P.PSH.1260 - Screening feed additives for methane mitigation using in vitro studies
There are additives that can substantially reduce methane from ruminant livestock. MLA conducted some research to use laboratory techniques to do some initial screening of potential feed additives to use in CN30 research.
| Project start date: | 18 June 2020 |
| Project end date: | 15 November 2022 |
| Publication date: | 03 May 2024 |
| Project status: | Terminated |
| Livestock species: | Grain-fed Cattle, Grass-fed Cattle, Sheep, Goat, Lamb |
| Relevant regions: | National |
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Summary
Reducing enteric methane (CH4) emissions from ruminants is a key priority to improve environmental sustainability and consumer perception of Australian red meat production. This project used high throughput laboratory screening methodology to identify feed additives with potential to supress enteric CH4 production, whilst maintaining favourable ruminal digestion and fermentation. Nine additives were selected for evaluation based on previous literature. Additives, at doses recommended by manufacturers, were combined with Rhodes grass hay and subjected to a 48h batch culture incubation.
The four additives which exhibited the greatest CH4 mitigation potential included two biochar samples, Citral, and Sandalwood oil, also affected rumen fermentation parameters, to varying degrees. Citral and Sandalwood oil had detrimental effects on digestibility, which when combined with the price of these supplements made them unviable for livestock feed supplements in their current state. Detailed knowledge of biochar composition and the additional compounds it contained (KNO3 and asparagopsis), would facilitate an understanding of how these products are able to elicit changes in CH4, but were considered to have confounding effects in the current trial, with the source of the effect unknown. As such, no additives studied in this project met the criteria to be further evaluated in the RUSITEC system.
Objectives
o Determine the effect of graded levels (dose response) of provided feed additives on batch-culture fermentation utilising roughage diets.
o Based on the results of the batch culture, select the two most promising additives for screening by RUSITEC (in-vitro rumen simulation technique)
o Determine the effect of the graded levels of the two most promising additives on RUSITEC fermentation.
o Determine changes in the rumen microbial population (abundance and diversity) associated with treatment responses from RUSITEC fermentation.
Key findings
The four additives which exhibited the greatest CH4 mitigation potential included two biochar samples, Citral, and Sandalwood oil, also affected rumen fermentation parameters, to varying degrees. When combined with additional information on product availability for livestock and price, they were not considered viable options to progress to the RUSITEC evaluation.
Benefits to industry
There are multiple benefits for industry in being able to use additives to reduce livestock methane. These include potential productivity/profitability improvements, additional income through carbon markets, ability to market products as low carbon or carbon neutral.
MLA action
MLA continues to investigate and discover potential new feed additive solutions that can contribute to reducing industry methane emissions
Future research
The planned RUSITEC trials did not proceed. A thorough economic assessment of future promising additives in addition to in-vitro screening would facilitate an evaluation of the feasibility of industry adoption.
More information
| Project manager: | Margaret Jewell |
| Contact email: | reports@mla.com.au |
| Primary researcher: | University of Queensland |
