Better sheep genetics cheaper than trees to get rid of greenhouse gases – Stuff

It would cost less to reduce methane emissions by breeding better sheep, than by offsetting greenhouse gases through carbon forestry, new research shows.

The scientists at AgResearchs Invermay Agriculture Centre who recently made this calculation had already been using portable chambers that could measure the methane sheep belched out for a number of years. This research showed that some sheep emitted less methane than others.

For a recent study by the centres researcher Suzanne Rowe rams that emitted lower levels of methane were bred to low methane-emitting ewes. The study compared the emissions from low emitting sheep to flocks bred from rams and ewes that emitted high levels of methane. The study showed low-methane sheep emitted 10% to 12% less methane than the high-methane animals.

It was calculations from these studies that found it would be cheaper to reduce methane in the agriculture industry through sheep genetics, than through carbon schemes that relied on forestry for offsetting.

READ MORE:* Capturing bulls' breath could help breed lower-methane cows* Lower methane cows... from a catalogue?* Low methane New Zealand sheep coming to a farm near you

John McEwan, animal genomics researcher at AgResearch, said initial calculations showed that the cost to reduce a tonne of methane equivalent through breeding low emitting sheep was $1.72. The calculations were done using conversion factors as used in the emissions trading scheme.

This is markedly less than the $85 per tonne CO2 [equivalent] being paid by the emissions trading scheme currently. It is this $85 per tonne CO2 [equivalent] value in the emission trading scheme which underpins New Zealands forestry conversions and is expected to rise higher in future, McEwan said.

There are limitations to using sheep genetics to lower emissions.

Reduction through better genetics would only mitigate part of the Governments proposed methane emission reductions of 10% by 2030 and 24% to 47% by 2050. Other methods would also be needed and would cost more per tonne of methane emitted, McEwan said.

Gerhard Uys/Stuff

A mix of low and high emitting sheep at Leon Black's farm in Southland.

However, forestry also had defined limitations, McEwan said.

Forests could not continuously absorb the extra methane emitted from fossil fuels for many decades. Forests were a limited short-term fix, while the country transitioned to low carbon energy sources, McEwan said.

Similarly, there were practical limits to reducing methane via sheep genetics. New Zealand had to find a manageable path to being net carbon zero by 2050, or more correctly restricting temperature change to a given agreed value. It had to do this at minimal cost to the economy, and avoid rapid swings in prices especially for leveraged asset values like land, McEwan said

There was untapped potential to make faster genetic gains in the sheep industry and there was a compelling case that this method should be aggressively pursued, McEwan said.

According to the study, low-emitting sheep would not find their way into the national flock immediately and there would be no significant reduction of emissions for the first five years in New Zealands commercial flock as there would be genetic lag effects, and because of low adoption rates of new genetic technologies.

In 2007 Southland sheep breeder Leon Black was one of the first to ask if there were differences between the levels of methane that sheep produced.

Black said it made sense, because there were always many variations in any animal population. Some sheep produce more milk than others, or converted feed into meat more efficiently, he said.

There was therefore the possibility that the internal digestive workings of sheep also differed, Black said.

When the question was first asked, the theory needed to be quantified and answer a number of questions. Firstly, was there variation in how much methane different sheep produced? If there was, was it repeatable. If it was repeatable, was that variation consistent? And importantly, would the variation be passed on to the offspring via genetics, Black said.

To all these questions the answer was yes, Black said.

Gerhard Uys/Stuff

Sheep breeder Leon Black says he hoped that instead of reducing flocks by 10% to meet the Governments climate target, genetics improvements would mean the flock could stay the same size, but produce less methane and still produce meat and wool for a profit.

For farmers who grow wool and meat another question was also important. Would animals bred for lower methane produce better wool or meat, or less wool or meat? The answer was that lower methane producing sheep converted feed into wool and meat much more efficiently, Black said.

Black had now been involved in measuring his flock since 2008. Low methane-emitting rams from his flocks were already finding their way into the flocks of wool and meat farmers and would produce daughters who inherited lower methane-emitting genetics, Black said.

Progress would take time as offspring got half of their genetic traits from their fathers side and half from the mothers side, Black said.

Here is the original post:
Better sheep genetics cheaper than trees to get rid of greenhouse gases - Stuff