[Music] and good afternoon everyone so I want to thank the folks from Addis AO for putting this impose you together and invite me here today we have you know the the task I had been given really is one as being the first presenter I have to keep you awake after lunch because all your Bloods from your head now in your gut right so I suppose that's apropos for this topic this afternoon and really the other task I've been given really is to talk a little bit about to set the stage for what we're talking about with the seco system of the gut and what it really means and challenges that we're facing right so I know we're not in the US but if we look at the US market right now on where we are on any systems it's probably 50 plus percent of the market broiler today being reared and in any system and it's been amazing to see that story transcend over a period of about three plus years really from next to nothing a few challenges a long way but I really appreciate the companies that have put forward and they've done a really good job of dealing with those challenges so I always try and put my nutritionists hat on when I think about the gut and and those of you who have seen me talk number times I do kind of have that spin to it but with a little bit of a physiological twist because we really need to understand how that body is reacting to whatever it is faced with right so baseline at least and realize that the gut is not a static system at all but if we look in general across critters the gastrointestinal tract consumes roughly about one out of every five calories for maintenance which is amazing right turn air over of roughly 50 to 75 percent per day that changes and we'll talk a little bit about those changes and one out of every four proteins is actually secreted into the gut right so all of that is to maintain two real different functions real assimilate nutrients from whatever we're eating but protect the animal from what it might be challenged with right so very very different functions and if we think everything's happy it goes along so what I'd like to always try and emphasize that it is not a static system everything is changing throughout the day every day of the week depending upon how that animal is reacting and reacting to its environment changes happen in terms of peristalsis epithelial turnover rates which encompasses changes to the rates of proliferation program cell death in the case of pathogens actual necrotic cell death and differentiation of those cells towards different purposes we see changes to muse and production as well as composition changes to barrier functions changes to size of secretions being produced functions of those genes amino logical responses microbiota responses and the list goes on and on and we'll hear about a number of those types of changes in this echo system of what we call not only the bird itself but what's happening within the context of the gut itself so let's talk a little bit about parasol peristalsis really and as we look that at this and and Mike will talk about this a little bit more on the nutritional intervention side and and what we are trying to deal with but what I'm trying to to convey at least through this so it is just really the problem that we're dealing with right so subclinical challenges what we're looking at in terms of just apparent metabolizable energy this is with a 12 times normal dose Cox evac challenge seven days after challenge we see this dramatic drop from about 3,000 kcals per kilo all the way down a little bit below 2000 an amazing detriment over a very short period of time as far as dry matter retentions we're looking at roughly not quite a 10% reduction in parind dry matter retentions and with apparent nitrogen retentions going a little bit more beyond that so we're dealing with us right so this is the overt ability of the animal to assimilate nutrients and then cope with what's going on so all of these obviously is at the cost of growth and part of what we conjecture at least is can we mitigate some of these symptoms that these birds are going through to respond and deal with the challenge that's been put forward to it and our best hope is that it deals with it quickly sheds the pathogen and build some sort of longer-term response to be able to deal with it so that that period of time where that growth suppression loss of nutrient assimilation and energy assimilation is at its minimal just in terms of standardized ileal digestibility x' this is as a percent of diet just gives you an idea how many points of each amino acid loss that we're experiencing if you look a lysine with this type of challenge six days post challenge looking at about 17 points of lysine in the diet we're looking at four points of Metheny and threonine you're also looking at about 17 points which is quite considerable I realize this is probably towards the peak of that particular challenge as it's going through that process dealing with it we'll talk a little bit about how that animal deals with it and if it's able to deal with it just briefly as well let's first talk about some of those responses one of those responses I always like to to talk about Dogma right so if I asked audiences typically how long do you think it takes for a new cell and the gut to essentially replenish itself oftentimes we also always say 48 hours who thinks it's 48 hours nobody okay you've listened to me before thank you but this process is a very dynamic process right and then it's it's cells going through mitotic division along the the migration along this Creek Phyllis access they're going through a terminal differentiation which they ultimately go through a program cell death and ultimately slough themselves off into the lumen of the gut and this dynamic process of birth life and death is essential to that integrity of the intestinal epithelium now if you remember prior I talked about during that course of what is ailing that bird it can have different directions along that how many cells are going through proliferation how many how that differentiation process is happening as well as those undergoing program cell death so for graduate students I always encourage graduate students to go back into the literature we do call it re search but hopefully you all aren't recreating the wheel even with some of the new toys that we have today I want to make sure that we one of our friends at University of Arkansas Walter botching I love his his term and I'm gonna coin this forever is getting lost in a data tsunami and with some toys that we have today it's very easy to get lost in a data tsunami and recreate some science that we had known for a very long time okay if we look back into Monte and buried back in 1966 they were looking at this advent of trying to figure out where we were sub-therapeutic antibiotics at that period of time were coming on the scene and they were trying to figure out the functionality of what they did in terms of improvements in feed conversion so they inject at radiated thymidine into the perineum of birds kill birds over time to essentially see where those labeled cells had migrated along that crypt villus axis fairly simple process we do that today with varying unknown radioactive types of intermediates well it was interesting you know you look at birds collected along 3 8 18 24 and 48 hours you can see how far those had progressed along the the [ __ ] Phyllis axis and lo and behold you look at the jejunum roughly about 48 hours it traversed about 88% of the length of that crit villas axis now that's where a lot of us have taken that dogma we only read the abstract and a lot of that then perpetuated literature not only in the chicken world but also the human world and the Pig world and the mouse world all because of that single chicken from that particular point in time and that was only the jejunum that was only one part of the small intestine which is amazing because it only had gone halfway if you look at the duodenum or the ileum right so if you go and then calculate epithelial turnover of that system in the jejunum normal system it took about two and a half days about five days each in the duodenum and jejunum or essentially a replacement of about 20% in the upper and lower small intestine and in the jejunum roughly about 40% turnover per day now others went on Mary coats I believe she was in England if I remember correctly did that in both a conventional environment and a germ-free environment to try and see how this alters and different types of environments it was interesting and conventionally reared environment that turn over here and the ileum took those birds at roughly 3.8 days turn over about 26% per day but in that germ-free environment really that was a nine-day turnover and that's an amazing difference in magnitude of response if you think of that from a maintenance perspective to that intestine so where do the y's you know we always have been taking snapshots in time in terms of histology histology is very difficult to capture a very dynamic system I'm gonna do a Carl parson so let me repeat that please in terms of histology it gives us a snapshot in time and does not capture a ever-changing dynamic system so we always have to put those in context with what else is going on there are some things we can gather from histology but not everything right give you in terms of a coccidia challenge 1973 paper we've known this for a little bit of time amiri a survey line a challenge 250000 spoil a that Oh assist three and four days post challenge light blue bars here unchallenged birds and you see the challenge birds having a three hundred percent difference in turnover about thirty percent turnover per day in the duodenum but that persisted then into the jejunum and the ileum very dynamic process it is very very responsive you can see by the graph over here one of the things that's happening when I talked about that life and the birth life and death of that villus you can see that that tissue is responding obviously it does not have the tip of the villa's as you would think of it but yet that proliferative pool is very very different in that challenge bird so it is trying to replenish those inteiro sites very very quickly and that turnover is happening very very quickly so the time at which those cells are alive is very short but it is responding by increasing that proliferative pool and over time as that challenge dissipates it will live a little bit longer and you gain back that length of the villas Bob Teeter at Oklahoma did these studies in chambers a few years ago just to give you a snapshot of what this is in terms of the spectrum of coccygeal challenges we see it from zero subclinical lesions to over clinical agent lesions at varying ages from twenty to forty eight days of age but as that bird grows and that delay of challenge to that bird happens because the bird is bigger it's having to have more maintenance cost to that overall tissue something good to keep in mind as we we see things differentially within when things are happening out in the field consequences of those differences in in turnover rates and this is not a bird example but rather a pig example gives you an idea of where the dice acrid ace expression is happening and along that crypt villus axis right so more glucoamylase being expressed further down in that [ __ ] phyllis that villus axis within a little bit more Maltese coming along as you move up starting to express more sucrase and then lactase as you move very much more towards the the tip of the villa's this dynamic is important because it does take time for those cells to differentially expressed some of their functionalities Ahava I don't know should hoppers in the room there you are I love this this study so I always pull it I know it's a little old now it's dated it's over 20 year olds but it's classic right and you could explain it better than I could yeah they create a different pools of cells essentially from going from the crypt region on the right all the way to the villas tip just to look at on the upper side you're looking at Maltese activity and on the bottom you're looking at sucrase activity in the chick you know relatively mature Jake's 3 to 5 weeks of age it was very very interesting as you look at this you understand that that Maltese activity is also expressed much more along that the upper portion of that villus similarly sucrase activity more up along that upper side of the village so 34 to 40 percent more in that upper 40 percent of that crypt villus axis now I mentioned this partly because that that absorptive you know digestive and absorptive capability if those cells aren't around long enough they aren't able to express those functions so it's interesting to see folks looking at different things now that we can measure things via gene expression and I can tell you if you're looking at the whole tissue and you just have not as much villus there I can tell you that some of the things you're going to measure from a nutrient transporter I could predict fairly easily what those are going to be just because you have a very different mucosa to submucosa relationship so we need to think through some of these dynamics as we're doing some of these studies to make sure that we're understanding all of those in a fast-forward to look a little bit at mutant production there are some things some interesting things that happen to this protective layer of the gut as we we move into a challenge so to speak from a nutrient perspective we know the threonine is five to seven percent of that endogenous amino acid loss in the diet tayo who's now at University of Kentucky has shown that we know that 30 percent of that loss of mucin 30% of that threonine is mucin in the case of the pig it really is that that very first line of defense and part of the question is we know that it changes in dynamic at least from different cereal grains and and from different non-starch polysaccharides but we know we can intervene at least from different feed additive perspectives to try to to alter not only how much is produced but then also potential composition of that museum and that is probably key I think in one of those unexplored areas of because really that is home an interface to a lot of that microbial community so those folks looking for a new research area and the gut I think that's that's fodder for one of those earlier studies we had done in diets without carvacrol and with carvacrol supplementation we see that the carvacrol supplementation really increases total gaba cell numbers and really that's as a particular response to what is happening within the that tracked further studies that we had done looked at both corn the first three bars on the left and wheat based diets the the next three bars on the right with and without carvacrol or thymol and the second bar is carvacrol the third bar is with thymol and i think the most interesting thing that we saw with this was was twofold one we could alter expression of the predominant secretory mutant Mewtwo we also saw that it was transcriptionally regulated by essential oils the other thing we did we pulled out the mucin essentially purified it and then essentially dried it down to essentially see how much water was within it just to give us an idea of kemple chemical composition of that museum and as we would expect the wheat based diets yes they didn't hold as much water meaning they were more viscous versus those as you see in the corn based diets on the left a little bit but what it also told us on that cue that that post translational modification was that with some of these essential oils we can alter that chemical composition such that in the face of having no enzyme present we could change the hydration capacity of that muse which is really cool if you think of that as to how that dynamic is going to play out there and into interface with different microbiota in the gut it's relevant especially because we know that that perfringens is a mucolytic type of bug that that likes to take advantage of some of those things as well well we know that the the gut is chronically dealing with with these different insults and challenges question is always does the animal get access to that substrate or is it going to be the microbiota simply take a carbohydrate gross energy is for kcals program if it gets converted to a volatile fatty acid that only gives you 2.8 K Cal's per gram relatively speaking a 30% Lawson and gross energy huge difference kind of coming into the question of can we deal with part of these challenges and we'll hear a lot about immunological challenges to to how we're dealing with some of those in terms of the ecosystem of the gut from tiles previous study I showed you the left part of this earlier at least on the differences on energetic utilization due to this 12x challenge of Cox evac in terms of we're only considering the energy loss differential we were talking 3271 kcals in the unchallenged birds versus the 1785 in the challenged parts a differential of nearly 1500 kcals per kick now we know if we try and account for that you know that's probably over an 18 and a half percent fat diet and I don't know anybody that could feed commercially an 18 and a half percent fat diet it just is not practical right so we know right off the bat that these energetic drains are difficult to really deal with unless you're addressing the core of that animals response okay dealing with that pathogen hopefully not causing too much damage but dealing with it very quickly to get rid of that pathogen so we developed a second follow-up study really to see if we could deal with that at least from the terms of that amino acid uplift and in this particular study we did this with a full complement of lysine methionine threonine isoleucine tryptophan and isoleucine and baling to bring back what had been lost in terms of that differential and amino acid utilization body weight gained at least with this diet versus the comparative challenge group no difference in three-week body weights however we did become somewhat intermediate versus that of the unchallenged control meaning that we did were able to pick up that differential in feed conversion so can we account for this nutritionally there's been different means and strategies to do so well energetically probably not from an amino acid perspective possibly and partially but that is only part of the story right I'm running short of time here the last I'd like to touch on only just briefly is is partly also a cost based type of process that at least my brain tries to process from an innate immune perspective we know that this response really causes a reduction in feed intake for a period of time it causes catabolism to to produce a full complement of those amino acids which is different for those particular acute phase proteins as well as the complement of different immunological proteins that are being produced some total we know beyond that feed intake reduction some total it's about 10% of nutrient use but all of that is also variable depending upon the amount of pathogen and how variant that pathogen is that that animal is dealing with that complement of amino acids is very different the example I have here is just on immunoglobulins as you see in the inset on the right whole body threonine contents on the Left bar versus mucin in the middle and IgA on the right so very very different in terms of one of our third most limiting amino acids using composition as you just saw prior very very different versus whole body protein so if I could sum up at least take-home messages I want you to all realize that this is a very dynamic system and it really is truly a system it is adaptive to those responses to try and deal with the challenge as well as that ingredient matrix and it will alter those endogenous maintenance nutrient energy digestibility as well as secretions to deal with that particular challenge the level and how it deals with that challenge is really dependent upon the amount of pathogen the virulence of that pathogen and other things that would predispose that animal to a differential type of response whether that be coxy or other things within its environment now the time and really it is a time spectrum of that immunological type of response and then recovery from that response will really very nutrient need and for us that are used to weighing things on a bi-weekly basis or weekly basis realize that oftentimes as we're looking at some of these strategies we may miss some of those responses just because of how we've done other traditional types of studies and in these cases with this very dynamic system being able to pick up those differentials it may not be such if you're weighing Birds every two weeks or if you have variants in that population from individual to individual but it does and because of time change nutrient use efficiency and changes to that tissue maintenance needs so with that all I'd like to turn back to the moderators at this time so thank you [Applause]