Low-methane sheep

A 10-year research study has developed a low-methane-emitting sheep.

AgResearch scientist Dr Suzanne Rowe explains the programme and how they’ve been able to measure and then select for sheep with lower methane emissions. Ram breeder Leon Black talks about working to implement the research at his own farm.

Transcript

Voiceover

AgResearch has been at the forefront of a 10-year study along with the Pastoral Greenhouse Gas Research Consortium and the New Zealand Agricultural Greenhouse Gas Research Centre. The multimillion-dollar programme has also been supported by MPI and MBIE. The organisations have worked together to develop a world-first breed of low-methane-emitting sheep. It’s a significant step for sheep farmers. One result is that Beef + Lamb Genetics have launched a methane breeding value that will provide a practical tool to lower agricultural greenhouse gas emissions.

Dr Suzanne Rowe

This is a project that started 10 years ago when we became interested in whether methane emitted from ruminants was something that was heritable – so passed on to the next generation. So we wanted to know if we could measure methane – that was something that was different between individual sheep – whether we could breed for it and select sheep divergently for high and low methane.

The funding has come from government, from the Greenhouse Gas Centre – and that’s funded by the New Zealand Government by MPI – but also from industry from the Pastoral Greenhouse Gas Consortium.

It’s really important because, in New Zealand, we’ve signed up to the Paris Agreement, we’ve said that we’ll lower our greenhouse gas emissions, and a huge amount of those emissions – 80% of the methane that’s emitted in New Zealand – comes from ruminant livestock. So we really need to understand how we can mitigate that and how we can understand it – the emissions that are coming from our agricultural sector.

This was a world first. We’ve presented this globally. We’ve had interest from the Global Research Alliance who’ve helped us by helping to fund programmes that actually roll this out into other countries, and we’re helping other countries across the world to actually start up their own programmes. We’re really interested in all ruminant livestock. We’re really interested in how this research transfers to cattle and to goats and to deer. So we’re really interested in rolling out this out further.

What we did is screen 1,000 animals through respiration chambers. So it was a very long, very expensive programme to start with. We chose the highs and the lows, and we put them on this farm and we’ve kept them as distinct flocks for the last 10 years. And we’ve bred the highest of the highs and the lowest of the lows, and we’ve just followed them generation after generation. And what we’re finding is that, each year, the lambs that are born, they’re more and more divergent – so the high lambs are becoming much, much higher in methane emissions than the low lambs – and each year, we’re seeing that divergence occurring more and more.

It’s what we call a portable accumulation chamber. It has a fixed volume of air that we know the sheep is going to be really happy and comfortable in. So the sheep goes in for about 50 minutes. We have a measuring device that you would use in a mine. It’s a gas analyser, and it picks up methane, it picks up oxygen and it picks up carbon dioxide. So the sheep goes in, the door is closed and we measure at time zero. We then measure 20 minutes later and 20 minutes after that, and the sheep is released. So it’s very rapid, it’s very straightforward and simple. We wanted something that would work on farm and that would be practical to measure a lot of animals.

They’re surprisingly calm and quiet. We have windows, and that was something that we worked very closely with the ethics committee to look at ways that we could sort of build something that the sheep would be comfortable. They can see each other, and it’s working so far. We don’t have any issues with behaviour.

We bring the sheep in – usually as a young animal – measure it 2 weeks later, and that’s enough for us to get a breeding value that will rank the animal for the rest of its lifetime. We are measuring everything that we would on a research flock and on a commercial farm. So we measure everything from meat quality, growth, survival, reproduction, parasite resistance on both the highs and the lows to see if there are any differences between them.

We haven’t seen any effects on fertility. We haven’t seen any effects on survival. The effects that we’ve seen have been around the energy supply to the animal, which makes perfect sense, because all of this is happening in the gut. So we’re seeing more lean growth in the low line, we’re seeing more wool growth in the low line, and one of the things that we’re seeing that we didn’t necessarily expect is that we see more parasite resistance in the low line. In terms of our small flocks here, we’ve only seen positive changes between the highs and the lows.

We work very closely with Beef + Lamb Genetics. They have a fantastic system where they produce breeding values for the sheep industry. So when this project was started, it was set up right from the start with the intention that eventually, if we had sufficient information, that it would be rolled out through that same platform. So breeders would find it really easy to access, and they could access it in the same ways that they do everything else.

So what’s happened now is that the models and the predictions that we’ve made have been rolled into the beef and lamb system, and now a breeder can have their own flock measured and they can get a breeding value for methane for their rams in the same way as they can any other trait.

Voiceover

Leon Black is a leading ram breeder and former director of the Pastoral Greenhouse Gas Research Consortium. He’s been involved with the project for several years.

Leon Black

The new breeding value, I’ve been explaining to my clientele that this is the start, this is where we benchmark where we’re at. The on-farm impact will be relatively rapid depending on the emphasis you place on the trait. So there are a number of things you select for, and we’ll be able to exit those that are very high emitters and place a little more emphasis on using highly productive sheep with the low outputs.

We’ve got some targets to achieve as an industry – 10% reduction – and that can be achieved using genetic selection. I would imagine in about three generations we should see some serious impact in terms of the overall output.

The level of uptake will again be dependent on both the government and industry’s commitment and farmers embracing it and seeing that there is no negatives in terms of their overall economic outputs. They still need to be, you know, all the bells and whistles in terms of production, sound animals, along with those with the lowest outputs. Some of those results are available now for this year’s sales, and I’m sure Beef + Lamb Genetics along with AgResearch will be incorporating those so that the wider industry will get access, and that’s how we’ll make the progress.

Acknowledgements Video clip courtesy of Showdown Productions.