Researchers Suggest "Breeding Out" High Methane Emissions
Researchers have identified the genes and gut microbes that contribute to greenhouse gas emissions from livestock. The identification of these genes can help researchers understand why some animals produce far more emissions than others of the same species.
According to researchers at the Joint Genome Institute (JGI) and AgResearch Limited's Grasslands Research Centre, the unprecedented and record breaking carbon dioxide gas emission levels that the world is currently scrambling to correct, is only part of the battle against greenhouse gases.
Methane gas (CH4), a greenhouse gas that is frequently overlooked, has increased in average world volume by an estimated 50 percent compared to pre-industrial levels, according to the US Environmental Protection Agency (EPA). Alarmingly, this gas is far more potent than carbon dioxide (CO2).
"Pound for pound, the comparative impact of CH4 on climate change is over 20 times greater than CO2 over a 100-year period," the EPA reports.
Still, capping CH4 emissions is a difficult task. Over one fifth of the world CH4 emissions come from livestock - animals necessary in feeding a hungry world. Aside from asking the whole world to go vegan, there is little lawmakers can do about the issue.
However, according to a study recently published in Genome Research, there could possibly be a solution.
For some time now JGI researchers have noticed that while some livestock produce dangerous CH4 levels, similar herds produce barely any at all. Sheep, they found, are infamous emission producers, especially in countries like New Zealand where sheep outnumber people seven to one.
Because of this, the research team focused on sheep populations for their study.
Comparing sheep with low and high methane emissions, they quickly found that chemical reactions spurred by microbes in the animals' guts caused methane gas production.
A closer examination of these reactions revealed something even more startling.
"It's not so much the actual composition of the microbiome that determines emission - which conventional wisdom would suggest - but mostly transcriptional regulation within the existing microbes that makes the difference," JGI Director Eddy Rubin said in a statement.
Essentially, this means that methane production can be genetically controlled.
Screening and breeding for low methane-producing sheep is still underway, but the researchers hope that one day farmers will begin to introduce low methane-producing animals into their livestock populations.
Graeme Attwood of AgResearch Limited, senior author of the study, concluded that "if everything went well you could expect introduction of the low methane trait to begin in three years, and for there to be slow but incremental changes to the sheep industry in subsequent years."
The study was published in Genome Research on June 6.