Low methane sheep genetics

// Breeding and Genetics

More than 100 farmers, rural professionals and international researchers recently took part in a webinar about breeding toward low-methane genetics as part of Beef + Lamb New Zealand’s Cool Sheep programme.

image of sheep infront of cloudy mountains genetics pic only

The Cool Sheep project, funded by the Ministry for Primary Industries (MPI) and supported by B+LNZ and AgResearch, is a world-first project that aims to give every sheep farmer in New Zealand the opportunity to use genetic selection to reduce greenhouse gas emissions for our national flock. 

The high level of participation in the webinar, led by Dr Suzanne Rowe, a senior scientist at AgResearch, and Dr Jason Archer, Genetics Specialist - Livestock for B+LNZ Genetics, reflects the significant interest in the programme, both among New Zealand farmers and globally.   

In addition to the insights about low methane genetics, farmers also learnt more about using the nProve tool to access genetic information for their farm business.  

B+LNZ is investing our time and expertise in this work to provide tools for farmers to manage and reduce their ruminant methane emissions. A number of farmers have also told us this is important to them. 

This research is accelerating the identification of low methane farms in the breeding sector to increase the supply of rams to lower sheep methane in the national flock.  

Despite participation in this programme being voluntary, the response from many farmers has been enthusiastic. We are over-subscribed with farmers who want to use the portable accumulation chambers (PACs) to measure the methane emissions from their animals.  

However, we also recognise there are concerns among some farmers about the programme, including that other beneficial traits could be compromised for low methane.  

On the webinar, Dr Rowe and Dr Archer addressed some of the concerns. Dr Rowe presented both peer-reviewed and new science to help farmers understand what the impact of using low methane rams on their farms could be.   

Farmers and other attendees had the opportunity to ask questions of the science team on the webinar. 

A number of those were about methane measurement metrics and policy, outside the scope of the Cool Sheep Programme. Dr Rowe made the analogy that discussing the methane metrics in this context was like talking about whether to measure a car’s speed by comparing fuel. A faster car is faster, and a lower methane sheep produces less methane, whatever the metric. 

Dr Archer described and answered questions on the Cool Sheep Programme’s environmental selection index. 

This will allow farmers to select for low methane producing sheep as part of a balance breeding programme with other important production traits. Some farmers have described selecting only for low methane, but Beef + Lamb New Zealand Genetics and most geneticists do not recommend that.   

Dr Rowe described the ways in which lower methane sheep differ from high methane ones. This knowledge has been gained though a 12-year programme funded by the Pastoral Greenhouse Gas Research Consortium (PGgRc) and the New Zealand Agricultural Greenhouse Gas Research Centre (NZAGRC). 

Dr Rowe presented metrics from the AgResearch Woodlands breeding flock, demonstrating in practice that genetic gain was not adversely affected by adding methane emissions to the selection index. 

We learnt that low methane sheep are leaner and have a slightly different fatty acid profile in their milk and fat. They have less carcase fat and an improved dressing out percent, while high methane sheep have slightly higher Body Condition Scores (BCS). 

Lower methane sheep grow more wool. Low methane sheep were also shown to have larger intakes than high methane animals despite high methane animals having larger rumens than either the low methane flock or the control animals. 

The difference in methane emissions from individuals within a flock has been found to remain consistent regardless of diet, region or weather. The ranking of animals stays the same.  

Sheep bred for low methane emissions as part of selection lines are also proving to perform economically better than sheep bred for high methane emissions. When compared using the New Zealand Maternal Worth (NZMW) index, the low selection line is around $12 more profitable than the high selection line.

As more breeding flocks are measured for methane, B+LNZ Genetics and AgResearch will continue to monitor the impacts on commercial breeding flocks.  

This online webinar event was a great opportunity to provide farmers with valuable insights, hear directly from industry experts and learn about the available tools that can be used with ram-buying clients who are interested in low-methane rams. Farmers interested in watching a replay can find it on Beef + Lamb New Zealand’s YouTube channel or through the B+LNZ Knowledge Hub. 

Farmers tell us they value B+LNZ’s research and extension investment. At 40 per cent of our overall budget, we’re focused on delivering tangible research outcomes so sheep and beef farmers can increase their productivity and profitability.