Livestock are often referred to as the bad boys of climate change.
But what if farmers could reduce their methane footprint by breeding low-emission sheep?
A two-year preliminary research project at Katanning's $3.8 million sheep feed intake facility, which opened its doors in April last year, has been looking into exactly that.
Now in its first phase, the Department of Primary Industries and Regional Development (DPIRD) and Meat & Livestock Australia (MLA)-funded project will contribute to the long-term development of new Australian Sheep Breeding Values (ASBV), with a focus on sustainability traits.
These traits would help producers select more productive and profitable sheep, while appealing to environmentally conscious consumers.
DPIRD research scientist Beth Paganoni has been overseeing the small team involved.
Among those, and some of the first people to undertake research in the sheep feed facility, are WA's next generation of agricultural scientists Amy Bowden and Brittany Bolt.
The pair presented their early findings at the Katanning Research Station (KRS) showcase in August, which put a spotlight on the latest livestock, carbon emissions and land management research at the site.
"This research is so important as methane emissions represent lost energy for production, and therefore, lost profit for farmers" Ms Bowden said.
"The sheep feed intake facility allows us to investigate the relationships between feed intake, growth and methane production in sheep."
Almost 700 genotyped genetic resource flock weaners have been put through the facility this year, with individual feed intake data captured on half of them.
All of the sheep were acclimatised to an ad-lib custom grower pellet prior to entering the facility, which did not contain any rumen modifiers, so their natural expression of methane could be measured.
During their time in the feed intake facility, the sheep were weighed twice per week to measure their growth and welfare.
The project is an overlay on the station's genetic resource flock (GRF).
Two main sites in Australia host the national sheep genetics project including WA at KRS, and Armidale, New South Wales, hosted by the University of New England (UNE).
The purpose of the GRF is to further develop a reference population to allow for genomic prediction of the Australian sheep industry.
This reference population provides an opportunity to assess genetic components of 'hard-to-measure' traits, that are either too costly or too time consuming for producers to measure on farm.
Example traits include carcase value and eating quality, parasite resistance and reproductive efficiency.
Ms Bowden, Ms Bolt and Ms Paganoni are co-operating with UNE to align the methodology of data collection on their sustainability traits project.
The data collected from both sites will contribute to the development of relevant sustainability ASBVs.
Feed intake findings
Preliminary results from the trial at KRS, indicated that individual feed intake could be highly variable day-to-day, however, sheep were still consistently growing while in the shed.
On average, sheep were consuming about 1.5-2 kilograms of pellets per day, and gaining between 165-230 grams per day.
Individual animals at the same liveweight could also be eating really different quantities to each other.
Ms Bowden said some sheep would binge eat one day and eat less the next, whereas others ate a more constant amount day-to-day.
The feed intake facility offers the unique opportunity to measure the number of times individual animals eat per day, and for how long.
Feeding frequency could be highly variable, with some animals averaging 30 feeds per day, and others averaging 50, for example.
"It is important to understand the relationship between feed intake and growth and production," Ms Bowden said.
"We need to know how much sheep are eating, how often, and how quickly, as this can impact on their ability to digest feed and use energy for production.
"Through our feed intake data we can calculate how efficient individual sheep were at converting feed into growth.
"We also measured body composition, which identifies muscle, fat and bone content, on 300 of the weaners using the sheep feed intake facilities' dual-energy x-ray scanner (DEXA).
"We can combine this body composition information with another scan taken of the carcase post-processing at WAMMCO, to further investigate genetic and phenotypic factors that influence an animal's feed intake, growth and productivity".
So what does this have to do with methane?
Brittany Bolt said sheep have the unique ability to turn grass and forage into high quality meat products, wool and - of course - more lambs.
Ms Bolt said individual animals have different energy requirements, which influences how much they need to eat for maintenance and growth.
She said this largely depended on their physiological state and level of activity.
"Generally speaking, if they're a growing lamb, or if they are pregnant or lactating, they're going to have a much higher energy demand compared to a dry ewe or adult wether," Ms Bolt said
"Even between individual animals of the same age and physiological status, there is variation in how much energy they need for maintenance and how that energy is converted into protein and fat."
Ms Bolt said energy was used differently by individual sheep, which highlighted the importance of measuring and selecting for the most valuable economic traits, such as reproduction, wool and meat.
She said the research team was already aware of variation among breeds and individuals in the economic traits they were measuring.
However, there was also variation in methane production, which is why work was being done to better understand the variation in methane production on the GRS.
How and why are some sheep producing less methane than others and the relationships between growth, body composition and feed intake?
Measuring methane
Katanning's Feed Intake Facility includes a methane measurement shed which houses 16 PACs- or portable accumulation chambers - used to measure methane.
Each pack contains a single sheep for 45 minutes and is lowered into a water bath, which forms an airtight seal to trap all of the gases that are being produced.
The team have been using an Eagle 2 gas monitor to measure methane, oxygen and carbon dioxide at 15, 30 and 45 minute intervals.
"All of the GRF weaners have their methane measured twice in their lifetime," Ms Bolt said.
"Once at post-weaning in December, when their diet consists of dry pasture, oaten hay and pellets.
"Their second measurement is taken after they've spent some time in the feed intake facility, where they are fed a complete ad-lib pellet diet."
Ms Bolt said that this data could be used to rank animals based on their methane production, identifying high and low producers.
By combining these measures with feed intake, liveweight and genetics, researchers will be able to identify the most productive individuals at the same level of intake, with high growth rates and lower energy wastage.
Where to from here?
Next steps in the project involve delving deeper into these interactions, combining liveweight, feed intake, growth rates and body composition with methane.
This will give researchers a better idea or the full picture as to where all the energy is going.
"Animal breeding is such a strategy," Ms Bolt said.
"We are still in the early stages of collecting data, assessing the phenotypic and genetic influences on methane production, feed intake and feed efficiency.
"We also want to understand the relationships between these new traits and our existing production traits."
She added, "when there's variation in population, there's opportunity, which gives us the power of selection for improvement.
"When we have more data, we will be able to work out how to select for lower methane, while also continuing to improve sheep productivity."
The team will continue collecting measurements on the 2023 GRF weaners this upcoming summer and autumn.
Facility features
Spread across 940 square metres with the ability to hold 260 animals, the Sheep Feed Intake Facility at Katanning is the biggest of its kind in Australia.
The facility houses 20 sheep pens and up to 13-head per pen.
It features:
A semi-controlled environment, including AxisTech environment monitors that continuously captures records of temperature, air quality, airflow, and wind speed.
An automated feed delivery system - the first in Australia used in sheep research.
This system is custom-built and can blend diets from four different sources with the capability to allocate different diets to each pen.
Custom built feed units, fitted with eID readers.
As the sheep approach the feed unit, their eID tag is read, the feed unit records the amount of time the sheep has its head in the feed tray, and calculates the amount of feed consumed in every feeding session due to the weighing capability of the feed tray.
This information is sent via Bluetooth to a central computer system.
The combined capability to blend diets for 260 sheep through an automated system significantly increases the research capability through labour and resourcing efficiencies besides performing individual feed intake trials in group pens allowing the sheep to express more social behaviours.
State-of-the-art Portable Accumulation Chambers used to measure the methane emissions of individual sheep.
A Dual-Energy X-ray Absorptiometry (DEXA) machine, to objectively measure the muscle, bone, and fat composition of live animals.
This machine can be used to assess changes in body composition over time.
