Despite spending most of their time standing harmlessly in paddocks, cows have become known as major contributors to global greenhouse gas emissions.
The burping, farting bovines have been embarrassingly held up as an example of the inherent unsustainability of large-scale agriculture.
With over 1.4 million cows, Australia’s dairy industry accounts for around 10 per cent of agricultural emissions, and roughly two per cent of the country’s total emissions, most of which is methane from livestock.
On the average dairy farm in Australia, cow burps account for well over half of all greenhouse gas emissions.
So, is there a way for farmers to join the emissions reduction revolution, when the emissions are built into their very stock and trade?
At the Ellinbank SmartFarm Research Facility in Victoria, Agriculture Victoria’s research director, Professor Joe Jacobs is trying to do things differently.
Using Ellinbank’s 430-cow functioning dairy operations as a testing ground, Jacobs is looking to see if he can reduce the environmental footprint of dairy farming and create a roadmap for other farmers to follow.
“We’re trying to achieve carbon neutrality. And we’ve set ourselves an ambitious target of achieving net zero emissions by 2026,” Jacobs said.
Traditional emissions reductions initiatives such as onsite renewable energy generation through wind, solar and hydro, and using electric vehicles can only make so much difference when energy accounts for just 16 per cent of operational emissions.
The more important, and difficult, approach is reducing the emissions of the cows themselves.
Jacobs explained there are three main ways this can be done, “through feed additive, through genetics and through feed efficiency.”
The emissions cows create come from the process of digesting their food, so by modifying the diet of the animals, the amount of emissions they create can be reduced.
Dietary supplements placed in the feed, such as cottonseed, brewers’ grains, cold-pressed canola, hominy meal and grape marc, as well as feeding cattle higher amounts of wheat, have all been shown to reduce methane emissions.
Most famously, trials are being done with feeding cows a seaweed additive called Asparagopsis, which is a native red macroalgae that has already been shown to reduce methane emissions from beef cattle by up to 80 per cent.
Increasing the efficiency of farming operations through genetics and other programs is another way to reduce overall methane emissions.
“The other one is lifetime efficiency of the animal,” Jacobs said.
“Can we actually make a difference with newborn calves, bringing cows through to weaning and actually setting the animal up, setting the rumen environment up for that long term mitigation of methane emissions?”
Manure waste is another area Jacobs is looking to tackle emissions, despite attributing for only around 12-13 per cent of emissions.
Biodigesters can be used to turn waste manure into electricity, although generally require several operations to join forces in order to make them financially viable.
According to Dairy Australia, a biogas plant is in the process of being built on the NSW South Coast, and when complete will connect 18 dairy farms in the area to one main plant to convert their manure into electricity which will then be used by the farms with the excess fed into the grid for community use.
(Correction: this is not Australia’s first biogas plant as was initially reported)
Victorian dairy farmer and Dairy Australia board member, Graeme Nicoll pointed out that over the past 30 years farmers had been able to cut emissions from cows by 40 per cent.
“Better breeding and feeding of cows has a significant impact on that enteric methane, which is our largest greenhouse gas emission,” Nicoll said.
“There are more opportunities for better breeding and feeding of cows to further reduce those emissions.”