[Music] now it's time for the second presentation the second presentation is going to to talk about factors of variation of animal digestibility from in vivo to in vitro this is going to be presented by Professor Eric by Newton who he is professor professor at eros University Department of animal science his focus area is in carbohydrates he developed a lot of implementation for analysis of and determination of carbohydrates I know him from a long time when we started to study barley do stability in our stations we follow his his determinations he was I think so I can say it's the person who put the world viscosity in the in the feed processing in the feed analysis so since him I his publications everybody knows what does it means viscosity in many others and Mangan also as well but an imp are we do a lot of studies in viscosity in our studies he was also he worked in culverts Research Center so I am going to ask if everything related to the brewing and we were and the pollution be beer it could be very important for animal nutrition people with more than 200 papers I think I set a lot of things for we have to to hear your presentations professor nonsense you have the floor [Music] thank you very much for this kind introduction dr. Prasad and ladies and gentlemen it's a great pleasure to come here today and talk about factors of variants of animal digestibility covering from in vivo to in vitro methods the points which I'm going to address here today they will just be a brief introduction then I'm going to talk about the digestive system of monogastric animals except defied by by pigs I am going to talk about the digestive processes in the small in the last intestines experiences of factors influencing the digestion closes in a small and large intestines then I'm going to talk a little bit about the static in vitro methods to assimilate the digestion process in the two parts of the gastrointestinal tract and then I'm ending up with a summary well as you mentioned I'm going to talk about in vivo and in vitro and one of the points which you can ask yourself of why nurse be interesting in vitro methods well we are interested in in vitro methods because that can be a way by which we can predict the nutritional value of a feat or ingredients but it's also important in the sense that it can be used as a to understand the mode of actions actions of processes in the different part of the gastrointestinal tract this can be the the mode of actions of additives as for instance enzymes and what can be used in vitro that is different models other static that yesterday models dynamic digested models kinetic models and digestion cell models so there's many different possibilities with my talk today I'm primarily going to to talk on on vevo animal models and also a static digestion models I'll come back to that later we're first looking on the digestive systems of pick and the digestion of carbohydrates in the gastrointestinal tract we know that we are secreting some of the alpha amylase is by the saliva and the major part that's secreted by the by the pancreas in addition we also have a number of other carbohydrates --is that is associated to the epithelia brush borders and which will break down the different nutrients along the lengths of the of the upper part of the gastrointestinal tract it will for most part converted into the into glucose but we will also take up fructose and galactose depending on the composition of the right digestion process that's what's going on here within the gastrointestinal tract this is what is provided to the animals in addition it's also so that we have a micro flora pressing and typically we are talking about the micro flora which are present in the in in the last intestine that's also where we have the major part of the micro flora but we shouldn't forget that along with the the lengths of the or in the stomach and also the small intestine we will also have microbial activity which actually also we start to break down some of the carbohydrates the micro flora they have in general far more diverse composition of the carbohydrates which are able to break down some of the more complex composed carbohydrate materials the end products that's predominantly short chain fatty acids and also lactic acids but an important aspect that is that in the smallest in the stomach in the small intestine we do not have any industrial fiber degrading enzymes was we had a Verity of microbial fiber creating enzymes present and the different parts of the gastrointestinal tract we're looking a little bit more detail into the digestion process if we have the stomach which actually is also a form of reservoir that that regulate the flow of digester into the small intestine and basically I mean mathematically you can model that by by these curves but what you also can see here that is that in the early phase there's a very very rapid outflow of digester from the stomach into the small intestine but at the same time it's also so that the digester that expression in in in the in the stomach they will be exposed to different pH is relatively high immediately after feeding a meal and then dropping as it get more empty if we're looking into the small intestine then it's the site for the degradation by industrial enzymes and basically so that when digester are coming out from the stomach they are propelled along the length of the small intestine and along with that processes they are exposed to a very high level of endo of industrial and funds which actually will break down the the nutrient relatively rapidly as you can see here from an in vitro digestion study away so that you will see that by the infant you're going to break down the neutral in this stage looking into how it's said it is with digestibility of different nutrients you'll see that for instance four stars there's hardly no digestion of the stars going on in small intestines in the first third of the small intestines there's a seasonal decoration but when it comes to the approximate in the middle of of the small intestine most of the nutrients or most of the stars that's us disappeared however depending on the type of stars you're you're you're feeding in some case you can feed feedstuffs with very content of resistance that's a very important part of the Stars will be digested in that different parts of the gastrointestinal tract as I mentioned before the stomach and the small intestine they also contain a lot of microbial enzymes and they are not going they are going to act on the Stars and other nutrients that's present there but they are also going to act on modifying the fiber components and this is data from from where we are looking at the end of the small intestine on the decoration of beta glucans and on arabinose islands and what you can see here that is that on average 65% of beta glucans industries they have disappeared already at the end of the small intestine with the arabinose islands little depending on the source it's only 13% this degradation they are not carried out by the industrial enzymes but they are carried out by the microbe reliance on such present there and why is beta glucans degraded to a much larger extent than the case of the arabinose Islands well be the glutens that's a relatively simple molecule that only requires few enzymes to be degraded and if you try to track for instance the molecular weight changes in the soluble eyes that beta glucans you'll see the degradation process already starts in the stomach's and then continues along the length of the small intestine with arabinose islands it has a more complex structure and they are by itself more resistant against the degradation and when we compare for instance the changes in molecular size we'll see arabinose islands they are far more resistant to digestion in your also see that it's only around 13% as compared to a 65% what you also can see here with the with a beta glucan that is that if you feed for instance and other ingredients that's also quite slowly digested as the case of lactose that that in itself will reduce the digestibility of beated okay so there's many active interactions here when it comes to the in vivo situation then moving into the - Turin process in the large intestine well it's the main seat for the degradation by microbial enzymes and basically when you're looking into it you'll see that the decoration that depends very much on the composition of the fibrous materials it is much more rapidly and more complete for fiber sources that come from non lignified sources as compared to those coming from from lignified sources and here just as an example when you feed a cereal soybean meal dives and you're tracking the degradation of of the different monomeric sugars along the length of the large intestine you'll see that four Irani gases and galactose which are markers for pectin containing materials the majority of the of the sugars they are broken down in the cecum and also the first part of the colon was with the silos and glucose within for this diet is markers for arabinose islands and also cellulose they have degraded more slowly and that is a picture which you see in general well i'm now going to share with you some data from representing a total of 21 different published their works and one unpublished works and also 78 diets this is the dietary composition you will see that there's quite a big variation in the different nutrients I should say the protein which actually is nitrogen multiplied by six point six point two five as the sea rose I only represent one diet the other they are they are high end but otherwise this is the ranks of composition of the different diets and when you then try to use ileal kind of late the pigs to to to look on Hamas are giving in and how much will you recover at the end of the small intestine and then say well we give this animal two kilogram of dry matter per day this is the values that came out of this calculation and what is quite sure here that is that the part that really influences the flow of organic matter from the small to the large intestine that is the intake of dietary fiber and it's also so that the dietary fiber which in this case here is a sum of non-starch polysaccharides in lignin they are primarily represented by non-starch polysaccharides but what we further can see that is there's also an influence on the flow of protein primarily because the fibers in itself will also represent some cell tissues which are not digested in the in the small intestine and therefore it's carried down to the last intestine in addition there's also as I shall show in a few minutes also an fx of the encapsulation of the potential available in cell structures with regard to fat you'll see that it's hardly no effect the same is actually the case with the with the flow of starts because when we are looking into it basically what really matters for the flow of starts at the end of the small intestine that is the type of stars you have ended ID residues that is probably some of an estimate of the influence on the industrial materials so if we are looking into it more specifically you can see you have a negative relationship between the the fiber in organic matter but you also have that in terms of the nitrogen and to some extent what you see here with a nitrogen that's partly because the fibers they the cell wall in itself contain some non digest of the protein but in addition is so that some of the cell structures can encapsulate some of the nutrients we shall then withhold from digestion in the small intestine and carried further down to the loss intestine in this case I have exemplified that with microscopic pictures of of the Allens and the sub islands layer of oats and you can see that when you have filled cell structures in the feet the same you actually have in the ileal digesta now moving on to the processes in the in the large intestine and I should say they here that there is an interaction between the flow of non-digestible residues and also the composition of the microphone and also the products that's formed in this presentation I'm only looking on using micro floor as you could catalytic provider of off decoration and science but basically what you are seeing here that is that the materials can either be fermented converted into short chain fatty acids in absorbed as such the major part will be absorbed and then you also have the the gases well there's other parts primarily those pressure in lignified tissues which will pass all the way down through the intestinal tract this is basically when we're looking into results from many studies what we can see what's happened there is particularly in the upper part of the of the last intestine a very active microbial fermentation leaving also many of the the relatively easily fermented materials degraded and then as you pass along the large intestine die some materials that is to a lesser extent degraded as i already have shown before and what we've typically see in the faeces here that is lignin cellulose in some all so on brands arabinose islands and i can just to give you an example here showing the decoration of of cellulose non starts polar sacrum and arabinose islands from different tissues of grains as in in in in rye and wheat and what you can see when you come to the outer part of the grain they are completely resistant and to talk about one single digestibility of our ravenous islands and and and and cellulose you have to realize that they depend very much on the tissue type and also the interaction with particularly lignin and again that's all or the total well the next part I'm going to talk about because I have to hurry up a little bit that is the prediction of the digestibility with in vitro methods I should say what I'm going to present here in the next part will primarily be based on on this model that was developed by boisen and Fernandez but I also acknowledge that there has been a number of newer developments within this within the in vitro masses as simulation systems and also other a computer-based control simulation digestion systems and again other types of methods that has been used but if you're looking into the the publication of abortion and firm and as you'll see that this is essentially a modeling of the total tract digestibility where pepsin is used to model the influence of pectin from the stomach the pancreas een for the influence of the N farms in the small intestine and this cosine as and as a model for for degrading the nutrients in in the large intestine and then you carried out a filtration steps at the end and if you're looking into how how these different steps they are they are on on the different on the digestibility of organic matter in vitro you will see that very much depending on whether it's poly or soybean meal pepsin will have an impact different between and then the pancreatin and then the viscose I'm will at from some further viscose I'm that's primarily an enzyme with a high activity of pectin pectin asia's and you can also see that in soybean meal where you have more pectin eases you also have a greater effect of these enzymes this model has been further developed also to account for the digestion Xin in the in the small intestine where they were doing a filtration step before and and not using the the viscous silence here and by using some of the differences in organic matter with the small intestine model as compared to the total tract model you can actually have an idea about the fermentable substrate however this the the the small intestinal model that are not completely representative for what's going on in the small intestine because in in in in connection with the digestion processes you will also solubilize some of the some of the soluble fiber components so in principle as if the small intestinal model has been used so far they all represent the digestion in the small intestine but you can you can modify that by performing a precipitation step with a seven with 80 percent of ethanol which will precipitate out the the the solubilized the fiber components and when you're looking into some of the differences here you you can see that by adding an ethanol precipitation step you can see that the you got some lower enzyme digestible organic matter values here and you also see that they are better represented in terms of a non star spaulos at rice because you are close to zero and in principle and with a system like this the non-starch polysaccharides in its component should be very close to zero because we not have any ends or any microbial enzymes involved but then you can also if you like to and and the idea behind that and also in the way we want to develop it further that was also to get a better clue on what was going on if we in combination with a digestion process in the small intestine was adding extra Dena's enzymes so that we better could study the effects of that and if you compare for instance the data here with what we have over here in terms of enzyme digestible organic matter and on the fibers component you see you get some represent a better representative of what's going on on the on the fiber fiber part and I can also mention that Yamauchi algae actually performed a study on a larger number of cereal grains in and in byproducts and what you can see here and also by looking on the equations that was generated that he got a very very nice correlation between the in vitro ileal digestibility and the total non-starter sack rights and also to when he took the total tract digestibility well so coming to the end the fibers that is the diet of components with with a largest impact on the digestion process in the small and the large since the intestine we found that in vitro but it's also when you adapt that to in vitro methods I will also say that in vitro methods can be used to understand the mode of actions feet additive interactions and feed animal interactions but we shouldn't forget that in vitro methods they represent simply simplify they are simplified representations of the in vivo situation to what extent we further and develop it in using dynamic digestion kinetic digestion cell wall cell model can you be used to fill expand our knowledge within this field or we also have to include the feet on the feet additive microbiota animal interactions that is an area that that remains to be seen in an area with a great interest and potential in in in the future so with this work thank you very much for your attention [Applause]