Despite the hype around red seaweed being the holy grail for reducing methane emissions from cattle, there are some big hurdles to its uptake in the beef business.
The National Farmers' Federation says there currently exists a cost-prohibitive barrier to action with anti-methanogenic feed supplements.
It says that barrier can not be overcome without an incremental increase in the price of animal products produced with a lower carbon footprint, a consistent improvement in animal performance and/or a substantive carbon mitigation payment.
These challenges were spelt out in a submission to the federal government on its agriculture and land sectoral plan from NFF.
The plan, one of six, will feed into the Net Zero 2050 roadmap and 2035 emission reduction targets. Other plans are being done for industry, electricity, transport, resources and the built environment.
The NFF submission listed a suite of actions being investigated or already playing out on farms that aim to reduce emissions and build carbon stores on land.
They include soil sequestration, slow-release and coated fertilisers, conservation tillage, precision agriculture, electrification, biofuels and improved animal genetics.
Top of the list, however, is anti-methanogenic feed supplements - namely the seaweed asparagopsis and 3-Nitrooxypropanol or 3-NOP.
Big money is being invested into seaweed-based supplements, including CH4 Global's $20m facility at Louth Bay in South Australia.
NFF said a lot of research had been poured into the technology and the results were encouraging but the observed successes were dose and geographical dependent.
Anti-methanogenic feed additives, nevertheless, appear to be the dominant mechanism of interest by the government and international organisations in supporting agriculture to reduce its emissions, NFF chief executive officer Tony Maher said in the submission.
Two red seaweeds - asparagopsis taxiformis and asparagopsis armata - have demonstrable real-world high-inhibitory effects on methane production and a number of other seaweeds also have high mitigation potential.
Studies involving sheep, beef and dairy cows report decreases of methane production of up to 98 per cent when diet is supplemented with asparagopsis.
But there are hurdles, the NFF submission points out.
Firstly, research regarding body mass gain and the safety aspect of asparagopsis remains vexed, with some studies indicating no bromoform residues in sheep or beef meat and others reporting accumulation of iodine and bromide in dairy milk and health problems in sheep .
Secondly, the emissions involved in producing, harvesting, processing, storing and transporting seaweed at scale must be considered to determine the viability and net greenhouse gas intensity of adoption.
And finally, economically affordable solutions remain scarce.
Mr Maher said feeding cattle seaweed was not straightforward.
Only 1.25 million cattle are in feedlots, or just 4.36pc of the national herd. On average, Australian cattle spend an average of 50 to 120 days in a feedlot.
While some studies demonstrate an inhibition of methanogenesis of 50pc or greater is possible with 1pc or less asparagopsis in the diet, dietary supplementation can only be done in feedlots as the current science dictates doses need be administered on a routine daily basis to maximise inhibitory effects.
"These factors all diminish the beneficial impact of this technology," Mr Maher said.
"There also exists supply and logistical issues on how to get the product to farm in substantial quantities at an affordable price.
"This is a major limitation of feed additives, and one unlikely to be adequately addressed in a timely manner by market forces alone. It will require government support and targeted investment."
In a nutshell: Asparagopsis cannot be viewed as the single solution toward reducing emissions from agriculture.