Elaine Fisher reports on an Australian project aimed at substantially reducing cows’ methane emissions.

Australian research to develop biopolymer devices inserted in the stomach of cattle to deliver a continuous low dose of a gas-reducing bioactive could prove useful for New Zealand farmers, AgResearch’s science objective champion for climate change adaptation and mitigation, Dr David Pacheco says.

The University of Queensland and Department of Agriculture and Fisheries (DAF) collaborative project is funded by Meat & Livestock Australia (MLA) and the MLA Donor Company Limited, to help producers meet the target to make the meat industry carbon neutral by 2030. It is hoped the $7.5-million project will substantially reduce methane emissions from cows.

Research lead Professor Mary Fletcher from the Queensland Alliance for Agriculture and Food Innovation (QAAFI) says the aim of the research is to develop biopolymer devices that can be inserted in the stomach of cattle to deliver a continuous low dose of a bioactive.

While AgResearch in NZ is not researching biopolymers for delivery of methane inhibitors Pacheco says: “Slow-release technology is interesting and could help expand our options for delivering methane inhibitors, developed in New Zealand and elsewhere, in our grazing systems.

“As part of our research on compounds that could be fed to livestock to reduce methane emissions, we know that technologies for extended delivery of the compound in the animal’s rumen will be useful in Aotearoa’s grazing systems.

“In contrast with indoor feedlot systems where animals can receive additives via their feed throughout the day, in grazing systems the opportunities to offer supplements containing inhibitors are limited.”

Fletcher says researchers want to develop the technology to fit in with the normal management strategies of northern cattle producers. The research team will engage with cattle producers at every stage of the process and is looking for people to be involved to ensure a practical solution for the industry.

“We want to find a solution that doesn’t create a major impost in these extensive pastures where daily dosing is simply not practical.

“We’re hoping that the producers can make it part of their six monthly or annual programme, so when they bring the animals in for weighing and assessment treatments that this just forms part of the normal cycle.

“The treatment could be administered in the yard before the cattle are returned to pasture without greatly adding to the labour involved.”

The key to the project is the slow-release biopolymer technology, developed in the University of Queensland’s School of Chemical Engineering in a team led by Professor Bronwyn Laycock.

The biopolymer holding the bioactive is used to make a rumen insert — a cylinder-shaped object the length of a human hand. Cattle will be able to swallow the rumen insert which will then sit within their stomach where it will be degraded by bacteria over time, releasing the bioactive and leaving no residue.

Mary says biopolymers are already used in human medicine for implantable drug delivery systems. “The rumen of an animal is a completely different environment, but we’ve proven that the biopolymers can stand up to bacterial activity for a number of months.”

Before a trial is conducted in cattle, Department of Agriculture and Fisheries researcher Diane Ouwerkerk will use a laboratory fermenter to mimic the conditions in a cow’s rumen to test the rate at which the biopolymer cylinders will degrade and release bioactive.

Australian Minister for Agricultural Industry Development and Fisheries and Minister for Rural Communities Mark Furner says the biotechnology could be a game-changer for the beef cattle industry.

“In extensive grazing systems, supplements are normally delivered through licks, with little or no control of intake by individual animals.

“The ability to ensure each animal receives a sustained dose of a methane-reducing active agent over an extended timeframe would be a fantastic win for the beef cattle industry, helping it achieve its goal to reduce methane emissions – particularly in cattle grazing extensive pastures.

“If successful, this biopolymer biotechnology could be used to administer other types of treatments to cattle.”

MLA managing director Jason Strong says the red meat sector in Australia has made tremendous strides towards emission reductions.

“MLA will continue to invest in new technologies and techniques to achieve carbon neutrality by the end of the decade, without compromising livestock numbers.

“The CN30 strategy works hand-in-hand with industry’s vision to double the value of red meat sales as a trusted source of the highest quality protein in the next 10 years.”

Mark Aspin, senior adviser NZGHG and environment research says we are tackling the same challenge with the NZ Inhibitor Development Programme.

“An additive’s ability to reduce methane emissions relies on its potency and how long it is active in the rumen,” Aspin says.

“For maximum effect, it needs to be in the rumen at all times – which is what happens in Total Mixed Ration (TMR) and so blocks the formation of methane by methanogens. “

Methane production follows the animal feeding – it goes up after they have eaten and falls away as they digest the grass and using the inhibitor as a feed additive will have a narrow opportunity within Kiwi farm systems unless we can make the active inhibitor last several hours in the rumen.

“We have been exploring intraruminal delivery using capsules or bolus and have several inhibitor classes being developed with delivery to grass fed systems the focus.”