WHILE there has been a large amount of research carried out to determine the feed efficiency and greenhouse gas emissions of cattle in a feedlot situation, measuring this in the area that matters most to the majority of cattle producers - in the paddock, while grazing pasture - has proven much more difficult.
That is, until now.
Ground-breaking research is currently being undertaken by a collaboration between the NSW Department of Primary Industries (DPI) and the University of New England (UNE), to assess the feed efficiency and methane emissions of a mob of Angus yearlings grazing at the DPI's Glen Innes Agricultural Research and Advisory Station.
Principal research scientist at the NSW DPI's Beef Industry Centre, based at UNE's Armidale campus, Dr Robert Herd, said the research was the first of its type in the world.
"While other people have tried to measure feed efficiency on pasture, there has never been a very precise way to do so," he said.
"We now have some new tools available that will allow us to take measurements without greatly disturbing the normal grazing habits of the cattle."
The research is being carried out by Dr Herd and UNE PhD candidate Jose Velazco, from Uruguay.
"Jose is doing much of the day-to-day work and it's great to have a good young scientist working on the project," Dr Herd said.
Part of the new technology being used in the project has come from the United States, in the form of the C-Lock GreenFeed Emission Monitor, or GEM.
This unit is used to measure the methane emissions from each animal participating in the trial.
"The animals put their face into a hood, and a fan behind their head then blows air over their face," Dr Herd said.
This air is then collected, and as 95 per cent of methane emissions from cattle come from their nose and mouth, the air is analysed to determine each animal's methane emissions.
To encourage the cattle to place their head into the hood, they are given a small amount of feed pellets as an incentive.
"The pellets trickle out over a couple of minutes, and act like a little lolly to keep the animal's head in the hood," Dr Herd said.
The system also makes use of the radio frequency identification (RFID) ear tags fitted to the cattle as part of the National Livestock Identification System (NLIS).
"The cattle have their NLIS tag read as they enter the unit, so we can identify them, and also to see if they've been into the unit recently," Dr Herd said.
"As the pellets are only used as an incentive to get them to enter the unit, we want them eating pasture and not filling up on the pellets, so if they were in the unit only two hours ago it won't release any pellets.
"We're aiming to have the cattle coming into the unit for about five minutes at a time, about three to four times a day.
"This gives us a good indication of how much methane each animal is producing."
The data collected by the machine is sent back to the offices at UNE using 4G technology in almost real time, while cameras also monitor what is happening at the unit and transmit the footage to Armidale.
"We can watch the video footage, and if there's any problems we can call the guys at Glen Innes and get them to go and fix the problem," Dr Herd said.
The feed intake monitoring component of the experiment uses a similar system to the GEM, this time developed in Australia and manufactured by Wagga Wagga-based company Proway.
As with the methane monitoring, a small amount of pellets are fed to the cattle, and their intake again automatically limited using the each animal's RFID tag.
These pellets have a "marker" added to them, which passes through the cattle's digestive system and is excreted in their faeces.
"Two times each week for a 12 week period, we collect faecal samples from each of the cattle and analyse the amount of the marker in each sample," Dr Herd said.
"The less diluted the marker is, the less feed the animal has eaten.
"So if the animal has a high amount of the marker in their faeces, we know that they have eaten less feed."
By also monitoring the weight gain of each animal, the animal's feed efficiency can be determined.
Previous methods of testing feed efficiency in pasture-fed cattle had involved dosing the cattle with a gelatine capsule or bolus almost daily.
"In the past you almost had to bring the cattle back to the yards every day, which was a big disturbance to them," he said.
"With this trial, they're still out in the paddock and we're not constantly disturbing them.
"It's a nice, natural, voluntary method, which is a significant advantage."
Dr Herd said the technology that was being used in the project had the potential to have many other applications.
"In the future it could be used to deliver medication or other products," he said.
"You could precisely dose an animal with whatever you wanted to give it, completely automatically.
"With advances in computer power it can also deliver information directly to your office almost in real time, which is technology that wasn't available a few years ago."
The cattle being used in the project are Angus yearlings, an even mix of steers and heifers, and have been bred in the DPI's Angus herd at the Trangie Agricultural Research Centre.
There has been a focus on feed efficiency in the Trangie herd for the past 15 years, and it is the only herd in the world known to be bred for superior feed efficiency.
"Cattle from the Trangie herd are, on average, 15 per cent more efficient that the average animal," Dr Herd said.
"There's a difference of 30pc between the highest and lowest efficiency animals in the herd, and while the research to determine this has been carried out in the feedlot, we will hopefully see the same on pasture.
"We would expect these cattle to be more efficient on pasture, and hopefully this work will confirm that."
After their period in the pasture phase of the trial, which finishes just before Christmas, the steers and heifers will then head to UNE's Tullimba Feedlot at Kingstown, where their feed efficiency on grain will also be measured and correlations between their pasture and feedlot efficiency can be drawn.
"We're really hoping to see some strong correlations between their efficiency on pasture and in the feedlot," Dr Herd said.
"We're hoping to develop cattle that are more feed efficient and produce less greenhouse emissions, which is a win - win for both producers and the environment."
