Energy from Fiber in a Ruminant Diet

In this episode of the AK Podcast, Mike Donaldson and Dr. Dan Schauff discuss the critical role of nutrition in livestock management, focusing on the importance of energy and fiber in ruminant diets. They elaborate on the energy needs of dairy cows, the significance of fiber, and the impact of forage quality on overall animal health and production. The conversation also touches on non-forage fiber sources and the evolution of nutritional strategies in livestock care.

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Transcript

Chris Radke (00:02)
Welcome to the AK Podcast, where we explore science and nutrition behind livestock care and management, 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, 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 (00:22)
Very well Chris, how's everything going in your world?

Chris Radke (00:25)
It's a little dreary outside, I hope to warm things up with this wonderful conversation with Dr. Schauff. So, you want to introduce him?

Mike Donaldson (00:33)
Absolutely. Well Chris, there are a lot of different categories of nutrients when we're feeding ruminants. Often protein gets all the attention. I think largely because on a lot of farms that's one of the biggest out-of-pocket expenses when it comes to feeding cattle. A lot of protein is bought instead of raised. But if you were to look at a diet more money is spent on meeting an animal's energy needs than on their protein needs. It's just that a lot of that energy, especially if someone's growing their own corn grain, a lot of that energy comes off of their own farm and it somehow feels differently. Now we did a previous podcast about the rumen, about the four compartments in a ruminant's stomach, and we want to start going a little deeper into the energy part of nutrition, but to begin we want to deal with the aspect of fiber meeting a big part of those energy needs. And to do that today we have Dr. Dan Schauff from the Nutrition Department at Agri-King. Dan's actually one of our longest tenured nutritionists at Agri-King and he is going to take us through the role fiber can play in meeting a ruminant's energy needs. So Dr. Shah, thank you so much for joining us today.

Dr Dan Schauff (02:05)
Well, it's a pleasure to be here, Mike.

Mike Donaldson (02:09)
So, feel free to disagree with me if you like, but what makes energy such an important part of nutrition that it's the one we want to address first when we start breaking this down?

Dr Dan Schauff (02:13)
All right.
Well, three things come to mind. First off, energy is really difficult to define what energy is. When you talk about protein, you're talking about carbohydrates, they're made up of amino acids, and fat is made up of fatty acids, and you can analyze it, and you can actually see it. But when energy is hard to define, it's the potential to do work.  We don't actually measure it directly. When we look at energy in a feed or something, we're actually looking at heat production, which is indirect. But energy is very important. It's what moves things metabolically in the body of your urine eyes system. And so the combustion of like things like carbohydrates and to a certain extent, protein and fat is what drives metabolic reactions in the body. Things like we need energy for maintenance, right? So for things like digestion, absorption requires energy that's produced from the breakdown of carbohydrates and fats and energy yielding substrates, respiratory function, immune function for that animal to move around to use its muscles that needs energy, which is part of that maintenance requirement. And then there's a huge requirement for like growth and reproduction. And milk production. So energy is just critical for life and critical for efficient production. Just to kind of give you an idea of how much energy a lactating dairy cow requires, you and I as adult males, we require about 2,000 kcals a day to meet our energy requirements for us to function, to live. If you take a 1600 pound dairy cow producing 120 pounds of milk and four plus milk fat and so forth, she requires about 12,000 kcal of energy each day just for maintenance. Just to digest feed, to move around, chew or cut, breathe, for heart beating and so forth. That's like six times what you and I need for energy. And then another 43,000 calories just for the milk production. So she requires 55,000 kcal a day, that 120 pound. So just the requirement is just tremendous. And of course fiber and different things are going to be part of that meeting those energy requirements.

Mike Donaldson (04:49)
So lactating dairy cow needs around the same amount of energy a day as the starting 11 people on a football team then. If I'm doing my math right, 2000, okay, wow.

Dr Dan Schauff (05:01)
You're right. It's, yep.
Yeah. It's a tremendous amount of energy. Those dairy cows are just awesome machines that God made. It's just awesome.

Mike Donaldson (05:13)
Well, you mentioned the different, you know, there's some different types of fiber. I'm sorry, there's some different types of energy. We want to deal with fiber today because that is the aspect that a monogastric, ourselves, pigs, chickens, don't really get a great deal of nutrient and fiber is important, but we don't get a great deal of nutrition out of it.

Dr Dan Schauff (05:38)
Mm-hmm. Mm-hmm.

Mike Donaldson (05:43)
From your perspective, and maybe this goes into even starting to talk about the difference between the measurement of fiber ADF versus NDF, what are the quote unquote best types of fiber in a dairy cow's diet? What are we gonna get the most bang for our buck out of?

Dr Dan Schauff (06:01)
Okay.
Sure, So maybe I'll just talk a little bit about what fiber is. ADF and NDF stands for Acid-Detergent Fiber, Neutral Detergent Fiber. Those are lab measurements that we've used for decades. And it's basically a measurement of the plant cell wall, other known as fiber. So NDF encompasses what fiber is. And as you pointed out, Mike, non-ruminants, you and I, don't produce digestive enzymes to break down the fiber components. It's the bacteria that are in the rumen or the lower gut of the animal. Of course, we have a little bit of hind gut bacteria as humans too, so we have maybe a limited ability, but we don't have any natural enzymes to break down fiber, the components of fiber. It requires fiber digesting bacteria in the rumen and in their lower gut in order to utilize it. So basically what in regards to what are some of important things in NDF that's important for the dairy cow, you got about four or five different components. Cellulose is one of the components of fiber. It's probably the majority of the fiber that's in NDF and it has a certain degree by itself. It has a pretty decent degree of digestibility. For example, the fuzz on cottonseed is almost a 100% cellulose. The cotton clothes that we have is 100% cellulose.
And it's made up of glucose units hooked together, but we don't have the ability to break it down. That's why we need that. And then the second aspect of NDF is lignin. And lignin, kind of refer to lignin as kind of the rebar in cement. So the more rebar you put in cement, the stronger that cement wall is. And the same thing goes in forages. The more lignin, that's in those forages the stronger that plant is the problem is lignin is not very digestible and it makes the cellulose less digestible because it encrusts into the cellulose so it's a component that makes it less digestible and basically as the plant gets more gets more mature lignin increases digestibility goes down and so that's why the we want to try to avoid very mature forages because that's going to reduce digestibility now the other
other things that are, there's two other major components in NDF. One is hemicellulose. That's made up of five carbon sugars, xylose and arabinose. They're pretty digestible by themselves as long as they're not encrusted with lignin. And then pectin, which is a polysaccharide, a glycolic acid, and it's very digestible, about 90%. And basically in a young plant,
The pectin is pretty high. We've got some pretty digestible cellulose. We've got pretty digestible hemicellulose. The lignin is not real high. And so we have good digestibility. But as the plant matures, the lignin goes up, the pectin goes down, and our digestibility and our energy that we can get from that forage goes down.

Mike Donaldson (09:18)
I know across the country where you farm there can be vastly different approaches to where we're going to get good quality fiber. If you're in California you may be feeding a lot of byproduct, almond hulls, pumice, like that. If you're in Florida with that growing season things are a little different. The Midwest is a touch different again.
But I think universally, the first place we're going to look at fiber as a great source of nutrition will be from forages. So you're saying that the younger a plant is, the less lignin it's going to have. Is the example of the best you could get then a cow?

Dr Dan Schauff (09:56)
Mm-hmm.

Mike Donaldson (10:16)
being out on fairly young pasture? mean, would that be the gold standard of quality fiber from a forage?

Dr Dan Schauff (10:24)
Yes, mean immature, I mean you can get some really young spring pasture can be quite digestible and it's good. It's not going to provide everything that the cow needs so you're still going to need to feed some things around it to complement those forages. But yeah, young pasture, immature alfalfa can be very, very digestible and provide a good portion of the energy for that animal needs.

Mike Donaldson (10:52)
When we're feeding a cow, and there's a number of things that we've got to be aware of, I understand, but is the, what kind of a transition period do we need to allow for if we're gonna, if we're gonna go, if we have to make a major change in forage type, how long does it take the room to adjust to that kind of a switch in forage or forage quality?

Dr Dan Schauff (11:19)
Well, it kind of depends on the degree of the difference in the forages and the feeds. I mean, if there's a dramatic change going from really good quality to really poor quality, then it could take a couple of weeks for that animal's rumen microbes to adjust to it. And then even then, we're going to have to feed some more commodities and things around it to make up for what we don't have in that poor quality forages.

Mike Donaldson (11:48)
I do think Agri-King focuses awfully hard on helping someone get good quality forages and then getting the most use out of it. There seems to also be in the industry the opinion, well we've got grain, we can take any quality forage and put enough nutrients in it to get the production, the components that a farm might be looking for. What do you see as the weakness in that approach where we don't emphasize forage quality and we just essentially feed them barely better than straw, but add enough grain to get the nutrients that she needs.

Dr Dan Schauff (12:28)
Okay, well a couple things come to mind. Number one, and you might have alluded to it earlier, that whenever we're feeding poor to average quality forages, in order to meet that 55,000 kcal, right, if we don't get it from the forages, then we have to get it from the grains, we'll get it from commodities, from protein sources, from fat sources, and so forth. And so generally speaking, the ration costs are going to be greater. So that's one thing.
Not always, but a lot of times the cost of that ration is going to be greater when we have poor quality forages versus much better quality forages because we don't have to feed as much. And especially purchase feed costs, you know, the cost for protein, the cost for protected fat and other commodities and stuff. So the ration costs more typically with lesser quality forage. So that's one argument against it. The second argument is that you just oftentimes can't quite duplicate the level of performance with poor quality forages and making up for it was you know like soy hulls and corn and protein sources and fat and so forth. can you can get more milk production versus not making the adjustments at all but you just can't duplicate the same level of performance the same level of production the same level of component efficiency with poor quality forages that you can with good quality forages. And some of the reasons why that is, is that when you're feeding, you know, less quality forages, you got a lot of times we have to push the grain levels higher to meet energy requirements, as I mentioned. The problem with feeding more more starch to meet the requirement is that after a meal, the cow's, that starch is being fermented so quickly.
That it's producing acids very quickly and it drops the pH. The fiber bugs do not like low rumen pH, it's much below 6 for a very long period of time, it's going to knock back your cellulite population. So then you're actually going to reduce even further to the adjustability of the fiber. So what fiber is there is less adjustable, but then when we add corn it tends to put pressure on that whole buffering system and so they actually get less out of the forages and so then they don't get as much.
It also makes it hard to maintain milk fat, that sort of thing. And the other thing too is when the animals are exposed to long bouts or chronic situations of feeding a lot of corn to try to balance the diet. And so that puts pressure on that whole buffering system. Eventually it's going to have a negative effect on the rumen epithelium, the rumen wall, on the intestinal wall. And that can cause...
negative effects on absorption. So you got to break things down, we got things absorbed. And if you damage the rumen wall, you damage the intestinal wall, then our absorption deficiency goes on. So all those things are going to prevent us from getting that performance. Plus, we're going to have probably more health problems. Then there's going to be expenses incurred with what that you know, and then you know, there's a lot of talk in recently recent years about leaky gut syndrome, right? When you have any kind of inflammation or stress, whether it be mycotoxins, whether it feeding too much corn, you get what you call a leaky gut. where bacteria then can infiltrate into the bloodstream and then the cow's response is inflammation. And that immune system is activated and it requires a lot of energy for that to fight that immune challenge. There's been studies that have been done where they estimate that whenever a cow is trying to, there's an inflammation event could be heat stress, be caused by mycotoxins, could be caused by too much starch with a little bit acidosis, that that steals about thousand grams of glucose a day that would have went for milk production, but it increases the maintenance requirement because the immune system is activated and it's a hog of glucose. And so then that takes energy away for milk production. That could be five to 10 pounds of milk that we don't get because of all this chronic infection. And then that, of course, that leads to...poor animal health and longevity goes down the tubes. So there's so many things, probably covered too many things.

Mike Donaldson (16:53)
No, but you are putting a nice exclamation point on why we started with fiber because, you know, it's easy to forget what an important foundation that sets for everything else. So I've got a farm and as we record this, it's the middle of winter, so I've got the forages that I've got. Great quality, average quality, whatever it is that I have. You mentioned earlier.

Dr Dan Schauff (16:58)
Hmm?

Mike Donaldson (17:21)
That there are some non-forage sources of fiber. And you also mentioned the danger of trying to overuse starch to get that energy that the cow isn't getting from forage. First, what are some, you mentioned soy hulls, but go back again please. List what some of the common good sources of fiber are from non-forage. And then secondly, we'll talk about working them in and how to use them, but not overuse them. But what are some of the things that you typically see go across your desk as other sources of fiber in a diet?

Dr Dan Schauff (18:06)
Sure, so especially when we're dealing with average or lesser fiber digesting forages and stuff, like as I mentioned before, there's only so much starch you can feed before you start having some problems with rumen health. And so one of the roles of a non-forage fiber source is to provide a non-starch source of energy. And that provides digestible starch. I mentioned that immature forages tend to be higher in pectin, especially alfalfa, which is very digestible. And things like citrus pulp, if you're down south, or soy hulls in the Midwest, usually are pretty good sources of pectin, which is very digestible. So it can kind of complement a poor quality forage, right? So it provides, plus the NDF is very digestible too. There's very little lignin in it. there's very little that's going to prevent it from being digested in the room. And so they can be a good way of getting energy in there if we don't quite have it from the forages. Now, the problem is we can only feed so much soy holes because even though it's a very good source of digestible fiber, it's a very poor source of effective fiber. And so, you you still need that forage there to form a good rumen mat to stimulate head chewing and buffering and all that kind of stuff. That's important for digestibility, but it can be there. So citrus pulp soy holes, I think of them as a very adjustable fiber source. Out in California, almond holes.
They can be a digestible fiber source. They actually are fairly effective fiber source because they have some length to it. So, but it's usually not quite as the quality of fiber as like soy holes and citrus bulk would provide. Another good source of non-forged fiber is cottonseed. And it's, like I said, the fuzz is pretty much all cellulose and it's got a you know it's not as probably digestible fiber as soy hulls but it's got a decent amount of fiber digestibility and it also has some degree of effective fiber too so it's when you're when we need some digestible fiber plus we also need to maybe stretch our forage supply a little bit because we're short on inventory we can use cottonseed and soy hulls to a certain extent to extend our forages a little bit the other benefit of cottonseed is also got protein has also got oil and fat, so it's a really good all around. It provides protein, fat, and fiber. It's a nice product to be used. Whether it's good quality forages or even poor quality forages, cottonseed is a nice fit there because it provides a lot of different things, protein, energy, and digestible fiber. And then sometimes in the Midwest, distillers, corn gluten feed is readily available and economical. It's not what I would call an ultimate fiber source, but it has some decent fiber digestibility too. So we can use distillers, can use corn gluten feed, that sort of thing to kind of fill in if we're limited either on supply of forage or we're limited on quality forage.

Mike Donaldson (21:13)
So some of those feeds being able to bring in more than one nutrient and affect the balance of the ration. I've seen, in fact we have a client in the Thumb of Michigan right now that got an incredible deal on wet beet pulp. And you guys have gone ahead and set a ration up that probably walks that a little closer to the line. But...

Dr Dan Schauff (21:32)
Mm-hmm.

Mike Donaldson (21:41)
He's got a great supply of forages, but while he can get this beet pulp, he is going to try to maximize the use of it strictly from a dollars and cents standpoint.
What are the, yeah but you gotta watch if you're gonna do this type of things that can come in when you start trying to force a non-forage source of fiber in because it's a good buy.

Dr Dan Schauff (22:09)
Well, probably the biggest thing, I mean, and I should mention that beet pulp is also an excellent source of pectin. It's very much like, I failed to mention that, so I'm glad you brought that up. Beet pulp is a tremendous, you know, it's good source of pectin, very digestible fiber. It can be excellent in that standpoint. The biggest limitation, as I mentioned before, with soy hulls and beet pulp and citrus pulp is that they're not a very effective fiber source. So a dairy cow requires a certain amount of effective fiber. So that's why we have that Penn State separator where have the top sieve. catches fiber that's like three quarters to an inch in length. You need a certain amount of that in the diet and some of these soy holes, beet pulp are not going to provide that. And the reason why that's important because if we have, we don't need too much, but just enough, maybe 5 % of the fiber being in that long length. It stimulates cut chewing and that cut chewing produces saliva which produces buffering and that helps to balance the rumen. So that's an important aspect of it and things like soy holes and things like citrus pulp or beet pulp are not going to provide that cut chewing scratch factor. The other thing is you need a certain amount of length. need an inch, you maybe need a half inch a third of an inch forged particles to form a rumen mat. We talk about it a lot of times they talk about a rumen mat and that can be hard to describe but it's kind of like a net that holds the finer particles in the rumen so they can get digested like the corn, the soybean meal, that kind of stuff. Otherwise if we didn't have that mat there things would flow out of the rumen before we want it to and we lose digestibility and that sort of thing. And so if we just add more more soy holes that rumen mat can get soft and we get too fast passage rate and we have problems with maybe butter fat sometimes. We have lack of cut chewing, poor digestibility and that sort of thing. So there's a limit on how much you can feed of that.

Mike Donaldson (24:15)
Okay.

Any closing thoughts on?
How you've seen the importance of fiber shift maybe in your experiences as a nutritionist? Are we looking at some things differently than we did 10 or 15 years ago?

Dr Dan Schauff (24:37)
I don't know. guess when I first came to Azure King, we oftentimes emphasize the importance of forage quality to, know, whenever we can feed cows more good quality forages, we don't have to rely on as much commodities. So it lowers feed costs. That's kind of been a thing that we have promoted for a number of years. And I think it's even more important today than it was even 30 years ago when I first came to Agri-King and the being and the reason I say that is that in the US we don't consume a lot of fluid milk but we consume a lot of solids. We consume a lot of cheese, we consume a lot of things like yogurt and that sort of thing and so the value of milk fat and that sort of thing is really and components have really been very very important and the genetics are moving more towards components.
And so it's going to be more and more important to have a good foundation of good quality forages because when we get a fermentation, a breakdown of some good quality forages, we get things like acetate and butyrate produced. Those are crucial for milk fatty acids. If we're going to realize the genetic potential of that dairy cow, we want to make sure we have a good foundation of good quality forages, digestible forages. And if we have good digestible forages, we don't have to feed as much starch. So we have a healthier rumen and then we have better fiber digestibility because we have a healthier room and then we got more milk fat. just kind of feeds on that. And then we still have to feed the animals some grain and still need to feed them things like sugars and stuff and fat and all those things are still important to that. the better the quality of the forage, we don't have to rely as much on that. And we're going to more more apt to realize the full genetic. capability of that dairy cow that we're feeding today to try to really feed for pounds of components, milk fat, milk protein, and those sorts of things. And I think it's going to be very important. The other thing is I think we're learning more and more all the time is that the benefits of a healthy microbiome, so microbiome, that's all the bacteria and stuff that are in the room and in the gut of the animal and one of the things that we're finding is the microbiome has a huge impact on the health of the rumen wall, health of the intestinal wall, the health of the animal. And one of the things that, that I went to a conference a few months ago, it was a ruminant conference in Chicago and a rumen microbiologist by name of Todd Callaway from the University of Georgia. He kind of made a comment that kind of stuck with me and he was saying basically a healthy microbiome and forage quality is very important to that.  Healthy microbiome is one of the best shock absorbers against stress. so cows have to undergo all kinds of stress in today's environment. When you talk about, like you mentioned before, feed changes causes stress. If you have a healthy microbiome, those cows are going to go through that feed change a lot smoother. If you've got heat stress, if you have a healthy microbiome, they're going to endure the heat stress better. Microtoxins, that's something that we deal with more and more.  That's gonna, and if we have a healthy microbiome, that's gonna do, and then of course, the big thing right now is bird flu, right? And we're finding out that the cows that have the healthier cows to start with, healthy rumens, they tend to have less issues with the bird flu. The duration of it is shorter in herds. So they're just, and then if we have a foundation of a healthy rumen, it's just gonna mean that we're gonna have a cow that's gonna stay in the herd that much longer. We don't have to call her before we want to. more production out of her and melt component efficiency.

Mike Donaldson (28:30)
It sounds like since they, it sounds like it's as simple as saying, they are ruminants. They can digest fiber. Let's, let's embrace that and get the most out of it that we can. And a lot of other things just go along with what, with that.

Dr Dan Schauff (28:39)
Yeah, sure.
Yep, we just need to complement that really good quality forages to optimize things.

Mike Donaldson (28:49)
Dan, thank you so much for being with us today. Very illuminating. Chris, what'd learn?

Chris Radke (28:58)
Hey, I learned that number 55,000. That is a huge number. And I think Mike referenced a football team. Just your whole talk about like, as a football team, they can't eat just junk food if they're going to perform properly. So thank you, Dr. Schauff for illuminating that for us. If you like what you heard, you like what you were talking about, hit us up on any of our socials. If you have any questions or concerns or a thing you'd like to, something you'd like to talk about us more, talk us about more.

Dr Dan Schauff (29:02)
You're welcome.

Chris Radke (29:28)
You can send us an email at podcast@agarking.com. All right, Dr. Schauff, Mike, thank you so much.

Dr Dan Schauff (29:38)
You're very welcome. Thank you.

Mike Donaldson (29:40)
Thank you guys, appreciate it.