Current research programme

The NZAGRC-PGgRc methane research programme builds on the NZAGRC's 2010-2013 methane science objectives and the PGgRc's methane work programme from 2007-2013.

The NZAGRC-PGgRc methane research programme pools New Zealand's resources to identify the most effective and practical solutions for reducing methane in New Zealand's agricultural industry.

Our research programme aim is to deliver efficient, cost effective, highly productive, on-farm solutions to ensure New Zealand agriculture is economically and environmentally sustainable through the reduction of agricultural greenhouse gas emissions.

The 'Mitigating Methane Emissions' research programme has four main aims for delivery in the next one to three years:

There is also a feasibility study being undertaken to understand the potential to capture and convert methane in soil and a validation trial of a rapid, low cost system for measuring methane.

Research Principal Investigators

Dr Graeme Attwood, AgResearch
Dr Peter Janssen, AgResearch

Research Stories

  • Decreasing methane emissions by feeding grazing ruminants: a fit with productive and financial realities?

    Pacheco, D., G. Waghorn, et al. (2014). "Decreasing methane emissions from ruminants grazing forages: a fit with productive and financial realities?" Animal Production Science 54(9): 1141-1154.

    Ruminants contribute to human food supply and also anthropogenic greenhouse gas (GHG) emissions. An understanding of production systems and information on animal populations has enabled global inventories of ruminant GHG emissions (methane and nitrous oxide), and dietary strategies are being developed to reduce GHG emissions from ruminants. Mitigation strategies need to consider the management/feeding systems used to ensure that these strategies will be readily accepted and adopted by farmers. Housed systems allow diets to be formulated in ways that may reduce GHG production, but the challenge is much greater for systems where animals graze outdoors for long periods. A methane mitigation option in the form of fresh forage would be desirable in livestock production systems with high reliance on grazing. A brief summary of New Zealand research, carried out on fresh grasses, legumes, herbs and crops, suggest that we have an incomplete understanding of the feed characteristics that define a ‘high’ or a ‘low’ methane feed. The variation in methane emissions measured between feeds, individual animals and experiment is large, even in controlled conditions, and the dynamic nature of sward-animal interactions will only exacerbate this variation, creating challenges beyond the identification of mitigants. Furthermore, implementation of knowledge gained from controlled studies requires validation under grazing systems to identify any trade-offs between methane reduction and animal productivity or emission of other pollutants. Therefore, investment and research should be targeted at mitigation options that can and will be adopted on-farm, and the characteristics of temperate grasslands farming suggest that these options may differ from those for intensive (high input/output) or extensive (low input/output) systems.

  • Dr Peter Janssen, Principal Investigator

    Dr Peter Janssen is the Principal Investigator of the PGgRc-NZAGRC methane mitigation programme at AgResearch, and co-ordinates and contributes to the different work streams developing technologies to reduce ruminant methane emissions. He has established methods for investigating the microbial ecology of the rumen ecosystem, and for isolating novel rumen microbes.

    Peter has been involved in several global projects to increase knowledge of the rumen, most notably co-leading the Global Rumen Census project.

    Peter is an internationally recognised expert in isolating so-called unculturable microbes.

    Prior to joining AgResearch, he was an Associate Professor and Reader at  the University of Melbourne, where his research team made recognised advances in solving the “Great Plate Count Anomaly”.

  • NZAGRC welcomes PCE report on agricultural GHG mitigation

    Wednesday, 19 October 2016
    The Parliamentary Commissioner for the Environment’s report into greenhouse gas emissions from agriculture highlights the need for a suite of mitigation solutions rather than a single silver bullet.

    The PCE report is available at 

  • Global solutions to reduce methane emissions from ruminant animals are feasible, because the microbes causing the emissions are similar around the world

    The New Zealand-led “Global Rumen Census” project analysed the microbes responsible for ethane emissions from a wide range of ruminant animals around the world. The project found imilar bacteria and methanogens dominate in nearly all rumens across a wide variety of species and animal diets. This means that new technologies that seek to reduce methane emissions by influencing rumen microbes should have global applications.

    The results of the Global Rumen Census were released on 9 October 2015 in the open-access journal Scientific Reports.

    Global press release

    pdf GRC Global Release (0.31MB) 

    New Zealand press release

    pdf GRC New Zealand Release (0.34MB) 

    Science Q&A

    pdf GRC Q&A (0.29MB) 

    Rumen microbial community composition varies with diet and host, but a core microbiome is found across a wide geographical range
    G. Henderson, F. Cox, S. Ganesh, A. Jonker, W. Young, P.H. Janssen. 2015.
    Scientific Reports 5: 14567.

  • Co-leader of breeding programme keen to make a positive contribution to farming

    Dr Suzanne Rowe, co-leader of the NZAGRC-PGgRc programme to breed low methane ruminants, has always been passionate about farming. Originally from Devon, in the UK, she grew up in the city and left home at 16 to work on a horse breeding stud. Suzanne then moved on to milking cows, which she enjoyed for many years. She found herself milking for a progressive farmer, Herbert Mitchell, who, with his son, was breeding dairy cows for production with a huge emphasis on recording. Tregear farm had been in the family for more than 100 years and the 150 cows were averaging about 10,000 litres of milk. “In terms of production index, at one point it was second only to Scotland’s Rural College research farm, which is an outstanding achievement for a small family farm”, Suzanne remembers.


    Tregear was a great place to learn and it was here that Suzanne became interested in making a difference to the agricultural sector. In between milkings, she studied for her A-levels and then attended agricultural college, continuing to milk at weekends and at any other occasional opportunity that she could. From there, she moved to Edinburgh to study quantitative genetics and genomics at the University of Edinburgh. “With my fascination with breeding, it really was the best place in the world that I could have studied”, she reflects. In the second year of her degree, Suzanne was required to spend a year working on a farm. Given she had spent so much time milking cows in the UK, she did not think it made sense to stay there. There was a job advertised on an African farm and, despite a warning from the careers advisor at the University who said it was too dangerous, she decided to take it. She and her husband Tim worked as a team on the remote property in Kalomo, southern Zambia, with Suzanne running the dairy and her husband running the workshop. She hand-milked cows, made butter and cheese, and they grew cash crops such as maize and tobacco. There was a mix of Zebu and Friesian cattle on the property. “The Friesians were great for milk but their tick resistance was extremely low. A massive amount of work went into just keeping them alive”, Suzanne says. “It was a fantastic experience which taught me a lot about agriculture because it was so basic compared with what I’d learnt at home”.


    Suzanne completed her masters degree, followed by a PhD in quantitative genetics, and then stayed for some post-doctoral work. Always a firm believer that, in science, you should not stay in one group for an entire career, Suzanne decided that the next move that she made would be a big one. With that in mind, the Rowe family moved to Otago two years ago. One of the biggest attractions was the strong team at AgResearch’s Invermay campus, with the likes of Dr John McEwan, who is world-renowned in genomics, and Dr Ken Dodds. Suzanne was also attracted to New Zealand by the value and importance of agriculture to our economy.


    In addition to working on the NZAGRC-PGgRc breeding programme, Suzanne has also found time to work on the development of genomic tools for the deer industry and genetic mapping of genes associated with disease and production traits in sheep. She has also been looking at gene by environment interactions in the New Zealand sheep flock and is interested in the development of a dairy sheep industry in New Zealand. “I’m never bored. There’s plenty to do here,” Suzanne told us. “I’m really enjoying working at Invermay. It’s pretty unique to get this level of expertise in all these different areas in one place. I feel that I’m putting my skills to great use here and I’m positive about making a real contribution to the future of NZ agriculture”.

  • 1115 Rick Pridmore, Strategy and Investment Leader for Sustainability (DairyNZ)

    Rick provided the conference delegates with an overview of the New Zealand investment landscape for reducing agricultural greenhouse gases.

    He highlighted that New Zealand is putting in a great deal of effort into reducing agricultural greenhouse gas emissions and conducting top class science, which in many areas is nearing proof of concept.

    Rick also emphasised that there are a significant number of funders in this area covering government, industry, the universities and CRIs.

    At the research end, the plans and investment are fairly coordinated, mainly due to the actions of the NZAGRC and PGgRc, however at the applied end there is room for improvement. This is primarily due to the fact that there are many issues to be considered on-farm and greenhouse gas emissions are just one of the factors in the mix.

    New Zealand farm greenhouse gas emissions intensity has been decreasing at approximately 1% per year due to increased efficiency and the goal is to keep this rate going into the future, but on top of that, reduce emissions intensity by a further 1.5% per year by additional technological options. This 1.5% may be achieved by step changes between 2020 and 2050, rather than a gradual decline.

    Rick outlined the four key research aims of the NZAGRC-PGgRc methane programme:

    • Animal Selection
    • Low greenhouse gas Feeds
    • Vaccine
    • Inhibitors

    Breaking News: In the last four months, five lead inhibitor compounds have been shown to reduce methane emissions from animals by 30-90%, which is very exciting. Once proof of concept has been firmly established, commercial partners will be sought to take prototype vaccines and inhibitors through into the hands of the farming community. See more about this 

    Rick concluded by pointing out that 10 years ago, the task of reducing agriculture’s greenhouse gas emissions seemed enormous, and that we should all be proud that we are nearly there.

    Download presentation 

  • 1315 Peter Janssen, Principal Scientist (AgResearch)

    Peter gave an interesting overview of how ruminants produce methane and the strategies that are being investigated for reducing, or even eliminating, this methane.

    Feeds which lead to reduced methane production have been studied and the science team now have a fairly good understanding of why feeding brassicas lowers methane emissions. It is due to changes in the rumen bacterial community.

    Breeding for low methane animals is also progressing well and a number of reasons for the differences in emissions have been discovered.

    Vaccine and inhibitor development involves in-depth knowledge of the rumen methanogens in order to decide how to target and knock them out. Genomic studies have aided this work and also investigating rumen contents from around the world has helped to identify the prime candidates.

    The vaccine and inhibitor programmes are currently in the midst of animal trials and, given recent positive results, the teams are hopeful that proof of concept will be established very soon.

    See more about the progress in the inhibitors programme 

  • 1340 John McEwan, Principal Scientist (AgResearch)

    John provided further detail about the low methane emitting sheep breeding programme.

    There is excellent rationale for this strategy given that for most farmed species (plants and animals) genetics contributes around 50% of the farm system economic improvement. Genetic change is also extremely low cost, permanent and cumulative.

    The programme has established low and high emitting sheep lines and studied them intensely. The data shows that methane emissions from the low emitters are heritable and repeatable, with the low emitting sheep having similar or higher productivity, smaller rumens, different rumen microbial communities and lower VFA concentrations in the rumen.

    The programme has also investigated different options for measuring animal methane emissions, given than the respiration chamber method is time consuming and expensive. Alternative cheaper and more flexible options have been identified.

    The next step for this work is to investigate how best to incorporate the low greenhouse gas trait into the New Zealand sheep industry breeding programmes. The science team will then work on transferring their learnings to dairy cattle and deer.

    Download presentation 

  • 1405 Tim McAllister, Principal Scientist at Agriculture and Agri-Food Canada

    Tim presented an international perspective on the methane research being conducted globally.

    There is research being conducted to investigate both:

    (i) technologies to reduce emissions and
    ii) ways to increase efficiency across the globe.

    It appears that New Zealand has one of the most focused and coordinated programmes.

    Tim then focused on a couple of the more promising strategies including the methane inhibitor, 3-NOP, being developed by DSM Nutritional Products in Switzerland. This feed additive has shown a 60% reduction in methane when mixed with feed, but has to be fed continuously to achieve this reduction. The company are currently looking for any associated productivity changes that may be attractive to farmers.

    Nitrate is also being investigated as a feed additive. This has the potential to be toxic if fed in high quantities, therefore scientists are looking into possible encapsulated formulations to ensure slow release of the product.

    Probiotics are also an interesting area of research, with more studies required.

    Tim concluded his talk by indicating that there is still a lot to learn about the microbes in the rumen and what they are actually doing. Maybe we need to rewrite some of the textbooks based on new data that is emerging?

    He also proposed a suitable definition for sustainability:

    Sustainability: when everyone is happy.

    Greenhouse gas emissions are just one part of the whole picture of environmental, social and economic factors when it comes to “sustainable” future agriculture.

    Download presentation 

  • Animal variation project provides wealth of information

    pdf Animal variation project provides wealth of... (0.66MB) 

  • From tiny bottles to grazing sheep and cows

    pdf From tiny bottles to grazing sheep and cows (0.90MB) 

  • Identifying "friendly" methane inhibitors

    pdf Identifying friendly methane inhibitors (0.79MB) 

  • IDing Livestock Gut Microbes Contributing to Greenhouse Gas Emissions

    News release from DOE JGI, 17 June 2014 excerpt

     "...not all ruminants are equal when it comes to greenhouse gas emissions. It turns out that the amount of methane produced varies substantially across individual animals of the same ruminant species. To find out why this is so, a team of researchers led by the US Department of Energy Joint Genome Institute (DOE JGI) deployed high throughput DNA sequencing and specialized analysis techniques to explore the contents of the rumens of sheep in collaboration with NZ's AgResearch Limited to see what role ruminant "microbiomes" (the microbes living in the rumen) play in this process.

    The study was published online June 6, 2014 in Genome Research."


    • The NZ Agricultural Greenhouse Gas Research Centre and the NZ Pastoral Greenhouse Gas Research Consortium made the methane screening data and animal resources available.
    • The NZ Fund for Global Partnerships in Livestock Emissions Research funded the work done in NZ to support the objectives of the Livestock Research Group of the Global Research Alliance on Agricultural Greenhouse Gases
    • The DOE Office of Science supported the sheep rumen research at the DOE JGI.
    • The data from the study complement the genomic sequences being generated from the Hungate1000 project, which seeks to produce a reference set of rumen microbial genomes from cultivated rumen bacteria and archaea, together with representative cultures of rumen anaerobic fungi and ciliate protozoa.

    Full news release  

  • Mitigation of methane NZAGRC Conference 2012

    pdf Mitigation of Methane (0.50MB) 

  • Piecing together the rumen methanogen puzzle

    pdf Rumen methanogen puzzle (0.68MB) 

  • Technology transfer could help reduce methane emissions from animal waste storage

    pdf Technology transfer (0.59MB) 

  • The methane-free rumen - the solution to all problems?

    pdf Methane rumen (0.23MB) 

  • Delving into rumen 'soup': identifying targets to mitigate methane


    What's really in a rumen? It's probably something that most people haven't given much thought to. However, in the search for methods and technologies to mitigate methane produced from ruminant animals, this is a key question.

    The rumen of a typical NZ ruminant animal contains a complex ‘soup' of chewed-up plant material, saliva, drinking water, plus a vast array of microbial species. Methane, the potent greenhouse gas, is produced in the rumen by microbes known as methanogens. They use hydrogen, another gas that is produced by other microbes like bacteria that break down ingested feed. By converting hydrogen to methane, the methanogens get the energy they need to grow.

    Sandra Kittelmann and Henning Seedorf, along with the rest of the rumen microbiology team at AgResearch, have been delving into the rumen contents of a wide range of NZ sheep and cattle to investigate the microbial communities that live there. By accurately identifying and classifying rumen microbes, and looking for similarities and differences in types and abundances between animals, the search for targets and strategies to reduce agricultural methane is being advanced.

    A key outcome of the team's work has been the development of a taxonomic framework to enable classification of the methanogens from the rumen, and from other animal and human intestinal tracts. This work has been recently published in PeerJ ( Setting up the framework was a long, and sometimes tedious process, with many of the organisms initially unclassified and most requiring new names. However, the completed classification provides a map that allows researchers to identify the methanogen species that are present in a sample from a rumen. "We may not know what they all do yet", says Sandra, "but we can identify what we've got and what we don't have. Sometimes it's incredibly useful to know what we don't know".

    The first use of the new classification was to identify the major methanogens present in NZ ruminants. Surprisingly, regardless of species and diet, there turned out to be a limited diversity of methanogens present. This has big implications for vaccine and inhibitor development. If a new vaccine or inhibitor targets and knocks out the major methanogen groups, it has a high likelihood of working across all NZ species. Currently a Global Rumen Census project (funded by the Global Research Alliance) is underway. Led by Gemma Henderson and Peter Janssen, it aims to survey the diversity of microbes present in rumen samples obtained from a range of locations and farming situations around the world. If the same major methanogens turn out to be globally common to ruminants, any new technologies developed in NZ could be used internationally to help make a real impact on agricultural GHGs.

    New taxonomic frameworks for rumen microbes have also been instrumental in a recently published study investigating the microbes present in the rumens of naturally high- and low-methane emitting sheep ( The team were hoping to find differences in the communities present, with the expectation that there was something special about the high-emitters. However, unexpectedly the results showed that it was the low-emitters that had additional, different strains of bacteria present.

    After some time spent examining the results of the study, it was deduced that there are actually two types of low-emitting sheep. In the more abundant type, bacteria which don't seem to produce hydrogen have muscled their way into the rumen. Less hydrogen means less methane. The animal breeding team, led by John McEwan, have found that the low-emitting sheep tend to have physically smaller rumens, so current thinking suggests that feed passes through the smaller rumens faster, and the non-hydrogen producing species can establish themselves better under these conditions.

    As for the second type of low-emitting sheep (as classified by their rumen microbes), the team are still working on an explanation for this. Sandeep Kumar, a PhD student funded jointly by the NZAGRC in NZ and Teagasc in Ireland, is currently unravelling this issue.

    Investigation of rumen samples is a pivotal, underpinning part of the NZAGRC-PGgRc methane programme. With major vaccine and inhibitor trials planned during the next year, understanding the effects that these are having on the methanogens present is very important. So Sandra and her team will continue to receive and study as many rumen samples as they can handle for the foreseeable future, feeding back their valuable results and insights to the rest of the methane team.


  • Low GHG feeds: latest research shows that forage rape can make a real impact


    Could forage rape, a brassica crop, hold the key to understanding what and how to feed animals to reduce their greenhouse gas emissions?

    A wide search has been carried out to date for animal feeds that reduce GHGs. For a long time everything studied either had no effect or contained some sort of inhibitory compound, but was impractical as an animal feed. For example, garlic has been shown to reduce methane emissions, but is not an agronomically viable forage crop. Grain is known to lead to reduced emissions, but a large proportion of the diet needs to be grain (>65%) to see a reduction. Not a viable option for NZ farmers. Some fresh forages evaluated in New Zealand, such as white clover, have given inconsistent responses when fed to sheep.

    Researchers had begun to think that any type of fresh animal feed would result in the same amount of methane for the same amount of dry matter. That was until some species of brassicas were studied and gave a surprising result.

    Field trials have shown that diets based on 100% forage rape, a type of brassica, can reduce methane emissions per unit of feed from sheep by as much as 30%. Currently the reason for this is not fully understood. Brassicas contain compounds that could act as potential inhibitors of methanogenesis, but all the data so far suggest they are not causing the reduction in methane. It seems that the reduction is due to the way that the feed is being fermented in the rumen.

    David Pacheco and Sunny Sun, with their team, have been following up on this observation with the aim of working out what it is about the brassicas that leads to a drop in methane. Once this piece of the puzzle has been solved, the goal is to be able to identify and develop feeds and feeding practices that result in reduced GHG emissions and can be counted in the national greenhouse gas inventory.

    The research team has been investigating how increasing levels of forage rape in the diet affects methane production. In contrast to grain, preliminary observations from indoor trials with forage rape suggest a linear reduction in methane yield as the proportion of forage rape in the diet increases. If confirmed, this result would mean that feeding of forage brassicas can lead to a reduction in methane emissions at a larger range of dietary inclusion levels than previously thought. The results also suggest that reductions in methane observed in brassicas may occur through a different mechanism to those elicited by feeding grains.

    The research is being extended to include more brassica species, as all those studied to date appear to have reduced methane emissions to some degree. One prediction is that the decrease is due to readily fermentable carbohydrates present in the brassicas. This suggests that researchers should look at other forage crops with this characteristic. Therefore, one of the next feeds to be studied more closely is fodder beet. This crop has been growing in popularity in recent years and the results of any GHG trials will be of interest to NZ livestock industries. Results will also help to inform the search for new feeds and feeding strategies that can be included in the NZ inventory.

    While the team expertise is focused on methane, the project team is linking with other experts to have an integrated, wider view of what the impact is for whole GHGs. For example, Pacheco's team has also been looking at the impacts of brassica feeds on nitrous oxide emissions from urine deposited onto soil by grazing animals. This is being done in conjunction with the nitrous oxide experts in AgResearch and funded by MPI through its Sustainable Land Management and Climate Change (SLMACC) programme. To bring all these findings together a parallel project led by Stewart Ledgard, also part of the SLMACC research fund is using the data generated to do a full life cycle analysis of alternative feeds, like brassicas, that require cultivation and application of fertilisers. These processes can also produce GHGs, and their impacts need to be known as well.

  • Tiny organism a big challenge to methane researchers

    Much effort and intellectual grunt is going into solving the livestock methane emissions problem. Peter Burke reports on this science challenge facing New Zealand.

    A TINY micro-organism one thousandth of a millimetre long is proving a huge challenge for scientists in New Zealand and overseas.

    It's called a methanogen and it produces methane in the rumen of farm animals which they emit when they belch. That methane in the atmosphere contributes to the global warming now causing massive problems.

    The agricultural sector accounts for 46% of New Zealand's emissions, a serious challenge given our large ruminant population.

    New Zealand scientists hope within five years to develop on-farm technologies to help reduce methane gas emissions from cattle, sheep and deer.

    The Pastoral Greenhouse Gas Research Consortium (PGgRc) and the New Zealand Agricultural Greenhouse Gas Research Centre (NZAGRC) are working to solve this problem. Their target is to lower emissions 5% below 1990 levels by 2020 and cut them by 50% by 2050.

    One scientist working on methanogens is Dr Peter Janssen at AgResearch, Palmerston North.

    Janssen says the rumen of animals is where feed is held and fermented by a complex community of different micro-organisms including methanogens. These live on the hydrogen gas that is a by-product of the rumination process; the methane they produce is no use to the animal so is expelled during belching.

    "These methane producing micro-organisms are evolutionarily distinct from the other parts of this complex system including the ruminant animal. They are biologically different - promising if you are trying to develop a strategy to eliminate those without harming any other part."

    Trouble is it's difficult to develop a vaccine or any sort of inhibitor, Janssen says.

    The science challenge is underpinned by continuous investment by the PGgRc and NZAGRC, funded by the government and the primary sector.

    Janssen says it takes a long time to build up knowledge and expertise in this area - a clear understanding of methanogens, in part by growing them in a laboratory.

    Various scientific strategies are being worked on and trialled. These including breeding animals that produce less methane and studying different feed types for their effects on the amount of methane an animal produces.
    Our scientists have bred animals that produce less methane. Various brassicas are found to reduce methane emissions, to a limited degree. Scientists are working on a vaccine and an ‘inhibitor' but a solution is still five years away.
    Janssen says New Zealand researchers' contribution is significant and the quality of their work world class.

    "Similar research is being done in Australia, Canada, to some extent in the US and some EU countries [but there is no] comprehensive programme. We have a programme of hedging our bets with low impact, low risk and high impact, high risk strategies.

    "No one else has programmes applicable to our agricultural systems so we have to look after our own and make sure we develop things that work in our farming systems."

    There is no guarantee a solution developed overseas would work in New Zealand given the unique nature of our farming systems.

    Side Bar :pdf Breathe in, now breathe now (0.10MB)

  • Technical Manual on Respiration Chamber Designs

    Technical Manual on Respiration Chamber Designs
    Released: March 2012
    Edited by: Cesar Pinares & Garry Waghorn

    Download here 



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