Effective fiber inclusion in beef cattle diets
Print
EmailFebruary 26, 2025
More Info
Fiber inclusion and the effectiveness of fiber in the diet plays an integral role in the digestibility of the diet being fed, which ultimately affects energy production and gut health of the animal.
The 2025 MI Ag Ideas to Grow With conference was held virtually, February 24 - March 7, 2024. This two-week program encompassed many aspects of the agricultural industry and offered a full array of educational sessions for farmers and homeowners interested in food production and other agricultural endeavors. More information can be found at: https://www.canr.msu.edu/miagideas/.
Video Transcript
Welcome to the MI Ag Ideas to Grow with Virtual Conference, and I'm glad to have you here. My name is Jerad Jaborek. I'm the beef feedlot educator with Michigan State University Extension. I'm based out of Sanilac County over in the thumb, cover statewide responsibilities in terms of cattle feeding. So today, I'll be talking to you guys about effective fiber inclusion in beef cattle diets. But before we get started, I have a couple of slides to share with you. One of them is the beginning Farmer resource and decision making guide. We'd like to get some feedback on the content that goes into this guide. We have a QR code here on the screen that you should be able to see. If you'd like to offer some feedback, go ahead and snap a picture of that so that it directs you to the survey and if you could provide some feedback that is greatly appreciated. I'll give you a moment to collect that if you're interested. Next, we'd like to take a quick moment to thank our sponsors, AgriStrategies, LLC. Due to their support, we're actually able to offer this event for no charge for our participants, so thank you to them. Next, before we begin the session, you can see the link that I posted the link I posted in the chat for everyone there is if you're interested in learning more about Farm Stress. We have a quick video that we're going to play regarding Farm Stress for you all to watch. Farming can be tough. You've got uncontrollable weather, pests, fluctuating markets. It can be enough to make anyone feel stressed. But what happens when the stress becomes too much when it starts to affect your health and well being? That's where the MSU Farm Stress Project comes in. Our mission is simple to help farmers manage stress and improve their health. Team of experts work closely with farmers to provide trainings, counseling, and other resources. We focus on areas like financial management and stress management and building resilient communities. Our goal is to help farmers reduce stress and anxiety, build skills and resources that they need to thrive. Because when our farmers are happier and healthier, our communities are happier and healthier. Join us in our mission to manage farm stress and improve behavioral health. Contact us today to learn more. So like I said, I'm Jerad Jaborek and we're going to be talking about effective fiber inclusion in beef cattle or feedlot diets. First, let's talk a little bit about what fiber is. Essentially, what we're going to start with is talking about carbohydrates. Fiber, it's a type of carbohydrate that we use to provide energy in our feedlot diets. Essentially, that's what our finishing rations are for in our beef cattle feedlot diets is to add enough energy where we're promoting a optimal growth, if you will, and start to deposit some of that energy, store it as fat for improved carcass quality. On the topic of carbohydrates, carbs are going to be the primary energy source in our cattle diets. They can be divided into two types of categories. One is going to be our non fiber carbohydrates. Sometimes you'll see this acronym of NFC. The other is going to be your neutral detergent fiber, also abbreviated as NDF. So for your non fiber carbohydrates, that category is going to include your organic acids, your water soluble carbs, or you can think of the sugars that are inside in a plant. It's going to be made up of starch and soluble fiber. Your more digestive components, if you will. Then the neutral detergent fiber is going to be made up of your hemicellulose, cellulose and lignin. Along with the abbreviation NDF, if you think about a nutrient analysis, you send in a feed sample or something like that, you may also get a report back on ADF, that's your acid detergent fiber, another component or indicator of fiber of that feedstuff. So let's talk a little bit about plant composition. Most plants are comprised of a greater concentration of neutral detergent fiber compared to their non fibrous carbohydrates. So the NDF portion is going to be a little less digestible and it's going to be digested more slowly in the digestive tract of cattle. Starch is going to be the main form of carbohydrate storage in plants, but this is going to be stored in the grain portion. So we don't necessarily think of that being in the plant, but the grain portion. So if we think about the chemical structure of how starch is stored versus how cellulose is going to be stored, you can see that figure on the bottom of the screen are a picture here on the left hand side is of starch. You can see our 14 linkages. These are glucose molecules right here. You can see how the structure is going to be different between those different glucose monomers. So we have alpha linkages versus beta linkages. So that affects the digestibility of those two products there. So moving a step further, we talked about carbohydrates are used for energy production. So as these products are broken down and digested and undergo fermentation inside the rumen, the end products of fermentation are going to be volatile fatty acids, also known as VFAs. We're also going to get other products such as methane, carbon dioxide, and ammonia. So you can see these short chain volatile fatty acids or VFAs over on the upper right hand corner. So these are the three main ones that we will see happen to occur or become present during digestion. It's going to be acetic acid, propionic acid, and butyric acid. And one thing to notice about these is their carbon length in their chemical structure. You see two carbons in acetic acid, you have three carbons here in propionic acid and you have four carbons in butyric acid. Those carbons affect the amount of energy that you actually get from each of those structures. As we add carbons, we add a little bit more energy to those products. So The proportion of those volatile fatty acids that are going to become present when feedstuff undergoes fermentation is going to depend largely on the type of feedstuff that's being digested. If we look at forage diets versus grain diets, we can see on a forage based diet, we're going to have much more acetate being produced relative to proponate and butyric acid. And On a grain based diet, you can see we're going to have an increase in that proprionic acid, so we're starting to increase the energy density, as well as the total concentration of volatile fatty acids that are being produced on a grain based diet relative to a forage based diet. That helps explain why we get a little bit more energy from those grain based diets relative to our forage based diets. So we typically see that our grain based diets have a greater digestibility compared with our forage based diets, and as we change or shift different diets that we're feeding to our cattle, the rumen microbial community is also going to adapt to those different feedstuffs because ultimately they have a different substrate that they prefer or that they're able to digest a little bit easier and use those byproducts that they're producing for their own growth. So each feedstuff can change the environment within the rumen and to which they prefer and can thrive in that can affect ultimately the production of these volatile fatty acid concentrations that we see on these different diets. So why am I talking about all this? This is going to be really important for the basis of why fiber is so important in cave diets. Before we get too far into this, I also want to touch on what happens what happens as those feeds are fermented is we produce these volatile fatty acids and just like they sound, they're an acid. Acids produce a low pH. so as the animals digesting its feed, we get this accumulation of volatile fatty acids and other acids like lactic acid, and what they do is they decrease the ruminal pH. If there's a large enough accumulation, it can cause something called ruminal acidosis There's different levels, if you will, different variations. We have subacute acidosis, which is a less moderate version of acidosis. But this is characterized typically at a pH that's below 5.5 to 5.8. Now, a more severe case of acidosis is what we call acute acidosis. This would be characterized by a pH that's going to be below a 5.0 or 5.2. Anytime that animals goes and consumes a meal of feed, the typical response is that we see a pH decline within a couple of hours of that meal. Then throughout the day, we typically see that that pH is going to then slowly climb back to normal before the animal is fed, say again the next day. So decreases in your volatile fatty acid absorption. And so if the animal has rumen acidosis or some of these digestive upsets that we're going to talk about, it can decrease volatile fatty acid absorption. We can also see damage to the rumen epithelium. That's the lining the tissue lining inside the rumen or the first compartment of the stomach. It can also disrupt barrier function. As nutrients and water are trying to pass. This can also allow for, say, microbes to potentially pass and enter into the bloodstream, which can cause some health issues as well. It is theorized that that may be why we have the problem with liver abscesses currently with some with feedlot cattle across the country. This is where fiber comes into play and why it's important. Instead of just talking about plane neutral detergent fiber, we're going to focus on physically effective fiber. What physically effective fiber is, it's the fiber portion, but it really depends on the physical characteristics of that fiber, such as particle length, buffering capacity, fermentation rate, and some other characteristics. So physically effective fiber, you can think of the physical characteristics actually play a role. Now, if we want to think about other types of fiber, let's think of some other feedstuffs, for instance, if anyone's familiar with distillers grains, it's very fine shows up like a meal. If we think about sifting that through one of these sieves here in this picture, most of it would show up in the really fine pan because its physical length and characteristics are very small. Now, for physically effective fiber, we're hoping to have some extra length particle length that's going to help form that rumen mat inside the mat inside the rumen. It helps with mixing. It helps hold particles together. It may help slow digestion a little bit so that we don't get this abrupt concentration of volatile fatty acids that can drive pH down as severely. Actually, in this picture is shown a Penn State particle separator, which is a means of actually checking a diet or say a TMR for the physically effective fiber within that diet. So this is something you can go out and do. It's got four different pans there or sieves that have different size holes in the bottom of them. So you can see that the top screen would collect your largest particles, and then we have a step below that and another step and then really fine particles. So depending on the contribution to each of these pans, there's a formula that we can enter that data into and that'll spit back a percentage of physically effective fiber for that diet. So if you're interested in that, we can certainly connect after this presentation sometime and go over that. So Before we get into some of the data, you may be sitting back here and wondering, okay, well, this is all great. How much fiber do I actually need in my diet? And I'm going to say it depends. Much like a lot of the science out there, it depends on your situation, as we talked about. There's a lot of different characteristics that play a role in the physically effectiveness of fiber. There's also some interactions of other feed ingredients that we haven't even touched on, such as grain processing. Each feed ingredient also has different physical characteristics that affect its digestibility. So all those characteristics, how they all interact with one another play a role on how feed is digested and how much physically effective fiber we actually need. So let's continue on. So I broke some of the data portion for this study down into two different sections. First, talking about younger animals or our calves, and then we'll focus on some of our larger animals or diets that are fed to our larger animals like a finishing diet. So first, I want to talk about calves. If we're thinking about developing diets for calves, the main goal is rumen development and then growth of that animal essentially. So again, in order to grow that animal, we need to be providing that animal with energy. And the best way, most efficient and effective way to do that is with the use of grains that contain a lot of carbohydrates in the form of starch to provide that animal with energy. Like I said, forages are less digestible. They don't have as great energy. So, That's why we feed a lot if we could feed as much energy as possible, we'd be able to maximize growth potential. But unfortunately, there are negative side effects, as I alluded to a couple of slides ago that affect digestive health. If we would feed primarily just solely grains, for instance, without any fiber as a means to um, slow down digestion or promote rumination to allow the animal to chew its cud and produce saliva to help buffer those acids that are produced in the rumen. We'd have a bunch of acidosis and bloat potentially, and those animals would be sick. They wouldn't be eating, and therefore, they're not eating and consuming enough energy, they're not going to be growing. So In an ideal world, if animals weren't going to get sick, we'd feed them as much grain as possible to give them as much energy and protein so that they could optimize their growth. Unfortunately, they'll get sick. So that's where fiber comes in. So fiber is, our fiber components, like I said, we typically see a lot of this in our forages. So if we're thinking of our hays, our silages, Those are going to be the ones that are able to provide a physically effective fiber based on their physical characteristics. So forage intake is going to vary for small calves, and this is possibly due to various factors such as the composition of their starter and then also what is being used as bedding. So if we're thinking about beef calves, they're primarily nursing a cow up until seven months of age. They may be consuming some pasture, may be consuming some hay, but we don't have great concerns about them over consuming grain unless potentially grain is being delivered as creep, which then we need to consider how we're formulating that creep so we're not getting overconsumption and digestive upsets in that regard. But otherwise, if we're talking about calves, we're thinking about maybe some calves that we're feeding from the dairy sector that are going to be raised up for beef. Typically, again, our goal is rumen development and growth of that calf. Typically, they're put on a concentrate type diet that's a pellet. It could be a textured whole corn pellet or some just do a pellet, there are meals out there. So depending on those various forms that that grain is delivered in can affect how much the animal is willing to eat and then ultimately because of how much it can eat, it's how much volatile fatty acids are being developed. And then, again, volatile fatty acids is energy. That's how it affects growth and performance in that calf. So from general findings in research with dairy calves, typically they see that voluntary forage intake in dairy calves is going to be around four to 5%, but it may drop to around 1% after weaning. So if we're thinking about this, during the first couple weeks, those dairy calves are not really consuming much starter yet. They're just learning what's in front of them. They may not be consuming much hay. But once they do start, we can see that they start with a little bit more hay, and then after weaning, that may drop down to 1%, and part of that is due to their intake overall. It's just that their dry matter intake of that feed is starting to increase much more rapidly as we've begun to replace milk from their diet. So here's a study from Hill and others where their conclusions of their study were to recommend 1.5% NDF from roughage in the diet of calves. They did four different studies actually in this paper here. Trial one, they fed straw. So if we think of straw, it's got a high NDF value around 80%, and they fed either zero, three, six or 9% chopped straw in the diet for those calves. So that contributes anywhere 0-4 to almost 6% NDF. In trial two, they fed alfalfa. Alfalfa is a little bit higher quality forage, NDF percentage of alfalfa in their study was around 33%. So they fed that at five, ten, and 15% in a chopped form to calves on their study. So that contributes around zero, almost 1%, just under 2%, and then just shy of 3% NDF coming from that forage in that diet. And then their third trial was looking at grass hay. So grass hay, we can think of as probably intermediate between straw and alfalfa as a feed source in terms of NDF. And the NDF value was around 55%. In that case, they fed zero, three, six and 9% chopped hay. Um, so NDF for those calves was 01.2, 2.4 and 3.6 for NDF from forage. So you can actually see all those different points from those three trials actually in these figures here. They have the percentage of NDF that's coming from those different forages, and then they have average daily gain over here on the Y axis on the left hand side. So in the paper, it's going to be reported in kilograms. I've actually put pounds in the red text over on the far left side. So and then 1.5% for their recommendation actually falls right in these highlighted green bars on each of these figures here. The first figure is going to show you the relationship between average daily gain and neutral detergent fiber from those forages and you can see that it declined. The more fiber that they were adding into those calf diets, we saw that average daily gain was going to decline. Now, in terms of the relationship of dry matter intake as a percentage of calf body weight, and then NDF from forage over here on the X axis, you can see it was a little bit more quadratic in its response and actually peaked right around that 1.5%. So they're able to maximize intake in those calves somewhere looks like around that 1.5 to maybe even 2% here for those calf diets, if we're thinking about NDF from roughage. Again, we're trying to get those calves eating enough dry feed where they're stimulating rumen development at an early age so that again, they keep eating more and more and we can advance their growth. Here's another study by Khan and others. They had a study where they had either no forage, so it's going to be abbreviated ST versus ad libitum chopped orchard grass hay. Ad libitum means free choice. They put as much chopped orchard grass hay inside or offer that to their calves as they wanted. Found that calves that didn't receive forage tended to consume more starter from the weeks of six to ten, but the forage fed calves, they had a greater total dry matter intake during this time. So if you think about the consumption of hay and starter, they consumed more. So we can actually see total consumption here in this bottom figure. The calves not offered forage are in the open symbols here are the white diamonds, and then the black squares would be your forage fed calves. And then in Figure B here, we can see how much forage orchard grass hay those calves were consuming. Obviously, you don't see the non forage ones because they didn't get any hay offered to them. And then the top figure here is starter. So you can see pretty similar where the calves not offered forage had a slight advantage in starter because that was the only feed offered to them after weleaning. So another finding of this study is that those calves that were offered forage actually had a greater reticulorumen weight. So they actually ended up slaughtering all these calves and studying how they were growing and how they were developing. And the reticulorumen weight would be the rumen and the reticulum together. So indication of how well that tissue is growing. Usually on forage fed animals, we typically see a larger digestive tract size because those tissues have to stretch just to accommodate the bulkiness of those feeds being offered and consumed. And additionally, they saw a greater digestive weight. One of the things I mentioned before, when we're feeding forages or fiber, we typically see that it can slow down digesta. We build up a rumen mat, if you will, of that digesta. So not surprising there. And then another great finding is that they also had a greater rumen pH. So with that inclusion of hay in their diet, we're actually able to buffer that rumen pH, so it's not quite as acidic. You can see here those calves that were not offered forage had a pH around 5.06 versus 5.49. One thing you may notice here too is that from our previous slide when we were talking about acidosis, if those calves are under 5.5, that's would be subacute acidosis. If we get down around 5.0 or 5.2, that's our acute acidosis. You can see probably differences in severity, but they both are experiencing acidosis on average. So this is mean or average pH. So over the course of the day, again, like I said, pH will drop and then it will increase. I have some figures on the next slide that illustrate that pattern, if you will. But overall, you can see that pH was quite low, but we did see an improvement or a buffering for digestive health with those calves offered forage. So like I said, this next study was done by Kim and others where they were feeding some calves for Let's see how long was it? Was it I think 11 weeks study. So in their diets, they had two different diets here illustrated by the control group and the red bars, and then in the blue bars would be their hay fed calves. For the experience, calves are subjected to three weeks of an adaptation period. This would have been four to six weeks of age. Then they had a pre weaning phase, which would have been seven weeks of age. Then they had a weaning transition, excuse me, at eight weeks of age. Then post weaning phase would be considered nine to 11 weeks of age. During that adaptation period of four to six weeks, calves were fed 300 grams or 1.8 liters of milk replacer, 600 grams of calf starter and then 200 grams of forage. As those calves got older at six weeks of age, those calves ended up getting divided into those two different treatments where the hay group was offered hay and then the control group was not offered hay. So at seven weeks of age, weaning was started for both groups by reducing that milk replacer. And then forage was restricted in the control group until the end of the study. So they had some prior and then all of a sudden it dropped off. I've adjusted this one figure over here on the left. This is rumen pH. Over here on the Y axis and then days of age or days after weaning, you can see here. So our weaning would have took place right here on this line. But interestingly, it looks like the control group already had a lower pH relative to the hay group. I don't know why they didn't adjust this data, but just for our visual sake here, I actually slid that line up, so that's what this other overlap looks like. Even if they were to start at the same time, you can see that those calves already started to separate as forage was taken away from the control group. So forage made a big difference in the pH for these calves. It looks like they started around 5.8. You can see the calves offered forage here continued to buffer the rumen pH. We were up around six and then even greater than around a mid six. Whereas those calves that were not offered forage usually stayed under a six. So could have been experiencing on average, some subacute acidosis. So we can look at this in a little bit more detail if we come over to the figures on the right. Would be time of day, so they have the various hours of the day, and then which week relative to weaning. One week out, the week of weaning, one week after and then three weeks after, we can see what is the rumen pH pattern in the rumen of each of these different treatments of calves. Again, blue would be your forage fed calves. You can see when those calves were initially fed indicated by the arrows. Anytime you have those calves are being fed, you have a big influx of energy Those feed products are going to be digested and you get an accumulation of volatile fatty acids that drive the pH down. So we see a sharp drop, and then they start to buffer that. Those VFAs get absorbed and rumen pH begins to improve. And if they're fed again, it drops and then it continues to improve. So typically, that's the pattern that we would expect to see. You can see that those calves that were not offered forage though, were not able to recover nearly as well as those calves that were able to consume forage. Interestingly enough, the pH for those calves in the non forage group, it looks like it got pretty stagnant for a while, where it just sat at a pretty low level there for a couple of weeks around weaning or shortly after weaning. Looks like maybe three weeks out they started to get some of that normal change to rumen pH again. But the main takeaway here is that without forage, those calves were not able to buffer rumen pH and were in a bit more of an acidic situation or experiencing acidosis. So in those cases, typically those calves are not performing as well, and it affects their overall performance. So in some cases, cattle are very resilient where they're still able to produce and perform. But eventually, sometimes those negative health consequences of acidosis and bloat can catch up to them. They may go off feed, and then we start to see, negative side effects to performance where forage fed cattle, even though they're maybe eating a little overall, their energy consumption is slightly less on average because we've diluted that by putting fiber in the diet, they're still able to perform at a high level because they're eating so well and their digestive health is a little bit better. So overall, there's a study that did a meta analysis, which is basically a review. They looked at a bunch of calf fed studies and what the effects of fiber were and study all those results to see what are the general takeaways. Because sometimes researchers don't always find the same results, so they want to see what is the general conclusion that we're seeing. I've highlighted some of those here today as we wrap up the calf side of things and we shift to our feedlot side of things, we're talking about finishing diets. But in terms of what they found, feeding forage increases their starter intake. So I think initially I talked about starter intake on the Khan study, and it was a little bit less. But again, think about the dilution. They have a bulkiness, a bulk fill coming from hay. So they're eating a feed product that has a lot of physical size to it that fills up space and can limit feed intake as well. So depending on the types of forages that are being studied, whether it's chopped or a long stem play a role in that. Starter intake increases and feed efficiency decreases more when alfalfa was fed compared with other forages. Which is interesting. We think about alfalfa as a higher quality forage. It has less NDF or less fiber component compared to some of our other fiber sources that are investigated like maybe grass hay or straw. I think in some of these studies, they looked at other things like silages and beet pulp, for instance. Starter intake and average daily gain are greater, but feed efficiency is going to be less when forage was free choice compared with if it was fed as a TMR. And then starter intake and average daily gain are going to increase more when calves are fed pelted or ground starters and foraged together versus a texture starter and forage together. So I think this is interesting. Remember I said earlier, how much forage is needed? Well, it depends. It depends on the types of starters that are being fed and the physical characteristics of the other feed ingredients. And in this case, if we're thinking about starter, that's the grain portion or the high energy portion that's going to produce the most volatile fatty acids and affect our pH. Those pelleted and ground products are much finer, so they're much more rapidly and easily digested relative to a texture starter that could take a little bit longer to break down and have a little bit slower digestion. So forage may actually help out those two that need a little bit of buffering. They need to slow down the digestion of that pellet and that ground starter. So that's why we may see improved starter intake and average daily gain when those are fed relative to the combination of forage and um textured starter or textured starter may just be able to perform a little bit better on its own relative to the other two. Then feeding forage increases ruminal pH. In their study saw this difference was about 0.3 and 0.45 units during the milk and post weaning period. Early on in that calf's life when it's consuming milk, about 0.3 pH units and then post weaning when milk's been removed and they're left with whatever those dry feeds that are available to them for those calves that were given forage were almost a half pH unit greater than those without forage. That's a big difference. But they also saw that by feeding forage, it did decrease VFA concentration, which we talked about right away, if you're feeding a forage based diet, you're going to have less volatile fatty acids being produced relative to a grain based diet. So a lot of those make sense. We're going to shift now to the next part and talk about what's Forge's role or physically effective fiber's role in feedlot diets. So if we look at general recommendations, Fox and Tedeschi in a paper from 2002, they recommended seven to 10% physically effective NDF on a dry matter basis to keep the rumen pH above a 5.7. So that's in the NASEM or nutrient requirement recommendations for beef cattle. They also make the point that there's many factors that can influence rumen pH. And with physically physical NDF only accounting for about 50% of the variation in beef cattle, Now, those who study dairy cattle, when they look at the impact of physically effective NDF, they say that it actually is responsible for about 70% of that variation. Quite a bit of variation is just dependent on the physically effective NDF alone. Like I said, there's a lot of other factors, feed management, those different feed ingredients, how the other feed ingredients are processed all play a role as well. So as I mentioned, one of the reasons that we feed fiber in the first place is to maintain digestive health. And one of the problems that we're seeing as a result of poor digestive health is the occurrence of liver abscesses. So like I said, it's typically thought or believed right now that acidosis can disrupt some of that gut barrier function that allows some of those microbes to pass the gut tissue lining and enter the bloodstream where they blood then takes all those nutrients to the liver so they can be processed. The bacteria go there and they can colonize and form what's known as an abscess. There's this really nice review by Reinhardt and Hubbert that was done in 2015. Here are a couple of points that they wrote about or talked about in their paper. So They found that 10% versus 30% ground alfalfa decreased liver abscesses and increased pH. Let me be clear on that, going to 30% decreased liver abscesses from 15 down to 2% and increased rumen pH from about 5.8 to a 6.0. That was a study done by Zin and others in 1996. Adding more forage, more fiber, improved rumen pH, We also saw less liver abscess, both those things check out and support that idea. Now on the terms of corn silage, we switched from hay to corn silage, Loerch and Fluharty, a study that they published in 1998, compared zero versus 15% corn salvage in a diet where they were feeding a whole or rolled high moisture corn in their finishing ration. When they measured liver abscesses, they saw a reduction in the corn salvage fed steers, only 15% for 15% corn salvage versus almost 30% in the 0% corn salvage. About 50% reduction, that's pretty good. They also found that decreasing 30-15% down to 0% corn salvage versus increasing 0-15 to 30% corn salage change the liver abscess prevalence in steers. As we typically think about feeding cattle, typically we start with a lot of forage, starting with 30% corn salvage in this case, and then we drop it down to 15% and then zero. So we're increasing the energy density, increasing the energy that we're offering to the animal to hopefully continue to advance growth and deposit fat, hopefully in the form of marbling for improved quality grade. So that's the idea behind that. However, they took an interesting approach where instead of going from high to low, they went from low to high. They started those calves right away on a 0% corn silage diet, so 100% concentrate diet, but then they added 50% corn silage and then 30% corn silage. And by adding fiber during the later portion of the feeding period, they actually saw fewer liver abscesses. So this would indicate that the late feeding period, those animals could benefit from having a little bit more fiber. Now, The caveat is that they're also giving up some performance for the most desirable performance from those animals during the end of the finishing period. So that's the trade off. You trade off, you get a little bit better digestive health, but you give up a little bit on feedlot performance and gain and efficiency of gain. Another study here by Reinhardt and others in 1998, they were feeding 68% corn silage or they were limit feeding a steam flaked corn diet with 25% corn silage to Holstein steers for 112 days. This resulted in seven and 8% liver abscesses versus 18% liver abscesses when they fed those steers free choice steam flake corn diet. So here, the researchers took the approach of monitoring feed intake and seeing how that impacted liver abscess development. So by controlling intake or having more corn silage in the diet, they're able to reduce those liver abscesses. But when they let those animals regulate their own intake and feed when they wanted to, they noticed that liver abscesses increased. Here's a few more points. Depending on, we talked a little bit about physical characteristics when we were talking about physically effective fiber. Here's a study from Calderon Cortes and Zinn in 1996 where they fed either chopped. This would be 2.5 centimeters, think about an inch or a long stem alfalfa, in a steam flake corn diet either at 8% 16% of their diet. Two different chopped lengths, but then also two different inclusion levels. And they saw that this resulted in a 12.5% liver abscess versus 0% liver abscess. So they found that 16 versus 8% hay inclusion improved ruminal pH, but the chop length did not. So chop length makes a difference on liver abscesses in this case, the finer chop that's going to be a little bit more digestible by that animal. It had greater liver abscesses. However, those one the long stem hay, that takes a little bit longer to digest, it slows down the accumulation of those volatile fatty acids. We didn't see any liver abscesses from those cattle. So that checks out from what we've been talking about so far. Now, another study by Loerch and others, interestingly, they were able to reduce liver abscesses in cattle that were fed 100% concentrate diet by adding six pot scrubbers to the rumen. We think about pot scrubbers that you may wash dishes with, they were able to get those into the rumen steers on their study and they found that they were able to act in a way to improve digestive health where they didn't see any liver abscesses relative to the cattle that did not have the pot scrubbers. Very interesting that those physical characteristics of the digestive, the feed ingredients that enter the rumen matter. It helps stimulate gut motility. Helps build that fiber mat, gives way to the concept of a scratch factor. There's some kind of stimulation in there that those animals need. Other factors like rumination time, salvation, and as we've been talking about the physical stimulation for proper rumen mixing and motility are definitely going to play a role from those different fibrous sources as well. So here I'm going to take a little opportunity to talk a little bit about liver abscesses and corn silage inclusion. There's a study done by Wilson and others from Nebraska where they did an analysis of a couple of different studies where they fed either 15 or 45% corn silage in the diet. This was a diet where the corn inclusion was 40 60. So 40% of that corn that was included was going to be dry rolled corn, 60% of high moisture corn. So it kind of changes up the um, rate of digestibility of the overall amount of corn in that diet, and then they had 20% modified distillers grain, 4% supplement. Then another factor that they looked at in those studies was diets with the use of Tylosin which is a macrolide that is approved for the approved to help prevent liver abscess development. Or they looked at feeding cattle without Tylosin. Then in the case of these two diets, 15% versus 45% corn silage, you can see the different NDF values there, 15.5% versus about 23.5% on the 45% corn silage diet. So in that table there, I have whether those cattle were, not offered Tylosin versus with Tylosin and then two different corn silage levels, and then the percent abscesses here. We look at those cattle that were not offered Tylosin. We can see that adding more corn silage decreased the amount of liver abscesses. Same with the amount of the inclusion of Tylosin. We can see there was still a reduction with those cattle that were offered 45% corn silage relative to 15% corn silage. If we want to look at this overall, we can see that even if we didn't include Tylosin 45% corn silage, reduced liver abscess is about the same with or without Tylosin. So it was able to do basically just as good a job as Tylosin was at reducing liver abscesses, if not maybe a little better because we're down to around 12% versus even 19, 20% with the inclusion of Tylosin. So it goes to show that the amount of fiber coming from corn silage played a big role. Now, we've done recently, we're wrapping up a study where we did a similar concept looking at different genetics, but we fed either Holsteins or beef cross beef Holstein crosbreds 20 versus 40% corn salvage. And in that diet, we also had high moisture corn, distillers grains, and then a supplement that carried your vitamins and minerals. So in our case, we had almost 22% NDF versus almost 29% NDF for our 20% corn silage or 40% corn silage diets. And Melanie, the grad student who's running this research project, actually calculated what the physically effective NDF of those two diets was for us using that Penn State particle separator. And you can see those percentages here. For our 20% corn silage, we had about 16.5% physically effective NDF, and then the 40% corn salvage diet, we are around 24% physically effective NDF. So if we look at the Holstein steers, fed either 20% corn silage or 40% corn silage, we can see that there was a fairly sizable reduction in liver abscesses. For those Holsteins fed 40% corn silage relative to 20%. If you come over and look at the beefs, the beef Holstein crossbreds, again, 40% corn silage made a huge reduction in the amount of liver abscesses relative to our 40% diet. So Again, big difference. We see that fiber can play a big role in how those cow perform. Interestingly, in this study, as we saw, we're able to improve or decrease the amount of liver abscesses, improve the digestive health, if you will, we actually didn't seem to give up too much in terms of feed cost of gain for these cattle that were fed 40% corn silage as well. That's a really positive finding of that study for those who are feeding cattle out there, particularly these corn silage based diets. So I'm going to wrap this up because we're nearing the end here. In summary, high grain diets are going to produce more volatile fatty acids and some of those components like lactate that are going to cause lesser ruminal pH or drive pH down and possibly lead to acidosis and compromise rumen health, as we talked about that can affect barrier function and that may lead to some of those liver abscesses. So forage inclusion in cattle diets is necessary to maintain proper rumen health. So like I was just saying, barrier function, nutrient transport, and then help with overall motility and mixing of those feed ingredients in that digest it inside the rumen as well. We know that forage inclusion can decrease feed efficiency, but it's a give and take. Are we we're giving up a little bit of a feed efficiency and overall performance, but we're also adding back some digestive health with that forage inclusion or fiber inclusion. Then the amount of forage or fiber inclusion that we want in our diet is going to obviously depend on other factors as well, and that's going to be the type of fiber we talked about different sources, whether it's coming from alfalfa or grass hay or straw or corn silage, your haylage, your beet pulp. I mean, there's a lot of different fiber sources out there, so type is going to play a big role. We talked about some of your byproduct fibers as well. We talked about distillers grains, corn gluten feed. They have fiber as well. But if we think about the size of those particles, they're two very different things. That brings me to the next point of fiber length and how effective is that fiber length that actually um stimulating digestive health. And then grain type. How is that grain processed? What are its characteristics and how fast is it fermented or digested inside the rumen is going to play a big role in the accumulation of those volatile fatty acids and its impact on rumen pH. And then the forage and grain inclusion rates that we have in diets. What are their ratios? Other factors that play a role. Days on feed are going to play a role for thinking about feeding beef cattle versus dairy cattle. Oftentimes, those dairy cattle grow a little bit slower or they're also on those high grain diets from such an early age that they've been exposed to a greater acid load over a longer period of time, and those I would say a greater number of days that you're experiencing acidosis or a greater acid though, could have an impact on the integrity of that digestive tract. So that may be one of the reasons why we see more liver abscesses in some of those cattle coming from the dairy herds, such as your Holstein steers. And then after that, we see maybe a slight improvement from our crossbreds and then down the way we see liver abscesses in your beef cattle too. And then ultimately, if we're going to include Tylosin in the diet too, we know that plays a role. So Those are a bunch of different factors that can affect the amount of fiber that we want to include in the types in our cattle diets, and each different stage of production is going to be a little different. How you feed those cattle is also going to play another role. So lots of things to think about as we're trying to figure out what type of forage to include and how much to include so we can get the optimum performance without hurting our cattle performance and efficiency of our operation too much. So much like is often said, cattle feeding is a science, but it is very much an art as well. So there's a lot of trial that goes on with it to figure out what is going to work best in your system because every operation is unique in its own way. Again, thank you very much for attending this session. We look forward to seeing you in the next session. So with that, you guys are welcome to go on about your day. Thank you.