Wednesday, April 24, 2024

Cool customers dive into sheep genetics programme

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World-first ‘Cool Sheep’ project gives every NZ sheep farmer the chance to use genetic selection to reduce GHG emissions.
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Sheep and beef farmers Russell and Mavis Proffit have a strong interest in research and development and were one of the first North Island farms to sign up for Beef + Lamb New Zealand’s Cool Sheep programme. 

The world-first project, funded by BLNZ, the Ministry for Primary Industries (MPI) and supported by AgResearch, aims to give every sheep farmer in New Zealand the opportunity to use genetic selection to reduce greenhouse gas emissions in their flock. The Cool Sheep programme’s environmental selection index will allow farmers to select for low-methane-producing sheep as part of a balanced breeding programme with other important production traits. 

The Proffits’ highly successful Raupuha sheep stud at Mahoenui in the King Country produces rams and bulls for commercial sheep and beef farmers around NZ. 

The family have been breeding Perendales since 1977 and also run Romdales, SufTex and Suffolk. They have invested significantly in their breeding programme to produce elite facial eczema (FE) tolerant rams. The farm is also part of BLNZ’s Informing New Zealand Beef (INZB) genetics programme. 

“I enjoy research and being able to help with that,” Russell said. 

“I like to be able to give our clients options, so if someone is looking for a lower methane ram – for instance, if they are doing measuring for their meat company – then it’s good to be able to tick that box for them. 

“I’m also interested to see if there was any link between methane production and facial eczema. So, in the first year we took rumen samples and FE tested before we ran the sheep through the chambers. It’s about building up data until you have enough to analyse and that takes a few years.”

There has been significant interest in the voluntary programme among farmers. BLNZ is oversubscribed with farmers who want to use the portable accumulation chambers (PACS) to measure the methane emissions from their stud animals. 

More than 20,000 rams have already been tested and interest has been expressed in testing a further 5600 rams during 2024.  

The chambers are transparent polycarbonate boxes. Air samples are taken during the time the animals are in the chamber and the methane concentration is analysed. 

“BLNZ bring the chambers to the farm and we put the sheep through in groups of 12 at a time,” Russell said. “For the first two to three years, they did it twice a year and now it’s once a year.

“It takes a couple of days. We weigh the sheep first and I try to get a good mix of range of sizes in each group. Then they go into the boxes for about 40 to 50 minutes and it picks up what gas they are putting out. 

“In terms of outcomes from the programme, I would like to see us breeding sheep that produce lower methane but are efficient in healthy traits, with no compromise around growth and performance. Ideally an animal that eats less grass and still performs well.”

Dan Brier, general manager farming excellence at BLNZ, said the programme is progressing well. 

“It is really pleasing to see the level of interest from breeders and there are lots of sheep out there now with a methane breeding value. We have provided guidance for farmers that want to select for low methane today, and in the future that will be easier with an environmental index.”

However, he advises that farmers should be cautious about selecting for low methane alone.

“Beef + Lamb New Zealand Genetics and most geneticists do not recommend that.” The ‘low methane’ trait will not be included in the NZ Maternal Worth (NZMW) index in the foreseeable future and the index is not affected by low-methane sheep. 

The programme builds on learnings from a 12-year programme funded by the Pastoral Greenhouse Gas Research Consortium and NZ Agricultural Greenhouse Gas Research Centre. 

Metrics from AgResearch’s Woodlands breeding flock also demonstrated in practice how genetic gain is 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 per cent. High-methane sheep have slightly higher body condition scores. 

“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. 

“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 using the NZMW index, the low selection line is around $12 more profitable than the high selection line, excluding any value on the actual methane.”

The NZ-designed chambers to measure sheep methane are increasingly being rolled out in other sheep-meat producing countries, such as the United Kingdom, Ireland and Australia. 

Russell said that during an international trip with the INZB programme last year, including attending the 2023 Beef Improvement Federation Research Symposium and Convention in Canada, he found that methane was a hot topic of conversation. 

“I was surprised by the amount of talk about methane at the symposium. We tend to think it’s just New Zealand that is worrying about it but the rest of the world is too.”

The project brings significant co-benefits for BLNZ’s wider genetics programme and will include setting up a system that can deal with hard-to-measure traits like meat quality and immunity more effectively. 

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

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