Join Al & Juddy in this episode as they delve into the four main factors that affect animal intake, and how this may impact your farming system.
From bite size and rate, to grams per bite and grazing duration, there are many factors to consider each with its own influence on animals.
Tune in to grasp how these effects impact your animals.
"In a pastoral system, grazing animals get their energy from grazing forages. Grazing intake, which refers to how much an animal can consume from pasture in a day, is affected by various factors that can make it easier or harder for the animal to consume pasture and ultimately affect their daily energy intake" – Glenn Judson
Juddy Well. Hi there Ally, how are you doing?
Allister Good thanks, Juddy.
Juddy What are we going to cover today?
Allister Well, Glenn, we're going back to our university days and a topic that we ran through. We studied in animal science that we've actually taken on many aspects of that as we created experiments and demonstrated to farmers over the years. So it is the factors affecting intake.
Juddy Oh, I'm glad about that because there's a lot of other experiences back at university that I didn't want to relive, but.
Allister And many of them are involve factors affecting intake, but just not of forage at the end of the day. So Glenn, tell me what is this topic we're discussing factors affecting intake. How would you describe this topic as a whole?
Juddy So if you think about a grazing animal, it's got an energy demand. And so in a pastoral system, the animals getting their energy from grazing forages whether that be grass pasture or a crop that we've grown or whatever. So the factors that affect how much an animal is able to consume from a pasture in a day is what we call grazing intake. And there are a number of factors which make it either harder or easier for that animal to consume pasture, that ultimately affects how much energy goes down the throat of that animal in a day.
Allister So, atleast I am mistaken, this is actually an equation.
Juddy But it can be described as an equation. And essentially, if you looked at the grazing formula intake rate or the amount of forage that's coming in per hour or per day is a function of the size of the bite. It's a function of the rate of the bite, so how many bites per minute and bite size is how many grams per bite, how many bites per minute, and then how long those animals are prepared to graze for. So if you multiply the bite size by bite rate and grazing time, you will approximate the total amount of forage coming into an animal.
Allister Yeah. Cool. So if we start to break those down and just discuss some of the factors that create the variance around those things we were discussing earlier, that bite size has got a couple of parameters of which.
Juddy So, if you think about this, there's those three parameters and bite size is really two dimensional. So bite size can either be the depth of the bite, so how deep into a pasture it can bite. And that is why pasture cover or the length of pasture is really important in terms of grazing
Allister And we'll tease that out later.
Juddy Yep. And the other side is bite width. So if you think about bite depth and bite width you will essentially approximate the amount of forage in that bite. Interestingly enough, while sheep and cattle will have different bite widths, it's not very often that we get cattle. They're able to increase the size of the width of their bite. So kind of smile when they bite. So that's why width tends to be set, it's the depth of bite which is has the biggest influence in terms of bite size.
Allister And as I say we will cover that later and some of the discussion around experiments and the demonstration. But at the highest level it is why that for really high performance animals that are getting an instant return i.e. dairy cows where you have a certain height of cover, why we have pre grazing masses of a certain size because that means they're able to eat their energy demand and eat and access their sheer amount of volume that they need to consume in a day, which is quite significant. A dairy cow eats around.
Juddy Well, if you're thinking it's 18 kg's of dry matter a day that's well into the well over 100 kilograms of fresh weight for those animals.
Allister Of course, and when you start to do that equation, that bite dynamics, the depth of the bite has a big impact on how much they can get per bite.
Juddy Well, actually, it's one of the largest effects. And so if we pick apart that equation a little bit more, what we're saying is bite size is really important that tends to be the bite depth. If you limit that the question often asked if you limit that have those animals got the ability to increase bite rate to compensate for that. And so bite rate is probably limited to about 36,000 bites a day.
Allister Holy smoly. So some very interesting person who obviously has a life had to count that.
Juddy Had to count that.
Allister Oh, my goodness.
Allister 36,000, so that an extreme length.
Juddy It's about the upper level. So that's essentially a bite every second. For eight hours. And so if we say that's the upper limit, it's not often that animals can increase bite rate to account for decreases in bite size. So bite size is king.
Allister So using the analogy with lambs and taking apart the preferential grazing which will cover later. If you pre graze with lambs and let them access first and then bring ewes in afterwards to tidy up our pasture. An example would be those lambs get to maximise their bite depth, intake per bite, they're quite efficient feeders not spending a lot of energy on it, whereas the ewes that come in have to come into a shorter pasture to get there same intake they have to, they're limited to how deep the can graze and therefore they work harder.
Juddy Correct and actually their intake will go down.
Allister Yeah, correct. But because they are a ewe we accept that that's their job to tidy up.
Juddy Yep, and so the other thing that they can do is if we've made it hard from a bite size point of view, they will try and increase their bite rate. And they will also actually lengthen their grazing time. So upper limits of sort of nine or 10 hours a day in terms of grazing. So they can graze for longer. But the message here is that bite size is king, while they can increase bite rate and grazing time, they will never fully make up for it.
Allister The depth of the pasture.
Juddy The bite size. If you drive down bite size, you largely drive down intake.
Allister Yeah, so let's go back to bite rate because we'll tease that out. One of my more favourite pub quizzes from the day is, you know, like what is a normal number of bites that an animal has in a day? And then I'll give you a personal description of a video we took when I was travelling in South America and we counted bites from a dairy cow grazing. But what's an average bite volume in a day?
Juddy If you go 36,000 is an upper limit and that's over sort of an eight hour period by biting a second for each of those, I would say you could probably a little over half of that would be an average dairy cow consuming maybe 120 kilograms of fresh matter.
Allister Something like 12,000 bites in a day was a take home. You know, that's something, that rings bells from those days. And I think that, to be quite honest, that would blow people's minds, that an animal would have to put its head down into the pasture and take 12,000 physical bites a day to get its forage. And all of the drivers of that are dependent on how you present your species or your forage. To put this in perspective, I've got a beautiful video of a dairy cow just so happens in South America, where she obviously came out of the shed into the pasture and we took a video of her grazing and it was constant video of her, her nose touching the ground and never moving off the pasture. How many bites do you think she had before she came up off the pasture?
Juddy Yeah. How many?
Allister In one moment. So in one grazing moment without lifting a head off the pasture, it was chomp, chomp, chomp, chomp, chomp, chomp, chomp, chomp, chomp, chomp. And we recorded it then had to go and count the chomps and it was 55 in one go. So you suddenly you can sort of understand how an animal could get to 12,000 when that was lucky to be 30 or 40 seconds.
Juddy And that's why and if you ever think of it, if you think about the make up of a cow, for example, in terms of having a really large jaw and some powerful muscles around that, that animal's designed for grazing. So it was designed for taking large number of bites because that's how it gets its forage in. So yep, they are quite high numbers but when you go and actually do the maths around the size of each bite and how much they're trying to get in, they do literally have to bite that number of times to get that amount of forage.
Allister And I suppose the relativity to a farmer and to all of us actually is that every effort, has an energy cost, so the easier you can do it the less energy you spend doing it. So we've discussed the bite size, now we're talking about the other two traits, are grazing time and...
Juddy And bite size, bite rate and grazing time.
Allister And so what sort of drives bite rate, just out of interest.
Juddy So bite rate tends to be where those bites, so when you think about when those bites are not very deep, right, and the pastures short what they're trying to do is nip and do a little and try.
Allister Graze faster.
Juddy They try and graze faster. Now that's typically not very successful because increasing bite rate normally comes at a lower bite size.
Allister Yeah and I can imagine the energy to just keep nipping as fast as you can is actually quite high.
Juddy Whereas sometimes, particularly if you're shifting animals on a break, if you actually stop and listen, and if you can hear the slow rhythmic ripping of grass. You can often get a sense, even if you weren't looking at the pasture for how deep that pasture is and how tall it is.
Allister Like I say, this cow was really distinctive. It was a very like a literally is chomp, chomp, chomp and even would do a few, you know, chews while she's keeping a head on the ground. But you could see there was a large amount of feed going in and each using quite high covers and just wouldn't take her head off the ground. It was quite amazing.
Juddy And so when you think about that and you're thinking about trying to get the maximum intake into an animal, because I guess that's the other point that we probably haven't covered. And we should actually state this is, if you are after highly productive animals, that's high milk production or you've got animals growing very fast, or you're in a deer system and you want velvet antler to grow fast or any productive or you're being more productive or highly productive, the one thing is that you must eat more. Because actually.
Allister Your energy demand is high.
Juddy Your energy demand goes up.
Allister And maintenance, and then you've got the extra energy that is left over from the body maintenance to grow.
Juddy Yeah so you need a high energy intake and this is sometimes where I would say a lot of situations where animals aren't meeting our productive expectations. Largely it's because they haven't been able to physically get enough energy down their throat. Some of that has to do with the quality of what's going down, but largely it's to do with how much it's physically going down.
Allister And so grazing time again, another technique that they only expend so much energy to graze for longer.
Juddy The theory is you can offer essentially a dairy cow enough area so that she could get her grazing intake from a bowling green, for example, it would be a huge area. But there's enough forage there to do that. The issue is she's going to work so hard for so long to get there that actually we get this thing called grazing fatigue. We are actually after about 9 to 10 hours, they will stop grazing and accept.
Allister Because the little bit of energy they might be getting doesn't account for how much energy they're using to get that feed.
Juddy Yes. So it's the law of diminishing returns is that year they could graze for longer and get more in. But actually the return they're getting from that is actually quite low. So you'll see this what they call grazing fatigue, where animals actually give up grazing because it's too hard and you tend to find that in short passes and actually as a side, if you're co-grazing sheep and cattle together in the same paddock, that effect comes into play quite nicely because the sheep are able to with these smaller mouth pieces, being able to graze to a lower level. And so the first class of stock that gets impacted by that co-grazing is actually the cattle simply because they are horizon grazers and that pastures getting too short for them.
Allister Absolutely. Then moving out of that, how do we utilise it? We've discussed elements of utilising this, but what comes next in that grazing dynamics?
Juddy So when you think about the ability to harvest so it's the grazing formula, the next bit really is around daily allowance. So how much is actually there to graze, the way it's presented as really important, but how much is physically there to graze? So if we're asking, for example, a dairy cow to graze eighteen kilograms of dry matter, if there's not eighteen kilograms of dry matter there offered to her on a stocking rate basis, then she won't get that. And so I think allowances or the amount that you're offering those animals is really important as well. And I guess to some extent this voluntary feed intake, you know, we may set an allowance of 18 but for some reason it might be bigger animals, they might have a bigger appetite, they could have a higher energy demand, may actually eat more than that. And so we're we go to these situations where we allow animals to eat as much as they can. They can actually demonstrate how much they're prepared to eat. And so a really good example of this is where we've gone to these two and three day kale breaks where we've been saying, well, you know, these dry animals, they've got the ability to eat 12, but, you know, sometimes they can eat 14 kilos. And so we have been under feeding these animals relative to what they are prepared to eat. And so that daily allowance, I think, is really important. Once you set that allowance, once you've once offered that, they will eat no more than that. But because you haven't given the opportunity to do that. So like daily allowance is really key. And again, getting back to that idea that if we've got animals that are underperforming, one of the first things I'd be looking at is have you actually offered was enough in terms of consuming.
Allister This probably moves on to what you're offering the animals. And one of my favourite terms of those days is fractional degradation rates and can you explain what that word represents.
Juddy So there's two things here, I think. In terms of their daily allocation. The other part of that is you can allocate it's actually edible allocation. And sometimes what we've got, we might have a pasture that's three tonne, but there could be a tonne on the bottom, which is brown and inedible or it could be below harvesting heights or in brassicas it could be full of lignin and therefore not consumed. So I think we've got to think about this term, not just an allowance but actually a harvestable edible allowance.
Allister Edible dry matter.
Juddy I think the point that you've touched on is around processing speed. So, you know, we say, well, an animal is able to eat eighteen kilograms. Well, part of that is the ability of the animal to basically process what she's eaten. Right. So that's she needs to ruminate then it's broken down, absorbed through the gut. And so different forages have different speeds at which that happens. And it just so happens that it's the dicotyledons that tend to break down so much faster.
Allister Well they tend to explode, you know, they take about mastication animals chewing them up and then they are broken down into smaller pieces. But when they go into the rumen they tend to break them, split apart.
Juddy Very quickly.
Allister Now, grasses don't do that, do they?
Juddy No, they don't.
Allister They're glued together.
Juddy They're kinda glued together differently. So you've got these dicotyledons that fall apart very quickly.
Allister So just put that in perspective that's things like chicory, plantain, clovers and brassicas particularly.
Juddy So they are the ones that the breakdown speed in the rumen is as much quicker. Grasses tend to break down reasonably quickly, but into strings, you know, they become quite stringy. And so that's not something that's immediately able to move out of the rumen and therefore the resident times can be quite large. And so just to highlight that, there was a little bit of work that we know were comparing these things to put some numbers on it. Ryegrass may have a half life in the rumen, so when half of it's gone around about 6 hours.
Allister This is high quality ryegrass
Juddy High quality ryegrass, you know, 18 kilograms and in 6 hours, half of it's gone. There isn't time for things like plantain and chicory, for example, they're more like two and a half hours. So what you can see is that those animals were probably on those diets, were tuned to grazing sooner and therefore have the ability to eat more in a day. So it's the process change that.
Allister Drives up the total amount of nutrient.
Allister And energy that they can absorb in that period.
Juddy In fact, what I would argue is that, you know, we can make some small changes in terms of energy density of our pastures. So the metabolisable energy, you know, you could go from 11.5 to 12 that would be completely swamped, right, if you had a same quality pasture. But they could eat a third more. So the daily intake is by far the largest driver of total energy intake because although there are some important changes in quality, the magnitude of those aren't as large as those differences in intake.
Allister So given an example, we've talked about 6 hours for a ryegrass plant. You know, there are other grass species. You know, you go to the north and Kikuyu one of those and that can be green when the landscape is hot. But can be quite fibrous, quite low in protein and as an example. But what does that do when it gets inside the rumen?
Juddy Yeah. So again this principle is how quickly this material breaks down. And Kikuyu, for example, some of those summer grasses, you know, green and looking reasonable quality, they could be sticking around for 10 hours. And so when you think about that, you're only really after one or maybe two grazing bouts a day. We know with those.
Allister Because your rumens are still full and still processing.
Juddy Yes, it's what I call the big fat pie theory. There's still something sitting there you’re not returning to grazing sooner.
Allister And to be fair, that would reflect very strongly. So in our careers we've done a lot of finishing, we've finished on chicory, plantain, red clovers, brassicas. And one of the things, particularly on high performance lambs when they are in these systems, is that they are never round. They are what you would actually describe as slab sided. And yet the laying down of meat and the dressing out percentages particularly of our plantain and clover based systems, have consistently shown a 2% increase in dressing out.
Juddy So just to unpack that, the dressing up percentage is really the carcass weight that you get from a known body weight. And some of that body weight is its gut full. And so we're you've got these fast processing forages, what you tend to find is any one time there's less in your gut because it's being processed faster.
Allister Hence they're not round and puffy, which always makes you feel good when you look at them from a distance as long as not bloating and cattle. But when they've got nice round sides on them, everyone's happy. They'll well feed. But actually the better word to be is that well, full.
Juddy They're well full. Yeah nah I agree.
Allister Not necessarily well feed they're well full.
Juddy Yeah. And we can fill them up with a lot of stuff. So I think so that's really useful because on some of those really high performance forages, we can actually if we were setting a slaughter target in terms of live weight, we could probably come back a little bit and get the same carcass weight for that, knowing that we've got forages that are being quickly processed. What you also tend to find in those animals and it's a double edged sword here where we're feeding those high quality forages, particularly the plantains and the chicory, the rumination time of those animals. So that's where animals might sit down and re-chew that material, very much like grass.
Allister Which is a really healthy process, it gets the salvia moving. And that's a big part of the rumen.
Juddy Yep. And so that's really important. And so they would do that in the likes of a chicory and plantain, the rumination time is reduced quite significantly. And that's because by the time the animal sits down and decides it's going to re-chew that material, it's already broken down and gone. The upside of that is that we can return to grazing sooner. As you point out, the downside is that we're not promoting the production of saliva, which is a really important buffering solution for the rumen. And so we can sometimes get around in these situations, some more acidic situations in the rumen that we just need to be aware of. So great from a quality point of view. But you are getting a little bit closer to having some changes in rumen ph which may not be terribly helpful.
Allister That's really hard to pack a part because you're nearly always seeing high levels of animal performance at the very same time that that's becoming a risk.
Juddy So this is when it's going well, it's going well. What you tend to find is we do run into these problems. There are typically some other underlying issues that are coming forward.
Allister Just thinking about this, unless I'm greatly mistaken, red gut in lucerne and possibly to a lesser degree, but possibly in red clover is a direct result of this, is it not? Is it low rumen capacity?
Juddy So in red gut what we're getting here is we're actually getting material that's moving through the gut really quickly. I liken it to a backfire and a car we've got material it's past the rumen where it is meant to be fermenting and starts fermenting further down. So in a car which we get an ignition outside of the cylinder and we get a bang in the exhaust pipe. And this is like having a band exhaust pipe. We've got material that's got out of the rumen it's fermenting further down the gut and that causes a physical twisting of that. And of course, when we physically twist the gut and we can't push material through and the redness is the hemorrhaging of that tissue.
Allister But technically that's because of a very liquid and.
Juddy Fast moving digester down the gut. And so a lot of the time, if we were trying to mitigate that on those very, very high quality feeds, that we might try and slow that by adding fiber, for example, or it has grass along.
Allister And just out of interest there's always a conflict adding fibre because you're only grazing on these species to elevate per head performance. And fibre is by far a lesser quality feed source. So in the aim to fix a few, you can actually drive some of your efficiencies down.
Juddy So the trick here is to feed it at the right rate and for the right period of time. So we want to be slowing this down while we have this very high quality. Those things can change relatively quickly. And so if you know, in the weeks and maybe even months after that event, if we're still feeding it, then that can be quite problematic in terms of dragging the whole quality down.
Allister Average diet down.
Juddy So yeah, that's the fractional degradation rate or the passage speed at which materials are breaking down. And that's why clovers also lend themselves to high intakes and high animal performances. They also break down. It's not the only thing, but it's one of those.
Allister Well leads on really well into the impact of different species shapes and presentation to you know again how does that impact intake and the energy requirement of an animal to get its intake.
Juddy Yeah. So you can imagine that if you've got pastures which have got wide leaves that stand very erect and are easily harvested by the animal they're are going to promote a higher intake simply because the animals can harvest that. And I know you've got a great field demonstration that you've been using over the years.
Allister We should almost break that down in almost a separate discussion.
Juddy But it's a really good demonstration of one the times where we've taken some learnings from the literature and from university studies and actually turned that into a really good demonstration in terms of how we get animal performance out of some of our forages. So again, wide leaves standing very erect. If you think about a plantain plant, it's got a very small stem at the bottom of that leaf and therefore animals can harvest a huge proportion of the aboveground.
Allister From it, 80% of it in one mouthful.
Juddy In one mouthful, if you contrast it to a ryegrass for example, where we've got a very fine leaf atop and quite a big base, it's almost the direct opposite. And therefore for the same aboveground dry matter, it's much harder for them to consume as much of that plant as possible.
Allister And so with that in mind, it's quite obvious that the shape and the presentation, so clovers have horizontal leaves at a higher height. On average, grasses tend to be long leaf blades that, you know, have probably an equal mass across their whole height. Then herbs are quite rounded, large erect leaves. So you've got these different shapes, brassicas have these big round leaves, so you've got this different presentation. What sort of role does preference have?
Juddy Yeah, great question.
Allister And you know, we'll probably delve into the role that preference has initially and then separate that out to discuss one of our demonstrations that we've done with the adjacent monocultures.
Juddy So preference is a really interesting thing because you might assume that preference has a really big impact on animal performance and actually in some respects it does and in others respects, it doesn't. And to go back and define preference, preferences are all about your choice of one species over another. And as we mixed pastures together, we would always create a spectrum of those choices. So where we've got a choice and where animals will eat one thing over the other. That's what we refer to as preference. And it's really only partial preference because it's not that common where we get animals to exclusively eat one thing and not the other. So a really good example of this would be if we've got ryegrass and clover. A lot of the detailed grazing work you might expect that a lamb, for example, would want to eat all clover. In fact, it doesn't, would select a diet it could of about 70% clover and 30% grass. And so if you were offering that to the animal that's what it would select. If you gave it all clover, right, it would grow probably faster. So the fact that it's chosen to eat some grass is really around the fact that it wants a varied diet. Preference, so it doesn't mean to say the grass isn't any poorer or.
Allister Well, technically it could be the host of L three larvae. It could have alkaloids in it, but they are seeking an element of balancing it might possibly fibre, for example.
Juddy So they've got this choice and they'll exhibit it when they can. Another great example is brassicas. So brassicas are on the lower end of that preference spectrum, a little bit like the broccoli with kids.
Allister In saying that not all of them, but leaf turnip, particularly for lamb finishing, which is the leafy turnip, it's a classic.
Juddy But I would say even forage rapes, and again, remember we're talking about preference. It's the other options. If you gave them an option that was higher on that list, they would preferably go and graze it.
Allister To use the leaf turnip as the best example because there is a window of grazing mass, which we sort of believe is about 24 centimetres, maybe 2800 kilograms of dry matter. That is a sweet spot for starting leaf turnip. After that time, it can get quite bitter and we make this comment all the time. We know that the history of live weight gain on leaf turnip is actually really consistent and high. If the weather is not overcast and the fibre and the protein levels aren't too high, dry matter is too low. We can regularly get 280 to 300 grams a day from leaf turnip. However, a lamb won't want to eat it if you open a gate or go into the roughest pasture and just eat the grass ignoring the leaf turnip. And one of the weaknesses at that time of year is that grass is likely to hold toxins, whole parasites, internal parasites. And actually the lamb’s live weight gain or wellbeing could represent a weight gain, could be as low as 80 grams a day and in some cases it could be negative live weight and yet the animal has chosen to reject the leaf turnip in favour of that old grass pasture.
Juddy So the impact that we've got.
Allister And that's our management is to shut the gate and get it onto it.
Juddy Absolutely. So the impact of preference and how that impacts intake is really important because in one way, if we're not giving them the choices, if we're not leaving that gate open for them to go back and graze ryegrass, if they are just on summer brassica and we don't give them a choice, then preference is irrelevant.
Juddy They don't have a choice. They might eat the weeds around the outside, but essentially they are eating the crop in the middle and we can get some very good performance from them, despite the fact that if we gave them a choice, they wouldn't eat it.
Juddy Initially, and they will get used to that. I think when it comes to mixed pastures and so we've got ryegrass and clover. Obviously clover is higher, but it's only a partial preference, they're not going to completely avoid the ryegrass. And this is where I think from a grazing intake point of view is this idea that if we set stock and allow those animals to go and graze all the clover, right, then what we can do is actually drive down intake simply because the animals are searching for the clover.
Juddy And where we can tighten those up in terms of a rotation and make sure that we're grazing through that. I think that allows us to get a much more consistent intake because we're actually forcing animals to graze through that before they get on to a break.
Allister So opposite to your 70% clover, 30% grass type preference, in the ideal world, open choice. In a set stock situation, they will try to elevate their level of die crop, particularly by using clover as an example in a dominant grass sward. And at a certain point they will expend almost too much energy going looking because they're trying to balance that diet.
Juddy And it's not often that the proportion in the diet. Right. Is actually similar to what's on offer.
Juddy You tend to find if there's 30% clover being offered, the proportion of the diet will be higher because they're seeking. Particularly for sheep cattle, not so much because they are horizon grazers and they've got less ability to select.
Allister That's the issue with sheep though is that they'll have that ideal diet at the start but by the end or actually be a weighted diet more towards pasture on grass. Because they've already eaten what they've wanted to in the first day or two. Hence rotational grazing is probably still one of the better techniques for live weight gain.
Juddy Absolutely. And the other thing that's really important is if we set stock, if you think about and I think Ecotain is a really good example here, if you actually set stock on this because it's got a very fine steam and a big leaf and those animals can basically sit on it in a pasture. What you've giving them the opportunity to keep back, go back and re grazing that even though there's a whole lot of pasture there.
Allister So sometimes when these things disappear out of a general pasture, we don't actually always have any true understanding. It wasn't really until we did some adjacent monocultures of ryegrass at a, I think it was about 70% actually of the area in ryegrass and 30% in plantain that we could actually get the true visibility of the grazing pressure that came onto those individual plants.
Juddy Yeah. So those are adjacent monocultures do give you the opportunity. So they're basically, you know, ryegrass sown on one side of the paddock and the herbs sown on the other. And what that allows you to do is look at the intensity that those animals when they're offered, either as a break the grazing intensity that they put on each of those species. And it is by far much higher in those species like the Ecotain and the clovers where they can actually graze that to a low level and remembering that they want 70% and you've only offered them 30%, the grazing pressure on those is high. Now that's fine if it's over two or three days, but where you set stock and they've got the ability to really camp on those and come back to them.
Allister I think that's why that exercise for us, oh shoot, it was done in the early 2000s, but it was still worthwhile because one, it was very visual. But what it gave an insight as to what was happening to those highly preferred. And, you know, look, not always is our Ecotain preferred, but when it's at lower proportions, and with sheep, you do tend to see it be targeted and you lose visibility of that inside a pasture where grass is dominant and you can't see that. As a layman and a farmer, you can't see what's going on under the canopy of the sward, whereas in the adjacent monoculture was very, very clear. Now we're chiseling this out to 1 to 2 centimetres. Some of the crowns were being eaten literally open up
Allister And that could have been happening out of sight. And then we wake up one day and ask where has our plantain gone is an example.
Juddy Yeah, and to put some numbers around that we could have still had two and a half thousand cover in our ryegrass. But when we looked over at the Ecotain.
Allister It could have been 400.
Juddy Well, you know, it was actually hard to go and measure that with a quadrant because it couldn't pick enough up so it's less than a centimetre high. And so that's what they would be doing in a mixed pasture you wouldn't see it. So I think those adjacent monocultures have been really useful in terms of looking at exactly what is happening in those image pastures. And the way to get around that is simply in terms of reducing the ability of animals to show that preference by those good rotations and not spending a huge amount of time, you know, weeks on end in the same paddock in terms of allowing them to do that.
Allister I think that's a good lead into one of my favourite demos and I think it, you know, it is actually a bit of a summary in its own way because it's also extremely entertaining. So the key really is we do need some big paper bags. You tend to need some not willing volunteers, you tend to spread out the audience and you create a competitive environment where you're trying to manipulate a situation where you're going to demonstrate yourself as an animal, and that is taking your thumb and forefinger together. And that creates the mouth. And unless I'm mistaken, you know, there's a little bit of diversity and the people that will be up for that. But the point is you can't really shift that too much. And the only trigger for actually filling your bag is by using your thumb and forefinger. We have time that at 2 minutes we've made the concession that the person who's the grazing person does get someone to hold the bag so they can hold the rumen and fill the bag. And then what I've done over the past is the best example I had initially was in Australia and a very dried Australian environment and a perennial pasture environment of cocksfoot and in this case cocksfoot and Phalaris. We had both chicory and plantain still actively green, so we had a drying off grass environment with this small oasis of green chicory in plantain, we had two groups, one focused on harvesting grass with the thumb and forefinger and one selectively harvesting the plantain and the chicory. And you give them 2 minutes and probably just to try and create a visual, 2 minutes sounds not that long, but I have not had a situation where someone hasn't complained by about a minute that this is quite hard work. And so you've got the people running around chasing the brown grass, trying to fill a bag as much as they can out of fine upright browning leaves and someone is running around chasing plants at about 5 to 6 inches high that are still green and leafy in quite an upright state. So you just walk straight into one of those with your thumb and forefinger and you've got a whole handful of plantain or chicory and you fill your bag. So that exercise was pretty powerful because what it highlighted at the end of we gave up after a minute and a half it was about 34 degrees. And these guys weren't enjoying the experience and what you came and you opened the bags, you tipped them on the ground, and what you saw is that the people that harvested the grass harvested far less material because one, it was fibrous, lignified, and it was leaves that are upright and fine and they hadn't to get so many more attempts to even get what they did get. And when you looked at what was in the bag, it was brown and not nutritious. Meanwhile, the people that ran around chasing the plantain and the chicory had a bag full of green, high protein, high ME material, and the bag was about three times fuller. And we've done this in New Zealand in a grass environment where you have a mowed area and then you have high covers to demonstrate the bite depth and then the third treatment is the herbs. And when the person is running around on say the 2 to 4 centimetre grass filling a bag, you know, they have lucky to be 20% of the material in their bag after a minute and a half versus the situation where they were presented, say two and a half to three tonnes of dry matter at about probably 20 centimetres a height. They filled a bag and then the people on the herbs nearly filled two bags in the very same time frame. So it's a really visual exercise that you could do with kids. It would be quite an interesting exercise to just demonstrate the effort an animal has to put in to fill a rumen in a day.
Allister Yeah, I think it's a really good demonstration of that and it's one of the first times that you can actually interview while they're doing it, a cow, if you like, to see how hard it is grazing each of those forages. And I agree, the times I've done this, you know, the ryegrass, particularly short ryegrass grazing people don't find that particularly easy. And when you explain to them after, you know, a couple of minutes and I've only got 200 or 300 grams of material and they need to get through to 100 kilos if they're cow, then that really hammers home in terms of what we're expecting of an animal in terms of grazing.
Allister What we present as managers to the animals defines their outcome.
Juddy I think the other and just as a touch point here, the grazing dynamics and the bite size and the bite rate. Although that's relatively old technology, that is actually what some of the new tech in terms of some of these collars actually work on in terms of bite rate and the sound of chewing and regurgitating. In terms of trying to work out whether the cows could eat more or not. So the same process is being used to generate or is a proxy for intake.
Allister For example, rumen health.
Juddy Absolutely, yeah.
Allister The number of times that they chew the cud is a bit of an indicator on the health of their rumen function.
Juddy I think that's a great summary, Allister, in terms of the factors affecting intake, I think my take home points, my key ones here are really around this is a fundamental part of the way animals get forage into them I think as manages we can make it very easy or actually very difficult for them do this. From our point of view, I think we've used this information in terms of systematising or developing different forage systems for animals to graze.
Allister Particularly around finishing and high output systems.
Juddy Yep. And the use of some of the forage herbs and legumes and brassicas in terms of trying to generate that. I think the other really important thing we need to be thinking about is our processing speed, we can make that material last longer or sit for longer in the rumen, depending on some of the forages that we're using. And I think that the other point is that grazing demonstration has been one that highlights significantly what grazing animals are faced with in terms of getting their daily intake.
Allister And what choice means as and how we present our forages to our animals, what impact it has on them.
Juddy Yeah, well, it's a great summary Allister.
Allister Yeah, well done Juddy.
Juddy I should really go feed myself. I think it's time for tea.
Allister Bit of selective grazing Glenn.
Juddy I think there'll be some selective grazing there. So we'll see you next time Allister.
Allister See you later.