mechanism of action at the level of the ruminal microorganisms. We have identified variation in these traits amongst the plants, plant extracts and horticultural waste products we have tested that could help develop systems that reduce the environmental footprint of ruminants in tropical production systems in Australia and in other parts of the world.