Transcript of webinar: Cutting methane in grazing systems
Heather Field:
Okay. Hello, everyone, and welcome to today's webinar, which is on Cutting methane in grazing systems: What works and what's emerging. My name is Heather Field, and I'm a climate change service development officer with Agriculture Victoria and will be facilitating today's webinar.
Before our presenter begins, just a few housekeeping items. The webinar is being recorded and will be made available after today. Currently, we have everyone muted just to stop background noise. So if you do have a question, please use the chat function, which is currently explained on our screen, and we'll make some time at the end of the presentation for your questions. We do have a big audience joining us today. So if we don't get to all your questions, we'll take note of those and reply where we can. There will be a quick survey following the webinar. So it will take a couple of minutes to complete, and we greatly appreciate your assistance with completing this.
So, before we commence, I'd just like to acknowledge the Traditional Owners of the lands and water on which we are all meeting, and I pay my respects to Elders past and present. And I'm tuning in from Ballarat, the lands of the Wadawurrung People, and I'd like to acknowledge all the lands on which everyone is tuning in from today.
So, today we have the opportunity to hear more about methane mitigation research that's currently underway by Agriculture Victoria. And I'm very pleased to welcome our presenter today, Professor Joe Jacobs. Joe is a research director for Animal Production Sciences in Agriculture Science and Technology, leading programs at both the Ellinbank, Hamilton, and Hamilton SmartFarms. He's internationally recognised for his work in silage quality, forage agronomy, animal forage interactions, and methane mitigation. And Joe has published over 150 peer-reviewed papers and has led the development of the Ellinbank SmartFarm, integrating AgTech systems for real-time monitoring of livestock and emissions. And under his leadership, Agriculture Science and Technology is pursuing carbon neutrality at Ellinbank and showcasing innovative technologies and management strategies to support sustainable livestock production.
So, in today's session, Joe will walk us through some recent trials of emerging methane reducing additives and their potential to reduce methane emissions in dairy cows and other ruminants.
So, with that introduction, Joe, I will hand over to yourself. And thanks for joining and making your time to present to us today.
Joe Jacobs:
Thanks, Heather. And I'm coming to you today from the lands of the Gunaikurnai tribe here in Gippsland.
Okay, so title's probably slightly different to what you just spoke about, Heather, but I think the aim will be the same and hopefully we'll get to the end of the journey together.
First of all, before I do start, I will acknowledge the scientists and PhD students that I do have as part of the team at both Ellinbank and also working across other sites like Hamilton. So you can see on the slide here, this is a team effort, not just one individual.
Okay. What I want to cover today is, firstly, why methane, how we measure methane, some of the background that we've undertaken, particularly here at Ellinbank, challenges of grazing-based systems, what are our options, and then finally getting to some of the recent research we've undertaken, and where to next.
Okay, so why focus on methane? And I've just picked two quotes here, and there's probably hundreds of others I could have picked, but suffice to say, both of these individuals are highlighting methane as one of the largest greenhouse gas contributions from agriculture. And you can see in the small graph at the bottom there that it sits clearly head and shoulders above other greenhouse gas emissions from the livestock sector. So, clearly, it's one we do need to tackle if we want to get anywhere near towards targets that either governments or industry are setting.
Okay. How do we measure methane? Well, there's a range of ways we can look at this. We can talk about outputs or we can talk about concentrations. Outputs, there's probably three key parameters we do use. They are output itself, grams of methane per animal, in this case cow, per day. There is for livestock, beef and dairy, a universal equation, so a published piece of data from Charmley et al. in 2015, and this had a considerable amount of data from Ellinbank in it, which allows us to calculate methane emissions based on dry matter intake. And that equation sits within the inventory numbers that Australia uses and, in fact, other countries also use.
The second way is a methane yield, so grams of methane per kilogramme of dry matter intake. And the third is a methane intensity. So grams of methane per kilogramme of output, whether that's milk or live weight.
And each of those measures can be used and are relevant to different audiences. So, for example, the Victorian government has a focus on net emissions reduction, so carbon neutrality. So the key measure is grams per day. Whereas many of the industries, and dairy is a good example, they've set their focus around methane intensity. So they've got a target of reducing methane intensity by 30% by 2030. Other options are to look at concentrations, which is really, I think, less critical as an absolute measure, but is still important in many other ways. So for example, I know one of my colleagues, Jennie Pryce, her team are looking at options to develop a low methane breeding value, and one of their pathways will be to look at variations of concentration between animals.
Okay, measurement methods we use here at Ellinbank. So, the first is in vitro. So this is a lab-based measurement. And what I've done here is just really put a quick pros and cons on each of these slides. So, it does mimic the rumen environment. We utilise ruminal fluid from donor animals in the small fermentation jars you can see on the right. You can either use a batch culture, which is what I'm showing here, which is either a 24- or 48-hour typical batch fermentation, or there are continuous culture systems which allow movement of material from the fermentation vessel out and new material coming in.
They're very useful as a rapid screening method, helps to identify what might be the most appropriate dose of a particular additive. It also allows you to screen multiple variants of a given product quite quickly and identify which of those show the most promise. It will give us total gas production, methane, hydrogen, carbon dioxide, and also fermentation parameters such as volatile fatty acids, ammonia, lactate. Limitations, it can really be used to eliminate options, provide a relative ranking rather than an absolute identification of the most perfect additive for methane mitigation.
One of the other things that evolved is adaptation of the ruminal fluid itself. So, in some instances, the additive needs to be fed to the donor animals for several weeks to end up with a ruminal fluid that is adapted and aware of that additive and can then subsequently be tested in the in vitro lab. Other products, that's less so relevant, and we'll get onto a little bit of that as we progress through.
Okay, so animal measurements themselves. Respiration chambers, these are the gold standard. A very controlled environment. Gases are measured in, gases are measured out, and that's done in near real time. So we get total outputs of gases, not just methane, but carbon dioxide, oxygen, and in some cases, hydrogen, although not with our system. But importantly, you also get the pattern of emissions and how that changes across the day.
The cons, it's a very artificial environment. We do require very rigorous animal ethics requirements and approvals, a maximum of two to three days' measurement. You can only put small numbers of animals through. So in our situation, we have six of these chambers. That results in very long experiments to get enough animals to have statistical power for subsequent analysis. Animals also need to be trained to the environment, and that can take several weeks, if not longer. And then how do we interpret this information to that of a grazing environment, coming from a very artificial situation to animals actually grazing in the paddock.
The modified sulphur hexafluoride method, or SF6, we can use this anywhere, indoors, outdoors, at grazing. We can run large numbers of animals at any one time. So we max out at about 60. It gives us total methane output per day for five days. So no patterns in this case of emissions, just total output. But we do know it has a very high concordance, around 95% with chambers. So it is a very well validated and verified method.
The cons, the canisters you can see on the back of the animals there, they need changing once a day. Typically, we do that straight after the morning milking. The method itself, sulphur hexafluoride, relies on a tracer gas, which we use as a method to then calculate methane emissions. That relies on a small amount of the SF6 gas being situated in the rumen and releasing over time. That has a finite life. Once that reaches a certain point, then that animal can't be used for further methane studies. Perfectly fine in any other way, but we can't continue to use it for methane work. And the canisters, as they get taken off the animal, need to be analysed through a gas chromatogram. So that's another bit of labour that's added to these.
The final validated methodology is greenfeeds. So they allow relative low input systems. In effect, the animal walks to the greenfeed. When it heads in there, it'll drop a small amount of grain. While it's eating that grain, it measures methane. We can get multiple measures across multiple days. It's really ideal certainly for feedlot or house systems. I think the jury is still out in grazing-based systems.
The cons, it relies on numerous measures over an extended period to have confidence in its accuracy. And this is particularly relevant where diets cause large fluctuations in methane throughout the day. You need enough spot samples across multiple days to have confidence you're fully capturing that range in methane emissions over the 24-hour period. So, hence, relies on visitation by animals. Some animals don't like them. They don't go near them. So that makes difficulty in estimating the right numbers of animals for subsequent analysis.
I think the other part here is consistency of diet over an extended period. And this may not be so critical when you're talking about situations such as a house system where a total mixed ration is being fed. But if you're trying to do this at grazing and you're in a period where the quantity and quality of the pasture changes quite rapidly, then it may be problematic to get a consistent methane measurement.
Just a few other options I've put up here that are, let's say, works in progress, maybe less so for the portable accumulation chambers, so they're the photo on the top right. So in effect, little chambers that, in this case, sheep, but these can be used for beef animals, obviously slightly larger packs than those, where you measure methane over a one-hour period and you do that over multiple occasions.
The other is the bottom left there, a new emerging technology from a company called ZELP. And this is a technology that collects breath from the animals and measures it through the... You can see the small box underneath the neck of the cow there, and measures in situ. This is one we've recently undertaken a comparative test with SF6 and greenfeeds, and we're currently analysing that data at the moment.
And then there's a range of sniffers. And again, the photos in the middle bottom and the bottom right just show sniffers in the dairy, and then one of the scientists holding a sniffer to actually take measurements of the cow while it's there in the stand. And again, the sniffers are more concentrations rather than outputs per se. So, again, it's the different data you get depending on the methodology itself.
Okay. Just moving on, we've been working in the methane space, well, I'm saying here from 2009 onwards. I know there was even a little bit of work prior to that. But that was the first really large national program that we became involved in. So the Reducing Emissions Livestock Research Program. Then there's been subsequent national programs over consecutive time periods, right up to where we are now, where we've got the government-funded Ag Pledge. We've got the Zero Net Emissions in agriculture CRC. And we've also got a range of work we do with other international consortia and commercial partners. But you can see across this time, we've really gone from looking at almost mainstream-type grain mixes or supplements through to by-products, a little bit of work looking at alternate forages. And it's really in the last five or six years where we've started focusing on mitigant additives per se. So really from 2021 onwards.
And just, again, on the background there, and this is just really capturing what I was saying, again, looking at those various methane output measures for a range of supplements and by-products. Also looking at milk responses to those, so not just yield, but fat and protein in particular, and in some cases, functionality of the product itself. I think the summary of all of that work would be the majority of that data showed that some of these supplements do have a positive impact on reducing methane, but most of the effects are very transient and short term. So they really worked by gross changes to the rumen environment. And by that, I mean things like lowering the pH, knocking out some of the protozoa, which is where we know the methanogens like to reside, which means we get a reduction in methane. However, they adapt. It's a very elastic environment within the rumen, so we end up seeing the environment becoming adapted to the low pH and methane slowly creeping up, sometimes within a few weeks, sometimes slightly longer, but invariably those trends and impacts are quite short-lived.
One piece that did come out of the earlier work that was very positive was the feeding of fats, and the bottom left there just highlights that, that every 1% increase in dietary fat percentage was associated with a 3.5% decrease in methane emissions. However, there's a finite amount of fat you can have in the diet, which peaks out at about 6 to 7%, above which we have other negative impacts on rumen function. So it is a method that allows us up to that 15-18% methane reduction. However, whilst you're getting the methane reduction, feeding fats is a relatively expensive option, so it's probably limited in its use and ability to feed those.
The other part of this, and this is really the bottom right, identifying a cohort of animals that are low methane-emitting animals. So you can see in that graph, there's almost a bell, where there is a bell-shaped curve of methane emissions per day from as low as 250 up to around 700. And this becomes important as an opportunity to develop a low methane breeding value, for this case, dairy cows, but certainly the same scenario will hold for other livestock. And this is where we're continuing to do some work with Jennie Pryce's genetics team, and it's really becoming a numbers game now in amassing enough data across enough animals to have confidence in identifying that cohort of low methane emitters and what's different about them.
Okay, so this is where we get to the good stuff now. The last sort of five or six years where the focus has very much been on feed additives, particularly those that are commercially available, but also those that are emerging. Also, some investigation into alternate forage options. And we continue our work looking at other ways to measure methane that potentially have applicability on commercial farms. The focus of the work has very much been around the efficacy from a mitigation potential, whether that's total methane reduction, a reduction in intensity or yield, the impacts on productivity, both milk yield and composition, in some cases, milk functionality. So if we feed these additives, can that milk still be used for processing for particular pathways? In some cases, checking milk for residues of the additive. And sitting behind all of this is a continued monitoring of animal health itself.
So, challenges of methane mitigation in grazing systems. We're working with a highly variable feedbase, how much is offered on a daily basis, the nutritive characteristics or nutrient concentrations within that pasture, the pasture type itself, animal selectivity of the feed on offer, grazing management itself, and then the overlay of seasonal changes. So, unfortunately, nothing looks like the top-right picture there all year round, and there are parts of the year where it looks more like the bottom picture. So, clearly, challenges. Then you add on top of that, how do we supply the additive to those grazing scenarios? So what's the delivery mechanism? What's the efficacy of the product and how does it interact with the basal feed supply, the pasture itself, particularly given we've just gone through a list of half a dozen dot points how that changes and the challenges with that itself.
Okay, so there's a range of mitigation options available. And this table, graph, flow chart, whatever you'd like to call it, really doesn't cover all of those. So there's ways we can focus on breeding, and we've touched on those earlier. There are management systems that can be put in place, managing unproductive livestock, optimising feed efficiency, healthy animals. All of those are givens we should be striving for anyway.
What I'm going to do today is focus more in the diet manipulation space, and I'm really going to take two examples. One of those is the methanogen inhibitors with a focus on halogenated compounds. And the other is dietary supplements and looking at probiotics, direct-fed microbials. And whilst we've researched many of the other areas, I think given the time today, these are two sort of pertinent areas that we can focus on and look at the opportunities within.
So, we kick off with bromoform-based products. And whilst this says efficacy of asparagopsis in pasture-based or pulse feeding systems for lactating dairy cows, some of the data I present here is either bromoform derived from asparagopsis or synthetic bromoform. So, the work we've been looking at has focused very much on what are optimal rates for lactating dairy cows, formulation, bioactivity, what is the methane potential, both immediate, short-term and longer-term, the impact on product, so milk production, compositional changes, how we feed the additive itself, is it economic to do so, are there synergies, stacking opportunities down the track, residues in milk, and that underlying monitoring of animal health and welfare through this.
So, one of the unique attributes of halogenated compounds, and bromoform is an example of that, is that in effect, it blocks the last two steps in the production of methane within the rumen. So it, in effect, inhibits the enzymatic pathway to produce methane. So it's very effective. It's very quick acting, and can result in significant reduction. And in fact, in some feedlot systems, it's been seen up to 90-98% methane reduction in feeding this compound.
One of the key things to note is that immediacy of action is as quickly diminished if you stop feeding the product. So it works from day one, it stops working the day after you feed it. So there is no carryover effects from it, and there's no lead in time.
Okay. I'm just going to run through results of some studies that we undertook at Ellinbank. So, in the first case, it was with an asparagopsis oil-based product derived from the seaweed asparagopsis. This was an early lactation study where we had four rates of bromoform fed and a control, a zero bromoform, fed over a 41-day period with measurements over the last five days. And part of the reason for the length of the study was a very slow introduction to the product to ensure animals were eating their prescribed rate of bromoform.
So, we just run through a few results here. On the left, dry matter intake. On the right, milk yield as energy corrected milk. And you can see here that... if you squint and look sideways, you can see a small reduction at the higher rate, the asparagopsis 3 and 4, but none of this data was particularly significant for intake or milk yield.
In contrast, when we look at those three methane output parameters, production yield and intensity, we saw a consistent reduction in methane as we increased the amount of bromoform being offered. So, up at the higher rates, we were up at over 20% and even into the 30, 35-plus percent reduction at the higher rate.
Now, if you think back to, I mentioned earlier up to 90-98% in a feedlot environment, that was being offered in a TMR, total mixed ration-type diet, where we like to say every mouthful had a bit of bromoform in. In contrast, here we are pulse feeding the bromoform twice per day at milking, so early in the morning and mid to late afternoon. And this comes back to how the bromoform inhibits. It's a very fast-acting, but very short-living product. So without regular intake, after two or three hours of the initial feeding, its activity wanes. It's used up. So I believe looking at this data, this is still very promising, getting over 30% mitigation, despite only having those two relatively small windows in which it's a very active product.
But obviously, we've got this other side to these halogenated compounds, and that's residues in milk. So, the graph on the left here is looking at bromine, iodine, and bromoform, and we're just focused on the bromoform today. We have safe drinking limits. So World Health Organisation has a safe drinking limit of 100 parts per million of bromoform. You can see from the graph that we're up at about 7 parts per million at our highest rate. So we're still way, way lower than those guidelines indicate, but there isn't an MRL, a safety limit or a detection limit in milk. So, as such, from a commercial saleable aspect, it needs to be zero. So, having it present in milk is a challenge for us.
In contrast, most of the work that has been done in the livestock industry, so the meat and sheep industry, has very rarely detected levels of bromoform in meat. So there clearly is a different pathway between moving to meat or moving into milk. So this is an area still of challenge for the dairy industry.
Now, the next study I want to just pick up on here is actually a full lactation study that compared an asparagopsis-based product with a non-algal-based product. And these were fed twice daily to 30 animals each across a full lactation. So the bromoform was offered at about 300 mg per day, which was around that second-highest rate in the dose-response study from the start of lactation through to day 140. And we measured three times, once in early, once in mid, and once in late lactation, and these animals were at grazing.
So we measured milk, daily measures of milk, monthly composition measures. Additionally, during those intensive measurement periods in early, mid, and late, we also looked at fatty acid profiles, functionality and residues, measured methane using the SF6 technique. We also took samples of ruminal fluid for fermentation. We did some blood chemistry, also looked at residues in both blood and excreta. So, a very intensive 250-day-plus study.
Some of the key results from this. So, again, the table on the left, we've got early, mid, and late lactation, then the control and the two products. And you could see at each stage, there was a significant reduction in both methane production of grams per day and methane intensity, grams of methane per kilogramme of energy corrected milk. So, at all three times, irrespective of the type of bromoform product fed, they were both significantly lower than the control treatment. And if you look to the right of the slide, what this means is, if we take an average farm of 340 animals, 300-day lactation, that's a saving of about 21 tonnes of methane for the BR-N and about 27 tonnes for the BR-S, which equate to just shy of 600 and just over 750 tonnes of carbon dioxide equivalents. And if I take those numbers and look at that for Ellinbank, that's about a 20-22% reduction in our total carbon dioxide-equivalent greenhouse gas emissions from this farm. So, it can make a significant impact when we're looking at total farm emissions.
Productivity, really not much in it. You'll notice early on the... Apologies, the codes on these graphs are slightly wrong. BR-A is in fact the BR-N, and BR-B is the BR-S. But what it's showing is we did have some challenges with initial feeding of the second product, the BR-S, and this was the adaptation to the product itself. In effect, we tried to introduce it too quickly. And we're still unclear whether it's a palatability issue per se or whether it was an impact on the rumen environment, particularly when we're pulse feeding large amounts twice a day. But the animals did adapt to it. Milk production settled down, and clearly it was just we tried to do things too quickly. And typically, now when we're doing a trial with one of these products, we'll take 20, 24, 25 days to introduce to the full rate and don't seem to have any effects.
Okay, residues. Obviously, feeding this for a full lactation, we were keen to understand what was the impact. And again, we could see residues in milk in early, mid, and late lactation, and they did creep up in late lactation, which I think was a reflection of less milk, more concentrated, and very low, if any, detections within blood, urine, and faeces. The other important thing here was, when we stopped feeding, we measured three days later and there was no bromoform detectable in milk in the treatment that we studied, the BR-S, BR-B in this graph.
And all we've done here is just put all of our bromoform experiments into one graph. So along the bottom axis, we've got bromoform offered per day. And up the vertical axis, the methane mitigation percentage. And it's a pretty linear response. There's a few little outliers there. But when you think about it, this is natural and synthetic forms. This is cows at different stages of lactation. This is cows being fed either hay-based or pasture-based diets. So, there's a range of other factors to take into account with this graph. But I think it clearly shows that the more you feed, the greater the mitigation that you get.
I'll just put all of these up. It's easier that way. So, where are we at with bromoform-based products? We've currently got another full lactation study currently underway that's funded through a American initiative from the Foundation for Food & Agricultural Research called the Greener Cattle Initiative, where we're measuring methane and milk, but we've also got a greater focus on the fate of bromoform. Plus, when the animals do finish, we will continue to monitor them, both their performance in the next lactation and also any health changes over time. And we will also monitor the progeny from these animals as they grow out from calves into heifers and re-enter the herd at a later stage.
We've also got an experiment planned at Hamilton with some of our sheep, where we've currently got a funded piece of work with Meat & Livestock Australia and the Zero Net Emissions CRC, where in 2027, we will stack a bromoform product on top of different forage-based systems to see whether we can get a synergistic impact there. And again, monitor methane, animal growth through lambs, and subsequent meat parameters and residues. So, it's an area we will continue to work on along with many other groups nationally and internationally. And whilst there are clearly challenges with bromoform-based products, there are also plenty of opportunities, but there's a fair bit of work is required from a regulatory perspective to get them as an accepted product, particularly for the dairy industry.
Okay. The next one I want to touch on is the direct-fed microbials. So these are live microorganisms that are used to manipulate rumen fermentation pathways. They can decrease methane by promoting propionate-producing bacteria or enhancing other hydrogen-utilising pathways. They're naturally occurring. There's a range of species and strains available, and they have already been shown to have productivity and health attributes. From a methane perspective, a lot of the previous work has been inconclusive. There's been some positives, there's been some negatives, there's clearly a dietary influence and a strain specificity.
Now, the little table... oh, sorry, the little photo here, image, is just really getting a key point across. One mil, one millilitre of rumen fluid contains about 100 billion bacteria, about 10 million protozoa, and about 10,000 fungi. Now, if you take a dairy cow rumen, it's typically anything from 70 to 100 litres in size. So, that just gives you an idea of the numbers of bugs that are sitting within a room. And I think if we look at this one, what's this one? This is 1×10^18 bugs. So, to affect and manipulate that environment is quite a challenge.
And again, I just wanted to run through a series of studies we've done here, and these are all focusing on a product called MYLO, which is a lactobacillus-based probiotic produced by a Australian company, Terragen. And we did some work with them probably six or seven years ago, and we've done a number of subsequent studies with them. This is the first study we did where we fed this liquid product twice a day at milking. We saw a modest increase in milk yield and energy corrected milk, a modest increase in feed efficiency. And we did see a reduction in methane intensity, but unfortunately, this wasn't significant, but about a 7% reduction in methane. But it was enough for the company to get very interested and look to do some subsequent work with us.
So, the next piece of work we did was we actually had some discussions with them about the formulation and the opportunity to move away from a liquid product to a freeze-dried product. So similar sort of principle that is used for when lactobacillus are used as a silage inoculant. You basically supply it with a freeze-dried product, you activate it in solution and then spray it onto the pasture as it's being collected either into a bale or the pit. So same principle. And these two formulations were fed to grazing dairy cattle for about 40-45 days, and then subsequently we undertook methane measurements.
Again, feed intake and milk production, very little in it, nothing significant there. Methane production, it seemed like the freeze-dried was probably slightly better than the liquid, but again, none of this data was significant.
I guess the challenge with this one was the fact this was done in early spring, cows in early lactation eating a very, very high-quality pasture. So in this instance, this was a very low-NDF spring pasture, around 35% NDF, very low dry matter, 8% to 10%. So in effect, it was a bit like feeding the cows rocket fuel. It just flew straight through them, which would have made an environment that was very difficult for a microbial inoculant, direct-fed microbial, to actually colonise and have an impact upon.
Okay, the next study I want to talk to is a sheep-based one where we used the freeze-dried product from that previous study and fed it to lambs over summer and looked at their methane emissions and their live weight gain.
Again, this was a pasture-based... Well, it wasn't pasture because there was no pasture. It was a hay-based system with the grain mix containing the product fed in a SmartFeeder, which enabled us to manipulate how much each animal got across the day. So it was separated out into eight feeds across the day, and each feed contained a small amount of the product. So, we saw a significant positive improvement in average daily gain, so a productivity gain, and that flowed through to a 30% reduction in methane intensity when the freeze-dried lactobacillus product was fed. So, clearly a difference between a growing animal and a lactating animal, but noting the basal diet, hay versus a very lush, low-fibre, low dry matter pasture.
Okay, so direct-fed microbials. Supplementing the diet of lambs with a freeze-dried product did significantly increase average daily gain. Methane intensity was lower. And the SmartFeeder, which is the technology you can see in the photo there, did allow us to provide a viable way to deliver the product to sheep in a grazing environment. But as I've just said, it remains some questions around growing animals versus mature animals, rumen volume and dosage required. Obviously, I mentioned earlier, a dairy cow's rumen is anything to 70 to 100 litres. A sheep's rumen is considerably smaller, just a couple of litres in size. So it may be possible that such a smaller rumen, it is easier to have an impact and colonise and influence the microbial community. And then, obviously, the basal diet is part of this as well.
Where to next? So, we will continue to work with bromoform formulations, and I mentioned we've got a full lactation study currently underway. We're also working with other commercial partners on direct-fed microbial products. So we're keen to pursue if that is a viable option. We will continue to look at delivery mechanisms for grazing systems, and there's certainly interest in areas such as water delivery, other in-paddock feed options, lick blocks, slow-release options. So there's companies looking at slow-release boli as an option to get additives into the rumen and have effect. We'll continue to look across livestock systems. So while the focus has been very much dairy, we will consider to utilise our other SmartFarm at Hamilton where we have sheep and a small beef herd. We're also investigating feed-based options, so particularly plants that have high plant secondary compounds, polyphenols, saponins, tannins, et cetera, and also essential oils.
We're very keen to look at stacking technologies. So are there, for example, feed bases with particular additives that we can get a synergistic effect and increase mitigation potential? We'll continue to validate different measurement methodologies with a view to looking at those that are applicable to take onto commercial farms where we can collect more farm data and test some of these additives for their efficacy within a commercial setting. We'll certainly continue working with Jennie Pryce's team around the opportunity to identify and develop a low methane breeding value. And whilst the early-life programming had a lot of promise early on, and I guess the interest and the opportunity seems to have waned somewhat, there's still an opportunity, particularly for the dairy industry, if we can actually influence ruminal development, microbial population growth to one that is a low methane-emitting microbial population as opposed to a high emitting.
And just rounding off, I'd also like to acknowledge the range of partners and collaborators we've had over the past five years, and many of these we continue to work with. So whether they're government organisations, both within Australia and internationally, trust consortia like the Foundation for Food & Agricultural Research, the ZNE Ag CRC, RDC such as MLA and DA, and then a range of commercial partners that we've worked on and off with over this period of time.
Thank you. That was a bit of a whirlwind, but hopefully has given you a bit of a snapshot of some of the work we're doing and, in fact, some of the opportunities that may be arising for grazing-based systems.
Heather Field:
Wonderful.
Joe Jacobs:
And I will stop sharing there, Heather, hopefully.
Heather Field:
Wonderful. Yes, you have. Thanks, Joe. That's been a great presentation and great to share that depth of experience and helping ground the science in what's practical and realistic for pasture-based systems.
So, we do have some time now for some questions. And while questions do come in, and there has been a few, we do have about 140 people online, I have actually popped in a link to a new edition of the popular little booklet, Making cent$ of carbon and emissions on‑farm. So, please visit that site if you want to check out the new edition.
So, I have got a question just to kick us off, and it's probably just a generic sort of one about, based on what you've shared today, Joe, what should farmers realistically take away about feed additives in terms of readiness, practicality, and next steps?
Joe Jacobs:
Yeah. And I think to some extent, Heather, that may well depend on the industry you're sitting in. So I think if you said a sheep or a beef system, products that are, for example, halogenated based seem to be more acceptable. So we've certainly got a lot of larger feedlot-type systems who are using bromoform-based products in feedlots because the residue issue does not seem to be there as it is with milk currently. So, I think there is an option there. Obviously, the challenge is how you feed it. So if you're in a feedlot environment, that's great. There are plenty ways you can do that. Obviously, at a grazing-based scenario, they become more problematic, particularly for their short lifespan.
The flip side is, I think some of the direct-fed microbials do offer potential, but again, it's how you get them to the animal in a regular, semi-regular basis so they continue to show efficacy.
I think maybe the other way to look at it at the moment, and this is being realistic, none of them have shown productivity gains. Unfortunately, farmers, as of yet, don't get paid to reduce emissions. So we're caught in this conundrum. There are opportunities emerging, but are they cost-effective yet? And probably that one is, the jury is very much still out.
I think some of the work we're doing at the moment with novel feed-based options, so reintroducing legumes or particular herbs, is offering promise, and that may be a pathway that may be more beneficial to pursue immediately, but keeping a watching brief on the additives.
Heather Field:
Thanks, Joe. We've got a question from Jodi, a more specific one, about the universal equation, whether that's applicable to all livestock, so sheep, goats, et cetera.
Joe Jacobs:
Yeah. And look, it was developed using our dairy data and UNE CSIRO's beef data. So it doesn't include other livestock. So, look, I honestly can't say whether it is equally applicable for those smaller ruminants as it is for the larger ruminants. What I will say there is that some of the data I showed today, particularly when animals were fed that very high-quality, low-NDF pasture, you can almost throw that equation out of the window. So, those animals were eating 23-24 kilos of dry matter, which would indicate they should be producing about 460-480 grams of methane, and they were producing around 300. So, whilst we have the equation, the influence of basal diet is significant.
Heather Field:
Thank you. Now, Richard's got a question about the, I think it's the bell curve that you presented on slide 11.
Joe Jacobs:
Yep.
Heather Field:
With the breeding emphasis, is the metric being used emissions intensity or gross emissions?
Joe Jacobs:
My preference would be gross emissions because I think emissions intensity can distort things. And it was interesting, I was only having a discussion this morning with a commercial partner around almost the same thing, that you can have very high-producing animals with a lower methane intensity than a lower-producing animal, but their total emissions may not significantly differ. So, I think focusing on total emissions is probably a more practical way to approach this as opposed to intensity.
Heather Field:
All right. Thanks, Joe. We've got a question about, will the Greener Cattle work be asparagopsis or synthetic bromoform?
Joe Jacobs:
It's an asparagopsis-based product.
Heather Field:
Okay, great. Thank you. Wendy's got a question about, could these feed additives be administered using a constant-release rumen capsule such as Dynamax, which is used for worms, I think [inaudible 00:50:41]-
Joe Jacobs:
Yep. Yep. So, certainly, slow-release rumen capsules, boli are an area of interest. I think we need to be careful what we might be considering as an option. And by that, I mean, one of the concerns to me with boli is that inadvertent complete breakdown of a capsule or bolus, which does occur from time to time. And depending on the additive, the implications that could have, in effect, flooding the environment with an additive very quickly as opposed to slow release. So, I think these options are being looked at by a range of companies, but they're very much still in the developmental phase.
Heather Field:
Thank you. And we do have Jennie online with... Her question's about, with stacking... Oops, I just lost the question. It's just jumped on me. What do you think we could realistically achieve towards government targets?
Joe Jacobs:
Really good question, Jennie. And I think the jury is out on that. I think if I look at some of the in vitro and early in vivo data with some of the different forage mixes, there could be potential for a 10 to 15 to 20% reduction with the forage base itself. Then, if we can get the right additive on top of that and it's synergistic in its nature, maybe we can get those numbers up towards 30%, which I think would be quite phenomenal. I think there's a bit of a reality check in a grazing environment, how high we set the bar. I think if we were having this discussion five years ago, we would have been talking 50-60% reduction. I'm not sure that is going to be achievable unless something really comes out of the woodwork. But I think through stacking, if we can get the number up to around 30-plus, then we can dovetail that in with a breeding option as another part of the stack, then we can start making some significant inroads into this.
Heather Field:
Great. Michael's got a question about... oh, just wondering how 3-NOP compares.
Joe Jacobs:
Yeah. And look, we've done some work with 3-NOP. I think it would be fair to say that it was... If I look at the two sets of data I presented today, 3-NOP was somewhere in the middle in a grazing-type environment.
Heather Field:
Thank you. Ralph has got a question about, is there much difference in methane emissions between different pastures such as monospecies, ryegrass, or Phalaris, or clover, or multivariate mixes?
Joe Jacobs:
Absolutely. And that's one of the areas that really interests us at the moment. And if you were to put them on a chart, you'd say grasses resulted in higher emissions, then legumes in the middle, and then probably herbs towards the lower end. I think the challenge is, you need this balance between how much you can grow across the year in relation to the mitigation potential. And by that, I mean is, we've identified some herbs that have got really powerful methane mitigation potential, but they may not grow much across key times of the year. So you've got to get a balance and understand really what each of these species can offer you at different times of the year. And then how do you pack those into a mixed sward? How do you look at your farm as a mosaic of how much of different species you may grow where? So, I think that there's a fair bit of work to do in this space, but there's also a very large opportunity.
Heather Field:
Thank you. So, we've got a few more questions, so we'll try and get to as many as we can. And we've got a lot of thanks for the interesting presentation. And yes, the recording will be made available for anyone who wants to go back and revisit anything you've heard today.
We've got a question about, can residues of bromoform be effectively and cost-efficiently removed from milk when bromoform is used as a feed additive to reduce methane emissions?
Joe Jacobs:
This is a question we're tackling at the moment. So, when we have measured bromoform in milk, we've done it from milk collected directly from the animal. Now, that's not necessarily... Obviously, milk gets collected, stored in a vat, picked up in a tanker and taken to a processing plant.
Bromoform is a very volatile product. So we're now investigating, we're actually doing a little bit of study at the moment around, "Okay, if we collect this milk and we leave the lid off the vat or we close it, do we treat it in different ways? What impact does that have on the bromoform content?" One of the things we do know, bromoform has a very strong affinity with fat. So it clearly sits in the fat component of the milk. There are some processing pathways that don't necessarily use the fat part. There are other parts that concentrate it. So, I don't think it's a simple question. "We've measured a residue in milk. What does that mean?" That is the starting point. There's a fair bit more work to do in this space.
Heather Field:
Great. Thank you. Daniel's got a question about, has there been any work done on direct feeding of asparagopsis? And just mentioned there's supplies of the product available now.
Joe Jacobs:
Daniel, I don't know. Historically, we go back... Well, from I know my days in the UK, where we used to see beef cattle grazing on the beaches and eating seaweed. So, certainly, cattle, it's not a novel feed to be used. Whether it was a feed that in its natural format they'd be happy eating or whether you've still got to dry it, freeze-dry it in some way, which is an energy-hungry process, I don't know. I probably can't comment on that one, Daniel, much further than that.
Heather Field:
No, all good. Thank you. And yeah, I will be taking a copy of all the questions. So there might be a couple that we might follow up on afterwards. But I'll ask one more. I'm just having a look.
Paul has made a comment about, given the difficulty in feeding additives, it would suggest focus on genetics shows more promise for practical implementation. So the question is around, what are the characteristics that influence low methane production?
Joe Jacobs:
Well, more feed-efficient animals will probably produce lower methane. And I don't know where... Jennie might want to put something into the chat on this one. But my sense is it's primarily microbial population driven. Clearly, these animals have got a... Well, I would suggest, I won't say clearly, suggest a very different microbial population breakdown, for want of a better word, with maybe different methanogens, less methanogens, or other microbial species that effectively utilise hydrogen so it doesn't go down the methanogen, methane formation pathway. But that's the beauty of research. That's the sort of thing we're trying to understand.
Heather Field:
Thanks, Joe. And we'll jump to one last question from Richard. What is the APVMA's stance on these additives?
Joe Jacobs:
Silence, probably the best way to describe that. So, unless things have changed very recently, there is no requirement to get APVMA approval for a methane mitigant. So, unless you know differently, Richard, and thank you for asking that one, that's my understanding of where things sit. If we say they're a health promoter or a productivity promoter, then it becomes a different question.
Heather Field:
Thanks, Joe.
Joe Jacobs:
And that's typical of you, Richard.
Heather Field:
Thanks, Joe. We are at time, so I will leave it there, and we will have a look at the questions and see if there's any that we can sort sort of answer offline. But I'd just like to thank everyone for joining and a big thanks to Joe for your presentation and being able to respond to all these great questions that have come in via quite a large group online today.
So, just as we close out, if you wouldn't mind completing the short survey that should pop up in your browser when you leave today's webinar, that'd be great. That just helps us improve and make sure that we're meeting the needs for future webinars. And in terms of the recording, we're hoping in the next couple of days that will be made available. So, please feel free to revisit that if you need to follow up on anything that you might have missed and need to re-look at.
So, with that, I'd just like to thank you all again for your time and engagement. And yeah, we look forward to seeing you at the next AgVic climate webinar. Thanks, again, Joe. Great presentation.
Joe Jacobs:
My pleasure. And thanks, everyone, for attending.
Heather Field:
All right. Thanks, Joe. I'll leave it there, and catch you all next time.