Low methane-emitting sheep a reality in New Zealand

A breeding value for methane emissions was launched in November 2019 and was the outcome of a 10-year breeding programme funded by the Pastoral Greenhouse Gas Research Consortium (PGGRC) and the New Zealand Agricultural Greenhouse Gas Research Centre.

AgResearch scientist Dr Suzanne Rowe has been leading the research programme and says for the past ten years, they have been running two closed flocks side-by-side, a low methane emitting flock and a high methane emitting flock.

Each flock consisted for 100 composite ewes (identified as either low or high emitting through the Central Progeny Test programme) and the management of each flock has been identical.

Dr Rowe says on average, they have identified a 11% per unit of feed eaten difference in methane emissions between the two flocks, but most importantly, it appears there is a no difference in the health, productivity or profitability between low or high emitting sheep.

“We are seeing more lean growth, carcass yield and wool production in the low methane sheep without any negative trade-offs.”

This breeding programme, which confirmed that methane emissons were heritable, allowed for the establishment of a breeding value for the trait which was incorporated onto Sheep Improvement Limited database (now nProve) last year.

Stud breeders have been embracing the opportunity to measure the methane emissions in their stud animals through AgResearch’s portable accumulation chambers.

Each animal spends 50 minutes in the chambers twice within a 14-day interval. The resulting measurements are used to calculate a methane breeding value.

Breeders will pay for the first measurement and PGGRC will fund the second.

The AgResearch team have been measuring around 2000 sheep every year, but this number was impacted by COVID-19 restrictions this year.

Cost off-set to incentivise breeders

Mark Aspin, General Manager PGgRc, is encouraging stud breeders to take the opportunity to have their rams measured and to start making use of the breeding value.

He says while PGgRc has been pleased with the initial momentum with breeders, they want to encourage as wider use of the methane selection service as possible and further build on existing knowledge of the correlations and impact with other productivity traits accumulated.

“Adding to that understanding will further advance the economic impact calculations that is needed to confirm the benefit of methane selection.

“We have provided a cost offset for a limited time (mid 2021) to encourage all breeders to make the commitment and find out where their flock might rank for methane”

To find out more, breeders can go to the dedicated website: Sheep Methane Measurement.

Investment in commercial flocks of the future

Southland ram breeders Leon and Wendy Black were amongst the first commercial stud breeders to invest in measuring methane emissions and generating methane emitting EBVs their Blackdale stud rams.

It was a significant investment. Measuring 84 rams, which represented nine of their main sire groups, it cost them $7,500 for the two tests, without labour. A further $7,500 was paid by PGgRC as part of its breeder incentive scheme, making the total cost $15,000.

With no demand for this trait from their commercial clients, it is money Leon and Wendy will not recoup- yet.

Leon says as a ram breeder,he is breeding now for his clients’ needs five years down the track and while as yet, there are no economic incentives or market signals for breeders or commercial farmers to breed low methane sheep, he believes it is just a matter of time.

“It’s a dilemma.

“While I feel I have an obligation to try and reduce greenhouse gas emissions, no client has ever requested it. But breeding is about looking towards the future.”

As a former Director of both B+LNZ and the PgGhgRC, Leon has had insight into the development of the methane reduction technologies and believes that for the sheep and beef sector, genetics are the most effective way of meeting the sector’s emission reduction targets.

“The most cost-effective way for the sector to reduce its emissions is to lean that way and breed animals that produce 10% less methane.

“It takes time but you’ve got to make a start and I learnt a long time ago that you are more likely to improve something if you focus on it than if you don’t.”

Now the Blacks have breeding values for methane emissions, they will be using these as yet another factor in their selection process with the aim that their clients will be better off in the future.