Research case study, feeding fats and oils

​Case study – Department of Agriculture, Fisheries and Forestry, Australia’s Farming Future
Climate Change Research Program (CCRP)

Oils ain’t oils

Victorian dairy producers trialed natural feed additives to improve dairy conditions and reduce their carbon footprint.

New research conducted in Victoria indicates that adding dietary fat supplements, such as brewers grain, a by-product of the beer-making process, to cattle feed could reduce methane emissions by 15 to 20 per cent.

With each grazing dairy cow burping up to 600 grams of methane per day, researchers, extension officers and farmers worked on ways to reduce these emissions without compromising animal production and costs.

Dr Richard Eckard, Associate Professor and Director, Primary Industries Climate Challenges Centre at the University of Melbourne said methane is a gas which is 25 times more powerful than carbon dioxide.

“Australian livestock producers have already reduced methane emissions through better feeding practices, genetic improvements, increased productivity and more efficient production methods,” said Dr Eckard.

He headed a project under the Reducing Emissions from Livestock Research Program (RELRP).  Funded through the Australian Government Department of Agriculture, Fisheries and Forestry’s Australia’s Farming Future: Climate Change Research Program, and managed by Meat & Livestock Australia. RELRP comprised of nearly 40 projects that investigated emissions profiles of livestock and the practical on-farm options to significantly reduce emissions and simultaneously increase productivity.

Dr Eckard said the aim was to develop practical feeding strategies that dairy farmers could implement to curb methane emissions.

The project investigated several waste products that were high in oil including whole cottonseed meal, cold-pressed canola meal, brewers’ grains and hominy meal.

“For every one per cent of oil added to a ruminant's diet it translates to a three and a half per cent reduction in methane emissions,” said Dr Eckard.

“In the case of whole cottonseed, it not only significantly reduced methane emissions but also increased milk production by 15 per cent, milk fat by 19 per cent and milk protein by 16 per cent.”

Dr Peter Moate, dairy nutritionist with the Department of Primary Industries (DPI) in Victoria said while adding fats and oils to the diets of cattle appears to be a promising way to reduce emissions and increase production, it would be of most value when pasture is limited in quantity and has a low nutritive value.

Adding, the reduction in methane emissions won’t work when the feed source is already high in oil.

“In Spring, our ryegrass gets up to around 5 per cent oil anyway and you can't go above 7 per cent, so you don't have as much margin,” said Dr Moate.

“But in Summer you might have pasture with only 1.5 per cent oil, so that gives you a bigger window to add oil.”

“In that scenario, adding 5.5 per cent oil could reduce emissions by 15–20 per cent. It would also increase milk production due to the slow-release energy provided by oil.”

The research results could have implications for other livestock producers as well, according to Dr Moate.

“This rate of methane production applies to a wide range of common diets regardless of whether cows are in early or late lactation, and this relationship also applies to beef cattle,” said Dr Moate.

“Drenching cows with tannin can also reduce methane emissions by up to 29 per cent. But, tannin is very bitter and we need it to be something that appeals to the animals palate,” he said.

Graeme Nicoll, ‘Montrose Dairy’ a pasture based dairy farm at Fish Creek in south Gippsland produces around 1.5 million litres of milk each year from his 280 cow herd.

Graeme is a 2009 Nuffield scholar recipient and is a progressive dairy farmer committed to a vibrant future for dairy farmers and dairying regions. He has travelled internationally looking at other dairy systems and ways to evolve his dairy farming at Montrose.

He said some of the fats looked at in the study are already in the diets of many dairy herds.

“We’ve been feeding used vegetable oil in our herd for the past two or three years”, he said.

“It is a relatively cheap energy source, but it also keeps everyone in the dairy happy because there isn’t as much dust coming from the feed rations.”

He said although he is interested in the research, he wouldn’t necessarily add fats to a cows’ diet simply to reduce methane.

“The current economics of agriculture and dairying, in particular, is that we can’t make a change unless there is an economic benefit,” said Mr Nicoll.

“What we also need is the economic analysis that shows the return on investment for adding fats or oils is competitive.  If you can show me the research which says changing an animals’ diet will increase milk production, then I’ll do it.”

“I believe the dairy industry is in a better place than other industries to make changes as we have our cows contained twice a day and can influence their diets quite easily.”

The study of dietary fats and oils forms part of a larger program to develop a suite of methane abatement strategies for ruminant production systems in south eastern Australia. The project has also successfully developed a reliable way to measure methane on a larger scale and on different breeds, or types of animals such as beef cattle and sheep.

Last reviewed: 4 November 2019
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