Science makes big strides towards reduced methane from cattle

The Californian study, details of which have just been published in the open-access journal PLOS ONE, found those substantial environmental benefits can be secured without any compromise to meat quality.

The largest reductions occurred with a high seaweed-supplemented, low-forage diet, which lowered methane production by as much as 80 per cent.

Notably, cattle achieved normal growth rates while consuming less food, suggesting that seaweed-supplemented diets could help farmers improve efficiency, reduce costs, and reduce methane emissions all at once.

Scientists in both Australia and the United States said the growth rates and meat quality element was critical, because while the technology to reduce emissions was coming down the pipeline at a good speed, uptake on-farm would only occur if it was commercially viable.

Some estimate feed additives such as seaweed could be commercially available and 'common practice' on farms within five years.

Australia's red meat industry is on a path towards being carbon neutral by 2030.

Researchers from the University of California fed 21 Angus-Hereford beef bullocks their usual diet of hay, grains, and corn, supplemented with either zero, low, or high concentrations of red seaweed, or Asparagopsis taxiformis.

The quantity of methane, hydrogen, and carbon dioxide released by individual bullocks was taken for 21 weeks. The seaweed supplements reduced methane emissions by between 45 and 68pc.

There was no statistical difference between treatment groups for rib eye area, nor were there any effects found between the groups in moisture, protein, fat, ash, carbohydrates or calorie content of strip loins. Mean scores of all sensory attributes - tenderness, juiciness and flavor - by consumer panels were not significantly different.

Lead researcher Breanna Roque said while there was more work to be done, the results are very encouraging.

"We now have a clear answer to the question of whether seaweed supplements can sustainably reduce livestock methane emissions and its long-term effectiveness," she said.

The researchers identified the next steps for the use of Asparagopsis as a feed-additive being to develop aquaculture techniques in ocean and land-based systems globally, each addressing local challenges to produce a consistent and high-quality product.

Their report said processing techniques were already evolving.

Transportation of the processed or unprocessed seaweed should be kept to a minimum, so cultivation in the region of use is recommended.

Professor Frank Mitloehner, from UC's Davis Department of Animal Science, said work on finding ways to reduce the greenhouse gas emissions of the livestock sector were progressing very well globally.

Prof Mitloehner will speak at the big beef industry event Beef Australian in Rockhampton in May.

He also said a lot of research was now finding its way into practice.

"Our dairy industry in California, for example, has reduced methane emissions by 25pc over the past three years with new practices, including trapping biogas and converting methane into fuel - referred to as renewable natural gas," he said.

He said society support for incentivising this type of research - and adoption - should be operating at full steam.

"If people really care about climate, not just about getting rid of cows, they should support the livestock sector. It is a sector that clearly can actually reduce warming," he said.

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