Energy from Carbohydrates in a Ruminant Diet

In this episode of the AK Podcast, Mike Donaldson and Grace Thomas discuss the intricacies of ruminant nutrition, focusing on the role of carbohydrates in livestock diets. Grace, an Agri-King Nutritionist from the UK, joins Mike to explore how different carbohydrate sources—such as grains and forages—impact animal health and diet balancing.

Their conversation delves into the importance of processing grains for optimal digestion, managing carbohydrate levels to prevent acidosis, and the role of enzymes in enhancing nutrient availability. They also touch on emerging trends in carbohydrate sources for livestock feed and what the future may hold for ruminant nutrition.

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Transcript

Chris Radke (00:00)
Welcome to the AK podcast where we explore science and nutrition behind livestock care and management with the best and the brightest in the business. I'm your host, Chris Radke, part of the sales team here at Agri-King and with me today and as usual is the Director of Field Services and a member of the Sales Management Team, Mr. Mike Donaldson. Mike, how you doing buddy?

Mike Donaldson (00:20)
Very well, thank you so much. Chris, how you done?

Chris Radke (00:23)
I'm alright I'm alright we're kind of going to some sickness in my family but hopefully get through that quickly it tends to be the season I guess

Mike Donaldson (00:29)
Yeah, I sometimes wonder if you live in a tropical world, what you blame your illnesses on. Because for us, it's winter time. Everyone's going to get colds in the winter. Is there some sort of thing that happens because it's always 80 and sunny? I don't know.

Chris Radke (00:45)
yeah don't i think that's a good thought Mike I don't I don't know maybe they don't get sick as much who knows Alright Mike, who do we have with us and what we talk about today

Mike Donaldson (00:47)
Yeah.
Today, Chris, we're gonna continue the discussion we've started about energy in ruminant diets. If this is your first foray into the Agri-King podcast, you might wanna check out our archives. We've done some work previously talking about how ruminant stomach differs from a monogastric. We've talked about the importance of fiber in a ruminant diet. Today, we're gonna jump in to the role of carbohydrates in ruminant diets.
Joining us, we've got Grace Thomas, our Agri-King Nutritionist from AK Limited in the United Kingdom. Welcome, Grace.

Grace Thomas (01:29)
Hi Mike, nice to see you.

Mike Donaldson (01:31)
Well, it's wonderful to have you join us, Grace. Could you maybe give us a little starting out information, a background, if you will? mean, obviously ruminants in the wild, whether they're deer or bison, mountain goats, really don't eat carbohydrates the way we think of it because they don't have combines and they don't combine corn or maize, as you call it. So what?
What is your starting out? Where do we start talking about carbohydrates and aromid?

Grace Thomas (02:04)
Yeah, so ruminants eat carbohydrates in different forms. There's the form of carbohydrates in fiber. So fiber will break down to a carbohydrate, which is a simple sugar. They just need to access it a different way. So starch and sugars are the typical carbohydrates that we would think of. But there is carbohydrates in fiber, such as hemicellulose and cellulose. So the animals, the ruminants in the wild, still get their carbohydrates, but you just have to work a little bit harder to get this. So that's where the rumen comes in and the microbes break down the carbohydrates to the simple sugars. So starch and sugar will break down quicker, but fibre from the carbohydrate, so pasture and hayes and alfalfas have carbohydrates, but in a different form. So that's where they get their carbohydrates from.

Mike Donaldson (02:37)
Okay.
Well, so, and if you're in the United States, listen to this, maybe there's some things you already know about ruminants in other parts of the world, maybe there's some things you don't, especially in Ireland, but really a lot of the United Kingdom, a much higher percent of the farms utilize pasture than some areas of the states do. So if you're saying there's pectins and sugars and forage, how is that impacted by how good the pasture is? What is the, I do you see a dramatic difference in how you're balancing diets because of the quality of the pasture?

Grace Thomas (03:37)
Yes. Yes. So spring pasture would be the best quality. So at the start of April onwards would be the high sugar, the low fibre. So the energy in the carbohydrates there would be sugar form. As it gets later in the year when the pasture is trying to seed, the fibre goes up. So there's hemicellulose and cellulose, but the lignin binds it so it's not as available. And then it's...the sugars will drop down and then later on in the year, usually around August, we'll get a spring flush again, sugar flush again. So that's when the sugar will tend to go up again in the pasture. And then if you cut your grass at that time of year to make silage, it should be in line with that.

Mike Donaldson (04:23)
it would hold that same higher level.

Grace Thomas (04:25)
It hold the same height. So silage cut from grass made in spring will be higher in sugar and lower in fibre than silage cut from grass made in July. And pectin will be the main sugar in our grasses over here.

Mike Donaldson (04:37)
Okay.
So when you're balancing diets, and let's start with your world and we'll move to the United States for the correlation.
What are the things that you typically use as an added source of carbohydrate? I guess I'm going to think in terms of grain. that that source? Yeah.

Grace Thomas (05:03)
Yes, yes, great. Yes, so we would tend to use wheat and barley over here as our main grain sources. Maize is becoming more popular, so corn is becoming a little bit more popular, but not many parts of the UK or Ireland can grow maize. So wheat and barley would be the most popular carbohydrate source we have. Wheat and barley are actually more fiery, more readily available than maize. So we do have to be careful.
We would have maize silage in our diets, but about 40% of diets maybe have maize, the rest would be all grass-based. So when you look at a limited diet versus an American diet or a UK diet, we would have a starch of about 12%, 15% maybe. But if we were to go to a 20% starch diet with only small grains like wheat and barley, it would be too spicy or it would not work well in the rumen.

Mike Donaldson (05:59)
just hit too you said fiery it would just hit too fast okay

Grace Thomas (06:00)
too fiery. Yes, it is too fast because hwys is quite fiery. Wheat is firier than barley and then maize is a bit slower digestives So our diets would be lower in the start.

Mike Donaldson (06:09)
Okay, so if you find yourself needing more energy from carbohydrates, what can you use past wheat or barley in those situations?

Grace Thomas (06:23)
with holes in beef pulp, which would be a carbohydrate in the form of pectins. Okay, that's where we would use a lot of holes in beef pulp to balance up to wheat and barley.

Mike Donaldson (06:28)
Okay.

So, and we did talk about some of that with Dr. Schauff and I sometimes think of them as less energy from fiber. What you're correcting me to is the observation, yes, but it actually is not only fiber. There are pectins, there are sugars in those feeds as well.

Grace Thomas (06:55)
Yes, the sugars in those feeds as well. Yeah, they have the pectin, which is a soluble fibre that acts, that will create acetate in the rumen, which goes from, which does go on to create milk fat. So there is carbohydrates in those feeds as well.

Mike Donaldson (07:11)
What has your, now I'm just being curious, what has your people interested in feeding more maize or corn for you United States people, what has them more interested in maize when for many, years wheat and barley have been sufficient?

Grace Thomas (07:32)
balance because wheat and barley are quick in the rumen, maize is slower released so you just you're going to balance with the slower release proteins that's in the diet. it's always good to have at least two starch sources in a diet. So it's the fiery stuff, the quick in and then the slower. then again maize forages which contain the maize carbohydrates or slower release as well and the maize and grass work very well together.
It's like the ideal dice. The grass comes with the high sugars, the high fibre, the high protein and the maize lower protein, higher starch balances it up perfect.

Mike Donaldson (08:11)
How does the way that carbohydrate grain, the wheat, the barley, the maize, how does the way it is processed impact how you want to use it? What would you be asking someone to do as they grind, whatever they do to prepare that grain to be fed?

Grace Thomas (08:37)
So the more the grain has a kernel which stops the access for the bugs to release. So the more you crack that kernel, process the grain, the more available and highly digestible it is. So if you cook or flake or steam flake, that's already started the process of digestion so the bugs can get quicker. If you crack it versus finely grind this, just cracking is less available than finely grind stuff.

You're kind of starting the process before it gets into the rumen.

Mike Donaldson (09:09)
What's the most common way you're processing wheat or barley?

Grace Thomas (09:15)
Rolling is probably the most, so just roll it would be. We do crimping a good bit, so crimp it would be like a high moisture corn, you take it when it's not fully mature and it goes in a pit, but we're limited to space on the farms. Also rodents like it, so it's hard to keep us. It's tasty. So crimp would be an ideal way to process this, it's, and again, it's getting the contractors cutting on time. Rolling would be very common. Rolling.

Mike Donaldson (09:17)
Okay, okay.

Yeah.

Grace Thomas (09:45)
just a dry roller.

Mike Donaldson (09:47)
And you mentioned flaking. Is that something that you would do with maize? And only maize?

Grace Thomas (09:51)
Yes, yes, it tends to be flake. Sometimes we get toasted flake wheat or barley but I think that's processed in a mill rather than on farm. Some farms have their own rollers for wheat and barley.

Mike Donaldson (10:01)
Okay.
Now, to get you to maybe stretch a little bit, and we won't give out your phone number, nobody from Kansas is gonna call you, I promise. So, when you look at the diets in the United States, where we at times feed corn, and then we feed more corn, and then we feed more corn, do you see, you mentioned getting at least two carbohydrate sources.
If you look at our diets with a critical eye, would something like barley have a role in how we feed cows over here?

Grace Thomas (10:41)
Maybe, but you might not have the ready soluble protein that we have in the grass silage that needs that energy straight away. you might be able to get your different forms of starches by processing your maize in different ways. So one might be more readily available. That would provide the different energy at different times.

Mike Donaldson (10:57)
Okay.

I know that, I know some of the things Agri-King, well, I think things I think Agri-King does to get accurate balancing the proper use of carbohydrates. What are some of the things that you would see in a herd of cows if carbohydrates are being fed at too high a level?

Grace Thomas (11:25)
the most thing would be acidosis because starch usually breaks down to propionate and that would then go for energy but if you have too much starch or it's added too quickly to the dice because you don't have the room of microbes to utilise it straight away you can get acidosis. get a build up of lactic acid rather than the propionate so that's where you start to get acidosis and then you get animals that are off feed

Mike Donaldson (11:28)
Okay.
Mm-hmm.

Grace Thomas (11:55)
you can also get a bit of high and good fermentation so the grain is actually getting fermented in the high and guts and then you get bubbly manure issues and then sore feet so that's where if it's it's too quickly the starch or the cows or the animals not used to it.

Mike Donaldson (12:04)
Okay.
All right. But you mentioned before the concept of being sure you match up how quickly available the protein is and how quickly available the carbohydrates would be. What are the one or two things that you watch in a diet to see that that balance is being achieved?

Grace Thomas (12:32)
So the first thing I look at would be SP to RDC, so the rumen degradable carbohydrates to the soluble protein in the dyes. So then if you've got the protein to energy balance, you should have a healthy rumen. You're not feeding excess protein, because excess protein is costly, and also it can cause issues in the animal with high milk urea, poor fertility. And also if you're not feeding too much energy, because then the energy is going to be wasted, there's not going to be the rumen bugs.

Mike Donaldson (12:50)
Mm-hmm.

Grace Thomas (13:00)
to use it. that's the main thing I'd look at with SP to RDC to balance. When I look at the dyes I like two different forms of starch as well.

Mike Donaldson (13:09)
Okay. Now there's a little bit of difference between some of the things that products that are approved, aggregating products that are approved for use in the States. And you don't always get the full list of those things over in your world. But you work with our nutritionists here. I think you do a great job doing nutrition work in the United States, if that's where we could get you to move, but not looking to do that anyways. Does what?
What does Agri-King's enzyme offerings do, and we're mostly talking about there, is we also feed beef. What do you see as being some of the advantages from the enzyme program that Agri-King offers to continue to fine tune that carbohydrate digestion?

Grace Thomas (13:56)
So the enzymes will make, start the process of digestion for the ruminant. So it makes what they are more available. So we have our enzymes that work in forages, such as our RUMAX in the UK. So that will start the breakdown before the ruminant gets it. So it's speeding up that process for digestion and helping the animal along to get the energy
Then we've got our silage additive enzymes as well, which start to process before the animal eats us in our Silo-King. And then in the UK, we've got Maximizer is our main enzyme for our beef, which would work on the starch and sugars before the animal gets us. So it's just providing the energy in the rumen quicker to the animal and processing that grain, breaking the bonds to get the microbes access to us to get energy out of carbohydrates.

Mike Donaldson (14:50)
So sort of an additional, just an additional help to that animal to get things broken down and used more completely.

Grace Thomas (14:59)
Yes, making the animal utilise it better. if there is an issue with corn not being cracked correctly or the rolling not working or the fibre is little bit too tough, it just starts that process. Before the animal can utilise it, it speeds it up a little.

Mike Donaldson (15:10)
Mm-hmm.
Okay. What, what, what do you see as the role in something like molasses, liquid molasses or dry, suppose, but mostly liquid something, something that literally, if you put your finger in it and taste it, it would taste like sugar to you. Corn, corn, barley, wheat, none of that really tastes like sugar to me very quickly. But I know that these direct sources of sugar.
Are often used to finish tuning out the carbohydrates in diet. How do you use those?

Grace Thomas (15:54)
Yes, so the sugars in a diet, I do think people underfeed sugar. They like molasses, but because it goes in a tank and it gets in the cold weather, it's hard to use. And we don't get much dried molasses in the UK. even I would try to molasses in every diet apart from a pasture diet They've got their fructans. They don't need the sugar. So molasses is, or the sugars, act different to starch in the rumen. They create.
Butyrate which is quicker. It goes on to, it's not like lactic acid. It doesn't reduce the pH as much. It's quick, it's faster acting in the rumen. So doesn't have that, we don't get that acid drop. Apart from that, so you can feed it with a high starch because you're not going to get that high acid drop. You're not going to get lactic acid that can lead to acidosis.

Mike Donaldson (16:52)
Okay. So, so while from a purely making silage standpoint, we try to avoid creating butyric acid in silage. This is a desirable thing. Once it's in the rumen of a cow that she is going to take sugar. Did you see, say, did you say, say the word you use? wasn't butyric acid butyrate. There you go. Okay.

Grace Thomas (17:08)
Yes.
Butyrate, yeah, creates butyrate, and she will take, she will create ketone bodies with this, which then is an energy source to the animal. And also some ketone bodies go on to the mammary gland and go for milk fat. So it's a different pathway to starch.

Mike Donaldson (17:21)
Okay.
Okay, that's fascinating. Do you have any, you've given me a lot to think about at least, any final thoughts on what you've seen, what do you think the future's going to be? Are there going to be some new carbohydrate sources or continued fine tuning? Where do you think we're headed with this?

Grace Thomas (17:57)
Not sure, I think we'll get more carbohydrate sources from byproducts. So I think they'll be growing as the food industry grows. There'll be more byproducts for the feed industry. So like the biscuit meals will continue to come, the cookie meals, the sweet mixes. Maybe there will be our difference. I'm not sure with grains. People go through phases. know in the UK and Ireland where we're feeding rye and triticale and then the...there are different forms of starch grains, but then they seem to grow out of fashion and then they're gone after two years. So I think maybe for us, it would be more byproducts growing up and maybe more people growing maize over here to balance, but maize as a forage. But I do see more people crimping maize, like a high moisture corn, but it's not always successful because it can have toxins in it a different way. But that is becoming more popular over here, so I think it's going to be fine tuned.

Mike Donaldson (18:45)
Okay.

Grace Thomas (18:55)
bit more at a.

Mike Donaldson (18:55)
And probably a change, a slow change in hybrids that starts to reflect your growing season with a corn that can do well in that situation.

Grace Thomas (19:02)
That's exactly, yes, that we can get it because the high moisture corn is cut so late in the year to be fully mature. It's just not it's not as viable as it should be. But I think we're getting there. So it's there is probably people working on this out there.

Mike Donaldson (19:16)
That's interesting. Well, Grace, I really appreciate you joining us today. Chris, what'd you learn?

Chris Radke (19:25)
hey uh... my big takeaway is the like what Graces talk about the of specific uh... i guess grains tour area as opposed to like their diets for cows can be completely different though we have a right here i don't know you think about that stuff that i ever think about because the cow I thought so but you cater to that animal to that area so that's i think it's fascinating uh... if you like what you heard if you like what we talked about hit us up on any of our socials if you have anything you'd like us to talk about you can emails podcast@agriking.com. Thank you so much, Grace. Thank you so much, Mike, for your time and have a wonderful day.

Mike Donaldson (20:02)
Thank you both so much. Appreciate it. Thank you, Grace.

Grace Thomas (20:05)
Thank you.