This episode of the Real Science Exchange podcast was recorded during a webinar from Balchem’s Real Science Lecture Series.
This episode of the Real Science Exchange podcast was recorded during a webinar from Balchem’s Real Science Lecture Series.
Choline was discovered in 1862 in pig and ox bile (“chole” in Greek). It is a simple nutrient containing five carbons and a nitrogen. Choline is considered a quasi-vitamin since its requirements and de novo synthesis are both higher than the B vitamins it’s similar to. Pigs can synthesize more choline than chickens. Choline is considered to be a conditionally essential nutrient depending on the physiological stage and choline production ability of the species being considered. (3:29)
Choline is involved in cellular maintenance and growth at all life stages. In particular, it’s involved in neurotransmission as a component of both sphingomyelin and acetylcholine. Phosphatidylcholine is a major component of cellular and organelle membranes and is involved in lipoprotein synthesis for the transport of lipids. Choline is converted to betaine upon oxidation, and betaine plays an important role in one-carbon metabolism as a methyl group donor. (8:43)
Dietary-free choline is preferentially used for acetylcholine and phosphatidylcholine synthesis. Phosphatidylcholine is the most abundant form of choline in the body. In general, water-soluble forms of choline are absorbed faster and have a higher tissue incorporation rate than lipid-soluble forms. (14:58)
Clinical signs of choline deficiency include reduced growth and reproductive performance. In pigs and chickens, choline-deficient diets lead to lipid accumulation in the liver. In broiler chickens, perosis is a classic choline deficiency sign and may progress to slipped tendons. From human studies, we know that insufficient methylation capacity during early development increases the risk of neural tube defects and impaired cognitive function. (16:44)
As animals age, their dietary source of choline transitions from water-soluble forms to lipid-soluble forms. Mammalian young receive water-soluble choline from milk, and avian species from the egg yolk. After weaning in pigs and at the hatch in chickens, the dietary choline source transitions to lipid-soluble forms found in oilseed meals. Dr. Dilger goes on to describe choline concentrations in common feedstuffs and supplements. Feedstuff type and processing methods have a profound influence on bioavailable choline content. (19:16)
Dr. Dilger details some of his work with choline and betaine in poultry diets. The requirement for preformed choline is relatively high for poultry because they lack capacity in a particular methyl transferase enzyme responsible for de novo synthesis. They also have relatively high choline oxidase activity which favors the formation of betaine from choline. Betaine is critical as a buffer to counteract the toxic effects of uric acid in the avian kidney. Dr. Dilger describes choline dietary requirements for avian species. (27:38)
Pigs have more efficient methyl transferase activity for de novo synthesis of choline. Sufficient choline is provided by milk and practical diets. For growing pigs consuming corn-soybean meal diets where methionine can completely spare choline, there is little benefit of choline supplementation for growth. Choline requirements increase for gestating and lactating sows. Swine requirements for choline were set in the 1940s and 1950s. Dr. Dilger believes these requirements need a second look given the great changes in pig and crop genetics since the requirements were originally established. To that end, work in his lab has shown that choline intake during gestation and lactation influences sow milk composition, body choline concentrations and forms, metabolomic profiles and brain development of pigs. (35:18)
In conclusion, Dr. Dilger considers choline a pervasive nutrient due to its crucial metabolic roles. Species-specific idiosyncrasies drive choline requirements, and analytical data for choline-related compounds is lacking. Different forms of choline have different metabolic kinetics and the potential for choline deficiency remains a practical issue. (46:15)
In closing, Dr. Dilger answers an extensive set of questions from the audience. Watch the full webinar at balchem.com/realscience. (48:32)
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Balchem VO (00:00:00):
The following podcast is taken from a webinar presented by Dr. Ryan Ger from the University of Illinois, titled, understanding Choline and Overlooked Nutrients in Pigs and Chickens. To view the full webinar and access the slides referenced during this podcast, visit bal chem.com/real science and use the search bar to jump to this webinar from February 23rd, 2021.
Balchem VO (00:00:32):
New research is changing everything we thought we knew about Choline's impact on the cow and her calf and top scientists have a lot to say about it. They're presenting new research that supports choline as a required nutrient to optimize milk production choline as a required nutrient to support a healthy transition choline as a required nutrient to improve calf health and growth, and choline as a required nutrient to increase colostrum quantity. This new research is solidifying Choline's role as a required nutrient for essentially every cow, regardless of health status, milk production level, or body condition score. Learn more about the science that is changing the game and the choline source that is making it happen. ReaShure Precision Release Choline from Balchem. Visit balchem.com/scientistssay to learn more.
Scott Sorrell (00:01:35):
I would now like to introduce Dr. Ryan Dilger. Dr. Dilger is an associate professor at the University of Illinois, where he studies the interaction of nutrition, immunology, and neuroscience. He received his BS and MS degrees at Purdue University and completed his PhD and postdoctoral training at the University of Illinois working with pig and chicken models. Ryan's research solves practical nutrition issues faced by modern animal agriculture. He focuses on comparative animal nutrition with an emphasis on biochemical aspects of proteins and amino acids, but also strives to integrate immunological and behavioral outcomes as related to overall animal health. His research projects can be broadly categorized into two areas, practical nutrition and health issues facing production, animal agriculture, and fundamental nutrition and developmental questions studied using the pig as a transitional model to improve human health and wellbeing. Dr. Dilger welcome.
Dr. Ryan Dilger (00:02:40):
Very well. Thank you, Scott. And I'd like to, to thank all the organizers at Balchem for, for, I've given me an opportunity today to talk about a nutrient that's very near and dear to my heart, in choline. So Scott mentioned I'm an associate professor at the University of Illinois Department of Animal Sciences. My, my background's in swine and poultry nutrition. And today I'll mainly be talking about one part of our lab, which we refer to as Noah, our nutrition for optimizing animal health. But I also have affiliations more on the human nutrition side through the division of nutritional sciences and also through the neuroscience program, where we've also looked at choline from the respect of a brain development as well. But Dale will be talking specifically about pigs and chickens and why I believe we can give more emphasis to choline which I'm considering as an, an overlooked nutrient in monogastric nutrition.
Dr. Ryan Dilger (00:03:29):
So before we get started I'd like to just thank everyone for attending today. We're gonna give a little bit of a background and, and give a primer on this nutrient that we call choline which has been known for some time. This was discovered in the mid 18 hundreds as isolated from bio also known as coal from the Greek derivation there. So we're talking about a very simple nutrient in choline, has only five carbons, and it contains a nitrogen as well. And what I'd like to do is to walk through some of the functions and metabolism of choline, why this is then relating to the amount of choline that's needed in the diet of a pig or a chicken, and talk about what happens if we don't get enough choline into those species. From there we'll talk a little bit about the bioavailability and, and the content and concentrations that we might find in, in feed stuffs, and how we can then be able to understand how to set the dietary requirements for those species.
Dr. Ryan Dilger (00:04:18):
And so this really does come down to some of the different idiosyncrasies or the ways that metabolism is working in pigs versus chickens with regards to how important choline is going to be and how much we need to add into the diet. So we'll start by, by just a little bit of background in, in defining choline also known as trimethylamine. So a fairly simple compound here shown in its chemical structure. So containing three methyl groups, and these are going to be important as we think about one of the, the third function in its conversion into bane and donation of those methyl groups. But a nitrogen, two carbons and a hydroxyl. This is a very simple chemical formula, and for this way, we often combine or think about choline as related to the B vitamins, but in fact, it's not truly meeting the definition of a vitamin.
Dr. Ryan Dilger (00:05:05):
And so often referred to as a quasi vitamin. The reason we we refer to it as that is because unlike the B vitamins, choline is, is found at fairly, fairly high concentrations, and the requirements are much higher than the B vitamins. We also have adequate de novo synthesis in multiple species, and we'll talk about pigs versus chickens here today. With pigs being able to synthesize more than chickens can and in some regards then choline can be considered as a conditionally essential nutrient conditionally here, meaning depending on the stage of life, the ability of the species that we're talking about for their ability to produce it, there is some possible choline, production endogenously but if the animal can't produce enough of it, then it becomes essential to get that in the diet. When it comes to humans, this particular nutrient was defined as essential in 1998.
Dr. Ryan Dilger (00:05:56):
So it's only recently, relatively recently that we've recognized the importance of choline. And frankly, only about 30% of humans are getting enough choline in their diets at any given time. This becomes even more important in women who are of childbearing ages. And so that same is going to apply when we think about our agricultural species as well. And we'll talk about pigs and chickens here today. We'll talk through a number of different metabolites that are involved with choline and how these have different functions and are related to the requirements of choline that need to be in the diet. But again, keeping in mind that choline, not a traditional vitamin, can be synthesized endogenously, though it's a fairly lengthy metabolic process for that to occur. So we're gonna focus on the various forms of choline that we might find in the diet, and that will relate to bioavailability, that will relate to the amount that's needed in the diet as well, in terms of requirements.
Dr. Ryan Dilger (00:06:50):
But first let's start talking about what are the different forms? 'cause I'll be referring to these throughout the presentation. I've separated these here on the top into those forms that are water soluble with free choline shown here on the left. So again, simple chemical structure. And what's highlighted in the blue box would be that actual choline component per se, as we incorporate it into other compounds, including phosphocholine and glycerophosphocholine. So here we're, we're simply adding a phosphate group on or attaching that with a glycerol. But in all these forms, these are being polar. These are all water soluble forms. So these reach the liver via portal circulation and are able to circulate throughout the body in that water medium as opposed to the lipid soluble forms. So here, in addition to that phosphate group, we've now added the glycerol with additional fatty acids, so R one, R two, referring to specific fatty acids that are added onto this.
Dr. Ryan Dilger (00:07:43):
So making it much more nonpolar in its chemical nature. So phosphatidylcholine having two fatty acids attached here with on the third carbon of that glycerol, the, the ester linkage here, two a choline per se, so phosphatidylcholine or also known as lettin, does contain choline per se add as does syngo myelin. So the condensation here with the ceramide molecule, both then phosphatidylcholine and sphingomyelin being in the lipid-soluble form, these are going to be transported and metabolized differently because they are not polar as the water soluble are. So these are typically in a mammalian species going to be packaged into chylomicrons transported via the lymphatic system. And so of course that will be a little bit different in poultry, which are going to handle lipids differently. But just highlighting here again, that phosphatidylcholine and sphingomyelin are two forms that are lipid soluble as opposed to free choline, phosphocholine, and glycerophosphocholine.
Dr. Ryan Dilger (00:08:43):
So in general, we can kind of couch the functions of choline into three or four main areas. And, and in general, they're all relating to overall cellular maintenance and growth across the life stages. So by that I mean that these are important at all different ages of animals. One of the main primary functions here would be that in its role in neurotransmission, and we can think again as sphingomyelin as a primary component choline, there is serving then as part of the myelin, which is going to wrap around an axon. So we have in the, the axonal length, we have the ability to transmit an action potential that is potentiated by the ability to wrap that in myelin, have that sheath available to conduct that information from one end of the axon to the other. The other role in neuro transmission is in the formation of acetylcholine.
Dr. Ryan Dilger (00:09:30):
So as a primary neurotransmitter in this regard, it's going to be packaged into vesicles that can be released at the synaptic cleft and either one axon communicating to another axon or at the neuromuscular junction. But in, basically we're talking about cholinergic neurons. And so part of the parasympathetic, parasympathetic nervous system the ability to communicate information also related here would then be the component of phospholipids. So as part of here, we're thinking about membrane synthesis, so both the lipid bilayer membrane that surrounds an individual cell. And we can think of these individual fatty acids, but phosphatidylcholine, especially being integrated into this, provides some polarity in a nonpolar environment of that lipid bilayer. This would also apply to individual membranes of organelles within the cell. That also relates then to lipid transport. So phosphatidylcholine especially being part of lipoprotein synthesis.
Dr. Ryan Dilger (00:10:29):
And we can also relate this back even to carnitine synthesis for the overall transport of fat, not only within the liver and processing, but throughout the body as well. So really neurotransmission membrane synthesis and lipoprotein synthesis. These three are going to be the top priorities metabolically for the use of choline in the body. That's not to downplay. However, this fourth mechanism or fourth role for choline being converted into, to beane being oxidized there. And then its role in one carbon metabolism. And that's perhaps the more well known functions of, of choline from an animal health perspective, animal nutrition perspective. And we'll focus on that role here as well. So again, the ability for choline to ultimately donate a methyl group via beane to methylate any number of, of proteins throughout the body in a number of different roles.
Dr. Ryan Dilger (00:11:20):
So just to orient us and as a good nutritionist, I'll do a little bit of background with the, the overall metabolism, but again, keeping an eye on where choline serves as a critical function for, for neurons, for lipid metabolism, and then for methyl donation, which I'm catching here as epigenetics, but the ability to donate a methyl group in other metabolic functions. So we start with choline on the primary roles here. Again, conversion to the seal choline, very simple. We can also go in the second direction for this to be converted to phosphocholine. And ultimately through the cytidine diphosphate choline pathway or CDP co choline pathway, we're getting the conversion of choline ultimately to phosphatidylcholine. Again, that can be done endogenously. And that phosphatidylcholine or denoted here is PC, can then serve as the metabolic precursor, toing, myelin, and glycerophosphocholine as well. So again, these functions, what I'm showing here, are the primary metabolic functions of choline.
Dr. Ryan Dilger (00:12:14):
They're going to be used and have higher priority than others. But what we know mostly, and where we've heard about this is the conversion of choline. And it's in a relationship with butane. So this is occurring by a, a double oxidation step. This is an irreversible conversion. Beane actually does not contain choline, but it has been oxidized from choline. And that'll be important as we think about the, the relationship there. But bean is then serving as dimethyl, gly as trimethylglycine, the ability to donate one of those methyl groups to homocysteine, to rem methylate that to methionine. So in the conversion in the remethylation of homocysteine to methionine beane is providing about 50% of the remethylation capacity. The other 50% is coming then from the, the vitamin B12 and the folate related pathway. So here we're talking about a, a specific enzyme, bane homocysteine, methyl transferase, or BHMT.
Dr. Ryan Dilger (00:13:11):
And again, this is referring to about 50% of the ability to produce methionine endogenously, which is going to be an important amino acid, and either first or second limiting for our pigs and chickens. So, owing to the fact that we have both bane and folate serving as methyl donators here, we know when we have redundancy in a metabolic pathway, how critically important that's going to be. So methylation is certainly an important role here. And ultimately, we get into the methionine cycle where this can be converted from methionine to densil methionine. Then that methyl group that may have come from VA can be donated to hundreds of different methylation reactions within the body forming il homocysteine and back to homocysteine again. So again, this is a conversion point where we are talking about the methionine cycle, and just one of these methyl transferases is what's important here today.
Dr. Ryan Dilger (00:14:02):
We can actually take phosphatidyl ethanolamine or pe and through a three methylation reaction, bring this ultimately back to phosphatidylcholine. So completing another cycle here. So this is a particular enzyme that we will come back to, especially with when it comes to chickens, highlighting that chickens have very low ability to convert phosphatidyl ethanolamine into phosphatidylcholine. One other pathway to bring here would be that of microbial fermentation. So any dietary choline, any of that which is present within the ga, the gastrointestinal tract can be converted through microbial fermentation to a trimethylamine. That trimethylamine can be absorbed by the, the host and oxidized to TMAO which is, is then going to be excreted via the urine. But this is just another path that if you're looking into the roles and the, the functions of choline, this can be actually acted upon by the bacteria and have an effect on the host as well.
Dr. Ryan Dilger (00:14:58):
So with that metabolic backdrop in place I just wanna highlight again that dietary free choline is preferentially going to be used for the synthesis of acetylcholine and for phosphatidylcholine, these are, if there's any choline available, they're going to go towards these functions first and phosphatidylcholine or PC is the most abundant form that we'll find in the body, and I'll provide some of that evidence from the, a swine study later. So it's estimated that up to 70% of the hepatic phosphatidylcholine is actually synthesized via the CDP choline pathway. So again, conversion from free choline into phosphatidylcholine with much less efficient synthesis coming here via the PEMT or phosphatidyl ethanol, mean methyl transferase. So that enzyme is going to be less efficient than the CDP choline pathway, which is why most of it's coming endogenously here via this pathway. There have been studies that have been done to show that all forms of choline that are via the diet can be absorbed, but they certainly differ in their metabolic kinetics.
Dr. Ryan Dilger (00:16:01):
And by that I mean, how fast are they going to be metabolized and available for conversion into other forms. So in general, in the water soluble forms, the free choline phosphocholine and glycerol phosphocholine are absorbed faster, so higher in the GI tract, and they actually elicit a higher concentration or incorporation rate of choline containing compounds within the body. This is as compared to lipid soluble forms. And again, that will be important as we talk about what form are our pigs and chickens receiving in the diet of choline? And mainly it's going to be here in the lipid soluble form. So again, this has implications towards pharmacokinetics and the ability to, to deliver this particular nutrient in a way that's efficient for our animals.
Dr. Ryan Dilger (00:16:44):
So what happens if we don't get enough choline? If we have choline deficiency we can get clear reductions in, in growth performance, and this is going to occur in both pigs and chickens. And most likely, this is related to the accumulation of lipids within the liver. So shown on the top here, we have livers from control, animals from healthy animals receiving adequate choline, and on the right we have those animals which have received a choline deficient diet for some amount of time. So choline deficiency can manifest quite quickly, especially in chickens. It's in chickens that we would have defined choline deficiency. And you can see this lipid accumulation shows as a, a discoloration, a lightning. So this is the actual buildup of fat within that liver that's then leading to the reduced growth. Reproductive performance also related here because of the importance of choline for neuro development early on, some of those processes but also from an epigenetics standpoint, I won't touch too much on that today.
Dr. Ryan Dilger (00:17:43):
But just know that there's been some, some evidence towards that towards choline its relation to betaine and ultimately providing the ability to methylate DNA, so perhaps more over overtly from a clinical sign perspective, we know tissue development abnormalities are going to occur with choline deficiency and mainly being with bone and cartilage formation. So this deficiency was first defined or as best defined in the chicken. This is a classic choline sign known as osis or chondra dystrophy. So here we're, we are relating to the, the inability to properly form that, that cartilage within the joint. What we're seeing then are some leg problems, especially in, in broiler chickens where we're having this slipped tendon. Once this gets to a, a more severe state. So between lipid accumulation of the liver and posis and the broil of chicken, these would be the most overt signs that we, we can point to.
Dr. Ryan Dilger (00:18:38):
But certainly we know from human studies as well that an inability to have enough methylation capacity, especially during early development stages, also increases the risk for neural two closure defects, and also can have some untoward effects for cognitive function as well. So we don't think about these in an agricultural realm, but just understand that the main thrust when thinking about choline and getting enough choline in humans is really about, again, those reproductive years and early developmental steps that are, that are requiring high concentrations of choline for the ability for, for methylation and other functions.
Dr. Ryan Dilger (00:19:16):
So we'll switch gears a little bit and talk about where do we find choline. So what are the dietary sources? And it really does depend on the species we're talking about. And what is the physiological stage for what type of form are they being are they ingesting? So in general, I'd say the animals are transitioning really from water soluble forms to lipid-soluble forms. And by that I mean either mammals receiving lip water soluble forms in milk or avian species through the egg yolk. Both cases we're talking about free choline, phosphocholine, and glycerophosphocholine. All of those species and including humans, are going to transition onto foods that have more of it in the lip liquid soluble form. And that in our agricultural species, especially referring to oil seed meals I say that with h for pigs, certainly if we were going to be weaning them, it would be about three weeks of age that they would first be receiving soybeans in their diet.
Dr. Ryan Dilger (00:20:08):
But with chickens, we're starting them on soy-based diets basically at hatch. So that's going to be important because those oilseed meals contain mainly choline in the form of the soluble phosphatidylcholine, also known as lety. So main sources are going to be of animal origin. But for our pigs and chickens, mainly they're seeing this through corn, soy type diets especially with oil seeds having the higher concentration, and we'll talk about the different bioavailability as well, and that bioavailability does differ. So how much are they able to extract from the diet certainly differs based on the, the type of choline that's being present there, and also the form of that choline that's there. So both the ingredient type and the form of choline that's present are going to be important. Back in 2004, the USDA, the United States Department of Agriculture did start the most complete data set of foods that contain choline related nutrients.
Dr. Ryan Dilger (00:21:03):
Of course, this is related to human nutrition. So those sources of, of choline don't always abide to what we're talking about in animal agriculture. But we have started a, a project part of the National Animal Nutrition Program and feed composition database. You can go to animal nutrition.org. We are starting to collect information in choline and trainer to nutrients that are available within that dataset. So the National Animal Nutrition Program, or NANP, makes this as a freely available resource which we're trying to compile information on the analyzed concentration in the form of different choline containing compounds within common ingredients that are used in animal nutrition.
Dr. Ryan Dilger (00:21:43):
As related to that we have had some recent work looking at choline containing feed stuffs, again, pertinent to animal agriculture. And we've gone through and looked at any number of samples of corn, of corn DDGS, dried distillers grains with solubles, wheat and soybean. And we can look here at the total concentration on the Y axis here, the units being milligrams per kilograms or in parts per million. And we can see corn having around 500, about a quarter of that, which is found in DDGS or soybean meal. So clearly in the ethanol production process, we are not extracting choline in this way. So we are actually making this more concentrated in DDGS than in the corn itself, making DDGS corn, DDGS about the same concentrations, what we would find in soybean meal, wheat, having a little bit less at around 1200 milligrams per kilogram on an ASIS basis.
Dr. Ryan Dilger (00:22:36):
And then we can see how choline concentration of these four feedstuffs is quite a bit higher than we have for be a, the only exception here would be that of wheat, which has almost the same amount of be a as choline. But corn, DDGS and soybean meal all are virtually devoid of this. And so just putting some, some variability estimates on this, and our coefficient variation range here between five and 22%. So just highlighting that we have concentrations that are, that can be quite variable in this way if we think about these practical ingredients. Now, we can also juxtapose this with what are known concentrations in these same feed stuff. So I'm pulling up information from the poultry NRC again, last revised in 1994. This committee is currently convened right now, and we're again looking at choline and other important nutrients as part of poultry nutrition.
Dr. Ryan Dilger (00:23:28):
But what I'm highlighting in red here, these red bars would be the poultry NRC recommendation or how much is present in each of these different feed stuffs. And you can see for corn the analyzed concentration from modern samples that we've analyzed in just the last year, very similar to what was reported in the NRC, similar for wheat as well. But when it comes to corn, DDGS or soybean meal, the NRC level is shown here. We're at about 20% lower in what we've analyzed just recently. So it's unclear whether this is due to a change in genetics or other environmental factors that may be related to the amount of choline that's in these feed stuffs or even processing methods. But the poultry, NRC is suggesting soybean meal has around 27 2800 ppm, whereas it's analyzed now to be closer to 2000.
Dr. Ryan Dilger (00:24:15):
So about a 20% reduction from what we would expect it to have. And that's important when formulating this to make sure that we are meeting the choline requirements again. So for this reason, many nutritionists SW and poultry nutritionists may simply ignore the amount of choline that's coming in from feed stuff like corn and soybean meal. And certainly in, in the diet of, of every chicken, we're going to be including some form of choline as a supplement. So choline chloride is the predominant one that's available both in a dry and a liquid form. We can put in air quotes because we all know if we worked with choline chloride, just how hygroscopic it is. So even though it is dry, it's going to absorb moisture quite quickly. Other forms that are more minor in the industry would be choline by tartrate and choline citrate.
Dr. Ryan Dilger (00:25:00):
Both of these is, which along with cho chloride, are also used as human supplements. But again, in each of these cases, we're talking about a, a water-soluble form in providing free choline in these forms as opposed to that form of choline that we're getting through soybean meal in the form of phosphatidylcholine of being lipid soluble. So this all then relates to how much is present and how much, how bioavailable is it going to be, and I'll state that there are very few measures of true bioavailability in the literature when it comes to any species, animal, animal, agriculture, or otherwise. So some of this early work was done by my PhD advisor, Dr. David Baker at the University of Illinois. And my current colleague, j Jason Emerett, when he was at Illinois here they used a broiler model using soy protein isolate, or SPI.
Dr. Ryan Dilger (00:25:48):
So this is a, a type of soy that is virtually devoid. So it has been made almost having zero concentration of, of choline. So these soy protein is isolate based diets. Were also amended to include two amino, two methyl, one propanol. This is an inhibitor to prevent the de novo synthesis of choline. So both in the chicken to get enough, get it low enough concentration to look at bioavailability, we both had to formulate the diet with a low concentration and prevent their ability to, to have de novo synthesis. And in doing so, then they produced relative bioavailability estimates of soybean meal between 77 and 90% peanut meal, 70 to 80%, and then much lower here with canola meal. For our international folks, also known as grape seed, we're referring here to about 25 to 35% of the bioavailability, which is a third of that in soybean meal.
Dr. Ryan Dilger (00:26:43):
So in canola meal, the analyzed concentration is about three times higher and than soybean meal at about 6,000 milligrams per kilogram, but about a third lower the choline availability. And so this is an understudied area for sure, but this is likely related to the fact that we have significant concentrations of opine are a choline ester. And this phenolic compound is being analyzed along with choline. It's a choline ester, but it's going to be low available. So the chicken in this particular case does not have the ability to free that choline and use it as a source in its in its own metabolic needs. So the point here is that depending on the ingredient we're talking about and the processing methods that were used, we can have a very profound influence, both on the concentration of total choline and the different forms that are available, ultimately affecting the bioavailable content that's available to the animal.
Dr. Ryan Dilger (00:27:38):
Now, relating this back to, again, another important role of choline, this refers to its relationship with Bane. We can say that choline ultimately is the source of these labile or free methyl groups that can be obtained from Bane. And again, this is, is obtained through the conversion of choline into Bane through this two-step oxidation reaction. This is, again, an irreversible reaction, and you'll notice we look at the structure of beane, that it does not contain choline per se. What we've done here is we've oxidized this, this side chain. So this carbon now becomes a carboxylic acid from where it was had been a simple hydroxyl group. So it says beane that ultimately is going to rem methylate homocysteine to form methionine within the body. And again, we know that methionine is either first limiting for pigs or chickens, depending on the type of diets that we are feeding.
Dr. Ryan Dilger (00:28:27):
But this odent cell methionine is serving as the donator of methyl groups to literally hundreds of different, different methylation reactions within the body. So these include from a quantitative basis, we can think about methylation of DNA as part of epigenetics. We can think about the methylation of lysine to carnitine and lipid transport epinephrine to norepinephrine, and even gudino acidic acid being methylated to creatine. So this is going to relate to many different metabolic functions. And so again, choline serving as the first step towards the different pieces. But again, beane does not contain choline per se, which means that the provision or the, if we provide exogenous beane, dietary beane, can actually only spare one particular function of choline. And that is that of the, the methyl donation. So I'm gonna talk through how we can start to parse that out. But understanding that we have some species dependent considerations here that are, that are differing between.
Dr. Ryan Dilger (00:29:24):
So this then relates to effectively the ability for betaine to spare choline in various species. And this was a, a particular topic I had the opportunity to, to study as part of my PhD. So the constant, the concept here is that if we're looking at weight gain as our DeepEnd and variable, and we're looking at the amount of choline that's within the diet at some point, having started with a basal diet with which is deficient in choline by adding supplemental choline, we are getting an increase in the amount of weight gain up to a certain point where we reach a plateau. And it's at this breakpoint that we would identify as a mathematical estimation of the total choline requirement. So it's here that we say that we've met enough because our dependent variable and weight gain is not going up any further.
Dr. Ryan Dilger (00:30:07):
We've had this particular breakpoint. So the theory here, what we put forward is that the first two functions of choline, those being acetylcholine and phosphatidylcholine will be satisfied at 50% of the total choline requirement, and therefore we would get no beane response until that requirement had been met, per se. So we're referring here again to phosphatidylcholine and acetylcholine as having higher metabolic priority than beane in those three functions, ultimately of dietary choline. So the concept would be that only after we have met this ability for, for free choline to serve as the precursor to PC and, and acetylcholine could then betaine have the ability to increase body weight gain differentially. And so what we're thinking about is that this is going to then change this total choline requirement and shift this to a lower concentration, meaning that bane would be able to spare some of that of choline.
Dr. Ryan Dilger (00:31:05):
But again, it cannot fully spare all of this because these first two functions of phosphatidylcholine and acetylcholine require choline per se. So this was work that was published in 2007. We used a choline three purified diet in this case that contained adequate methionine and folate as well. So it was only deficient in choline in this particular case. And if we titrate this looking at body weight gain of chickens and looking at supplemental choline intake and milligrams on the x axis, we can get a nice titration up to a break point where we have defined then the choline requirement at 229 milligrams. For this particular set of birds, we can do the same by adding now supplemental bane on top of that diet. And so here we've added a Sufi amount at one gram per kilogram of supplemental beane.
Dr. Ryan Dilger (00:31:56):
We do the same experiment, and here now we get a breakpoint, which is much lower. So the choline requirement here was defined as 229 milligrams for broilers here in a in the diet without beane. And when we added beane in, that was 116. So the point was that beane in general could not spare choline in a choline free diet. So here at our lowest concentration, there were no difference between without and with bane. And if we take the concentration of the requirement here in the absence, in the presence and absence of beane that's 116 divided by 2 29. It's 51%. That fits with the theory that that preformed dietary choline is actually required for the first two metabolic priorities here in acetylcholine and phosphatidylcholine which would be expected at about 50%. So again, bane was only able to satisfy the remaining 50% portion of the choline requirement, again, as a donator of methyl groups, meaning that only all we're doing there is meaning that TA is taking away the, the need for choline to be oxidized into other Betaine.
Dr. Ryan Dilger (00:33:03):
So this is going to relate then to to swine and poultry species. With poultry having a relatively high dietary requirement, again, specifically for preformed choline, that's because they're lacking this particular enzyme, or they have an inefficient enzyme in the phosphatidyl ethanol, ethanol methyl transferase here. So their de novo synthesis is quite low, and if they can't convert it here to get choline, that means that we have to provide more of it in the diet. So this is leading to the higher concentrations or required in a, in a broiler diet than we would have in pigs. There's also evidence that we have a relatively high choline oxidase activity, which form favors beta formation. And that's important because betaine is serving here as an important osmolite to counteract the toxic effects. And this has to do with the, these species being uricotelic, so they're producing uric acid and in the avian kidney, we need the ability to buffer some of that through osmolite beane, along with with others, you're going to serve as important osmolite there.
Dr. Ryan Dilger (00:34:00):
And so, again, in the chicken, inadequate choline causes reduced growth and incidences of grosses and fatty liver as well. These are very classic conditions that we would be associated with getting insufficient choline. We also know that diets that are high in protein relatively increase the dietary choline requirement, and it's possibly because that's happening through degradation or use of that choline. And also point out that the activity of PEMT is going to actually increase with age, such that it's actually quite challenging to create a choline deficiency in birds after eight weeks of age. So this is mainly important in in starter diets and pre starter diets. Here we can think about the total choline requirements. These are being derived from the poultry N Rrc 1994 for broiler chickens for between seven 50 and 1300 milligrams for kilogram laying hens in a similar range. Only being different here based on the amount of feed intake that is being expressed by those animals. Turkeys and then quail. We also have actually a higher concentration in quail when put on a concentration basis in this regard. So again, this is not speaking to the form of choline, this is speaking to the total choline requirement in each of these species. But as we get into pigs, you'll see how much higher these concentrations are than what we're talking about in, in mammalian species.
Dr. Ryan Dilger (00:35:18):
So again, in pigs, lower dietary requirements, and this is mainly because they have more efficient PEMT activity and therefore more efficient de no photosynthesis of choline. Additionally, that choline in the, in the water soluble form can be obtained via the milk. And honestly, as they switch on to practical diets they're getting, they're typically getting enough from a corn soybean meal diet. So there's not much benefit in terms of growth for pigs that are consuming corn, soy based diets where methionine can effectively and completely spare choline its ability. There, the requirements here pulled from the swine NRC in 2012 relating to starter grower finisher pigs between 400 and 600. Again, that being about a third to a half of the concentrations, the dietary concentrations or requirements that are needed in chickens for gestating and lactating sows here, we're talking a little bit higher concentrations, again, as related to its ability or its its requirement as part of those early developmental pieces and being able to support the development of the fetus.
Dr. Ryan Dilger (00:36:17):
So higher concentrations there. And ultimately I'll talk about some of the concentrations in milk as well. But effectively, the south mom is providing some choline to the baby, to the piglet via the milk in that regard. So higher concentrations, I will point out that these requirements are actually, they were set in the 1940s, 1950s, and they have not been touched since. So if you look at the swine NRC 2012, we haven't really gone back and redefined what these requirements are with great changes in genetics in the pigs, and even changes in what we have in feed stuffs. So this is one part that I think that we need a greater emphasis on understanding what these are defining the, the proper outcomes for what is a deficiency in the pig, and being able to set those requirements in the modern genetics.
Dr. Ryan Dilger (00:37:07):
So as related to this, I just wanna bring forward some evidence recent evidence from my lab as we look at choline and choline status in the sow, and how this is relating not only to sow health and but also the, the production of milk and, and the support of health in the piglet as well. So there was some early evidence that higher choline may benefit reproductive performance of sows the stockland and blaylock work in 1974. So showing that higher concentrations of choline could increase the conception rate and increase the total born alive. So this relates to the efficiency of reproductive efficiency in that regard. And in fact, if we go to create a choline deficiency, we often wait until at least 30 to 40 days during gestation, because creating that deficiency early on can actually cause spontaneous abortion in cells.
Dr. Ryan Dilger (00:37:55):
So we, we looked at this question to understand how choline intake during gestation lactation is going to influence particular measures that are important for animal agriculture. And we've shown that it actually, that choline deficiency during gestation and lactation can actually change the composition of the s milk, not only of choline, but also of the amino acid and fatty acid composition of that milk as well. So this is relating, again, to the many different functions that choline is going to have, and the various areas, various areas within metabolism and the colon's involved. We can also change then the body choline concentrations and what form it's in. And I'll show a little bit of evidence on the metabolic profiles or metabolomic profiles. And ultimately this work was part of a, a series of studies where we were looking at brain development as using the pig as a biomedical model for humans as well in the study design. We did nothing to these sows after breeding, so after conception for 49 days but then 65 days before farrowing we would induce either a choline adequate or a choline deficient diet in the sows, but sows would then remain on that that particular diet through the postnatal period as well, where pigs were also tracked through 28 days. And we were looking at milk composition throughout.
Dr. Ryan Dilger (00:39:09):
So just highlighting some of this this earlier work first showing here perinatal choline status in sows. So on the left I'm showing plasma concentrations of choline containing compounds. Just to orient you, the first two bars here, we have sows, which were, so which were allotted to the choline adequate treatment versus the choline deficient. So CA and CD here are the, the abbreviations that I'll use. So first point is at gestation at day minus 65. So relative to farrowing, this is before we actually induced the choline deficiency. So this is just showing that in both groups, we had equal concentrations of the various forms of choline that are present within the plasma. So of note here in blue we have phosphatidylcholine. I'm saying that that is the predominant form that is circulating within the body. We also have sphingomyelin as the second most predominant, and we also have some beam here as well.
Dr. Ryan Dilger (00:40:00):
After those sos have been on a choline adequate or choline deficient diet for the last 65 days of gestation, and the entire duration of lactation here, now we're showing the plasma concentrations we're seeing a reduction but equal between those two. In certain forms, we're seeing an increase in the amount of phosphatidylcholine, and this was really because of a decrease in the amount of beam. So a reduction in the amount of circulating beam meant that phosphatidylcholine made a larger proportion of the total choline that was present there. So we've shifted within the sow based on the amount of choline that we've provided during gestation and lactation. So what's the pig getting from all of this? We can also look at the, the choline concentrations within milk here at lactation. This would be in colostrum, again, sows that were assigned to the choline adequate or choline deficient diet.
Dr. Ryan Dilger (00:40:49):
And remember that they've been choline deficient for two thirds of gestation. So here in colostrum, a couple things to notice. First of all, our blue bar here in phosphatidylcholine is now the minimum. So milk looks very different than plasma in this regard. Minimal concentration that's being provided to the animal. So those baby pigs are receiving this mainly in water soluble forms of choline. Here's glycerol phosphocholine in pink. We've got bingo, myelin, and we've also got phosphocholine. So those, along with free choline, we are then providing a much higher concentration of the free choline or the water soluble choline in milk. And we actually have a shift here between our adequate and deficient sows. So in large part, phosphocholine is going up, or glycerophosphocholine is going down. No real change in the amount of free choline, even though we are providing vastly different amounts of choline to these sows.
Dr. Ryan Dilger (00:41:45):
So what that tells us is that the sow is maintaining the concentration of choline to the, to the, the piglets via the milk at least in the colostrum to switch over to a lower fat content. Moving to day seven, day 18, we're seeing similar increases over time. But here we're seeing some differences again, between choline adequate and choline deficient sos in terms of their choline concentrations in the milk. And by 18 days of gestation, or 18 days of lactation here, now we're starting to see a larger concentration of beam in choline deficient sows. So again, just the different forms and concentrations of choline containing compounds that we're providing to the pig based on largely the gestational and lactational choline status of that sow. So this work went on to then understand if we had choline, adequacy or deficiency in the sow and the pigs born to those sows were then further stratified onto either choline adequate or choline deficient milk replacer.
Dr. Ryan Dilger (00:42:43):
These were pigs that were being artificially reared, so not receiving sows milk but either put on a similar plane of choline status, so either being adequate, adequate, or they were adequate in utero and deficient after they were born or the other direction they were deficient and adequate deficient deficient. So it gives, this gives us the four the factorial arrangement here of both prenatal and postnatal choline status being in these four orange, the dark orange here is going to be our adequate, adequate, that's our control all the way down to the dark blue and our deficient deficient. So some of the measures here, looking at liver weight, we actually see no difference between these different groups. This is liver as a percent of body weight again, going from our adequate, adequate to our deficient deficient, no real difference.
Dr. Ryan Dilger (00:43:28):
There's no hepatomegaly. So we're not getting an enlarging of the the liver in this way. However, if we look at the amount of liquid that's present in that liver, so same size, the proportion of body weight, but if we look at the acid hydrolyzed fat concentration of the liver in our control, animals in orange at about 4% or four, four grams per a hundred grams of liver on a dry matter basis, we go into our pigs that in utero were adequate and extra utero. They were born, they were deficient. We have a, a large increase in the amount of lipid accumulation that's being present here. So this, again, is a, a classic sign of a choline deficiency. And this effect is actually quite larger than what we have in the pigs that were deficient deficient. And so this speaks to the concept of metabolic programming, and that the environment that you are in, in utero is what you expect to also experience after you're born in that regard those pigs that were deficient prenatally were kind of expecting to be deficient postnatal as well, and actually don't have as much lipid accumulation in this regard.
Dr. Ryan Dilger (00:44:31):
The other point here is that those pigs that were receiving an adequate diet, those two in orange postnatally have a lower concentration of lipid as well. And so that then speaks into the me metabolomics part of this study where if we look at the total choline concentration, those pigs receiving a choline deficient milk replacer had lower concentrations of choline in general versus those that were adequate. But if we look at free choline and beane, these differences become even more stark. So the the prenatal concentration of choline, that which is provided to the sow actually doesn't have as much effect as what the, the offspring are going to be observing or, or consuming themselves. And so that's important because effectively the dam is sacrificing her own choline in order for the, the fetus to have adequate choline as much as possible.
Dr. Ryan Dilger (00:45:23):
So stark changes here in plasma metabolomics for GA related to these choline related metabolites. But this wasn't just choline that was affected. I'm only showing those related here. But amino acid concentrations, lipid fatty acid concentrations, and even carbohydrate metabolism were vastly changed simply by altering the amount of choline that mom or baby received in this regard. And in addition to liver lipid content, health marker biomarkers as well, looking at some of the liver enzymes that are present as markers of bio as biomarkers of health were also being elevated here in pigs that were receiving postnatal choline deficient diets. So again, relating to the liver is being relate, is being important metabolically and, and choline being part of that metabolism, this was an important finding. So just to conclude here, as we're kind of wrapping up just some take home messages, then I refer to choline as a, as a pervasive nutrient.
Dr. Ryan Dilger (00:46:22):
And this has to do with the multiple metabolic rules that it's going to play. And this is both, both prenatally and postnatally. And it, it cuts across different species as well. So there are species specific idiosyncrasies or differences in metabolism that ultimately are going to drive those requirements. And the, the takeaway here is that poultry species lack the ability to convert phosphatidylethanolamine into phosphatidylcholine en mass. So that means that they're going to have a higher dietary requirement for that, for for different forms of choline. We're also lacking considerably and analytical data of these choline related compounds, and that also relates to the amount of information we have about bioavailability of those forms as well. And so I think there needs to be a, a push to get more analytical data, data, both choline and beam, but looking at other forms of choline as well, and also understanding whether bioavailability how important it is and the form of bioavailability being phosphatidylcholine versus free choline.
Dr. Ryan Dilger (00:47:21):
What are the implications of that in terms of metabolic kinetics? And how do these vary by choline form? Now, I'll point out that the potential for choline deficiency remains a very practical issue, again, based on the concentrations of choline in our feed stuffs that we're doing, the bioavailability and the fact that we, we are going to have to continue to supplement these, especially in avian species. And I don't want to underestimate the importance here of Bane but show that it is distinct from choline. It is a derivative from choline but it cannot fully replace choline because at least acetylcholine and phosphatidylcholine have to be formed from choline itself. So we could have an entire other lecture on, on Bane and why it's important, especially in avian species. But again, a third very critical role, but one that cannot be spared when providing this, the diet. So with that, I would be happy to take any questions. I wanna thank everyone for your attention today and hopefully learned a little bit about colon. Thank you very much.
Scott Sorrell (00:48:22):
Oh, thank you, Ryan. Before we get started answering questions, we'd like to share a brief video, and then we'll be right back to answer the questions submitted during today's presentation.
Balchem VO (00:48:32):
Look to empirical choline chloride from Balchem to deliver the highest standards of quality backed by the strictest process controls for a level of purity, safety, and consistency you won't find anywhere else.
Scott Sorrell (00:48:44):
Dr. Dilger, your first question is how far can we go supplementing choline? This comes from Fernando choline above NRC requirements in order to be able to be safe against stress and management systems. I think we're talking a little bit about requirements there.
Dr. Ryan Dilger (00:49:03):
Yep, and it's a great question. And so choline by and large is, is a safe nutrient. The, the upper limit it would be very challenging to reach that upper limit in a, in a practical formulation. So it is safe to put plenty of of margin. So have a buffer there for the amount that you put in. But well above the requirement is, is not going to be an issue. And that's, that's a good strategy. Again, understanding that the concentration of the bioavailability and feed stuffs is going to be variable.
Scott Sorrell (00:49:27):
We've, again, another question related to requirement, and that is that the last NRC was what, approximately 27 years ago. Genetics and animals have changed significantly during that period of time. What impact do you believe that may have on the, the animals re requirement for choline?
Dr. Ryan Dilger (00:49:48):
Well, so I, I'm, I'm on the, the current poultry NRC committee, and we are certainly looking into those pieces and, and certainly you're, you're referring to the poultry, NRC being 1994 was a long time ago. So genetics have changed considerably. It's why we need to update the requirement estimates and I, there there's very little evidence, modern evidence as to what that should be updated to. But that is where we need additional evidence to understand how the requirements of the animals have changed, but also genetics in crops, how the concentrations of choline in the feed stuffs that we are providing to our animals have changed as well. So that's why there is a push right now to understand, again, concentration and bioavailability and the variance between different feed stuffs. But genetics is, is certainly a component and, and even health status is going to be something that needs to be taken into consideration when considering any nutrient. But here with the multiple metabolic roles that choline is going to play, I think is particularly important.
Scott Sorrell (00:50:43):
Very well, our next question is coming in from Carrie, considering how cheap choline chloride is, why should we ever care about the bioavailability content of major ingredients?
Dr. Ryan Dilger (00:50:57):
It's, it's a good question and again, that we as non remnant nutritionists are, are used to always providing choline in some form in, in a poultry diet. And so largely we've disregarded the amount that's coming in from from the soybean meal, for example. But we, we shouldn't disregard the different forms of choline. And knowing that choline chloride is, is a water soluble form, there are needs for phosphatidylcholine as well. So I think there's an understanding that it goes beyond just the water soluble form and we need to understand the lipid soluble form as well. But certainly cho chloride has been something that's, it's been in every poultry diet for a long time. We know how important it's, and, and, and how easy it is to supply. So that will continue, but understanding what's in feed stepss is also important.
Scott Sorrell (00:51:46):
All right. Our next question comes in from Justina. How does feed manufacturing specifically heat treatment affect choline slash beane availability?
Dr. Ryan Dilger (00:51:57):
That's a great question, and it's honestly, there's not any information out there in terms of you can think of examples of taking soybean meal that it's been under versus overprocessed in terms of its heating ability. I've not seen evidence that speaks to bioavailability there. So in bar, in large part there simply isn't enough bioavailability estimate out there evidence out there. And so that's something that I think we need to give more focus to.
Scott Sorrell (00:52:21):
All right. I'll ask my own question. We've recently seen some research from the University of Florida. This was in dairy cattle showing that the epigenetic effect of feeding choline to the dam had an impact on the, the health status of the calves as well as the rate of gain through two years of age. Any work done like that in, in swine or poultry.
Dr. Ryan Dilger (00:52:46):
So my lab's done some of that work that again, has more of a human context and understanding the epigenetics role, and that's where I presented a little bit of that but stayed away from most of the developmental pieces. So it does relate to early epigenetic effects, especially as we, we after conception, we're going to basically demethylate the entire genome and come back and we're going to use methylation as a way to either upregulate or downregulate gene expression. That's what we're referring to with epigenetics. So we're going, we're not changing the genetic code, but by using these methyl groups can change the phenotype. And we know that's important in pigs as well. And that was the basis for the prenatal and postnatal exposure to either deficient or adequate choline that we provided in cells. And I'm only showing some of the more metabolically focused outcomes, but that research goes on to look at neuroimaging outcomes, cognitive outcomes.
Dr. Ryan Dilger (00:53:39):
We know that choline early in life and in utero is going to have effects long term on learning and memory, cognitive performance, and otherwise there's no reason to believe that that's not also occurring in our agriculturally relevant species. But we simply don't focus on the brain in that regard. Where it comes into more play is going to be on the reproductive side and potentially with the immune efficiency of both mom and offspring as well. So it is important, I think that it's an area that's, again, understudied in both pigs and chickens there, there's a lot of room for doing additional research there.
Scott Sorrell (00:54:13):
Yeah. Now you've got quite a background in human nutrition. Maybe can you expound just a little bit more relative to the human side and, and the role of choline and cognitive ability epigenetics in in humans?
Dr. Ryan Dilger (00:54:26):
Yeah. There's some, some key researchers in that area Steven Ziel being one of them. You'll see his name on, on a lot of the work. But again, it's the recognition that it took until 1998 to actually define choline as an essential nutrient. And with that institute of medicine we, we still only had enough information to talk about adequate intakes. We know how important it is, especially for women before they know they are pregnant, because again, we're talking about very early developmental stages of fetal development. So it is important that women of childbearing age be getting enough choline before they're pregnant, just like with folate. And there's starting to be a recognition that we are doing folate supplementation and they have programs for that. Choline is starting to be a part of that. The challenge, as I understand it, is really about the supplementation on the human side.
Dr. Ryan Dilger (00:55:12):
And so they, they know more about the foods that humans are consuming in terms of their choline content. But getting choline into a pill form is challenging because it is at such high concentrations relative to other vitamins. So it takes up a lot of space in the formulation and that's why they're looking for the most efficient, most bioavailable form that can be put into that, such that the prenatal vitamin pill doesn't get physically large to swallow. So those are some of the, the implications, but it's certainly being recognized of the importance of choline and human milk and the variability between countries of women in each of those countries. And also then getting more supplementation programs going to ensure that we think of choline like folate as being important for those early developmental pieces, including neural tube defects that can occur if you don't have enough.
Scott Sorrell (00:56:01):
Excellent. next question comes from Michael. Have you looked at choline content and feed byproducts, example poultry and meat meal? Some work a decade ago suggested that these byproducts are nearly three times over predicted by the 1994 NRC.
Dr. Ryan Dilger (00:56:21):
Yeah, again, I think a lot of the information we have is quite old and that we need to, with the new knowledge and, and nutritional science, we need to come back and look at these different pieces. And it's not just the concentration, it's also the availability and the form that would be important there. But you would consider in a, a meat and bone meal as an animal source that there would be higher concentrations of choline. So I'd have to go back and understand more about what are the forms that are present. I worry more about variability in concentration which is going to then lead to differences in bioavailability as well. But again, it's, it's concentration form and availability are the three pieces we need to understand when ultimately on knowing how much to deliver to the animal and if we need to supplement beyond what's coming in via the, the ingredients.
Scott Sorrell (00:57:03):
All right. Our next question comes from Faye. Does choline levels during neonatal development have any long-term impact on the guilt and so life, productivity and longevity, or indeed a longer term impact on the performance of the progeny to slaughter?
Dr. Ryan Dilger (00:57:19):
I think the answer is, it's, it's highly likely, yes. Again, this is something that we haven't studied recently. We know that some of the work in the 1970s, 1980s was suggesting that higher concentrations would lead to better reproductive efficiency, and that was over three generations. So three subsequent farrowings in those sows. So there is the likelihood that yes, it would improve reproductive performance in terms of longevity. I don't know that those types of studies have been done taking those sows out long enough to understand if we're doing that part. So management styles going to come in as well. And it's not only choline that's affecting some of these other components. So choline is just one of the nutrients that's going to be important as part of it. But it's particularly important for some of these these functions that we're talking about here.
Scott Sorrell (00:58:08):
All right. The next question's interesting comes from Mr. Chen. Can you talk a little bit more about choline deficiency on animal behavior, especially on avian species? Is there any particular signs to look for?
Dr. Ryan Dilger (00:58:21):
Great question. One we have interest in, because again, we are, we're talking about optimizing animal health and, and the other side of my lab is dealing with use of the pig specifically as a biomedical model. So I can't speak to the poultry side. But knowing how important choline and beane are for the avian species, particularly because they have a higher dietary requirement we would expect that, yeah, it would be related to cognitive performance. We can show in pigs that a choline deficiency, either prenatal or postnatal alters behavioral outcomes as well. And so we mainly focus in my lab on the hippocampus, so where long-term memories are being stored. And that's because the hippocampus is a, a largely postnatal developing part of the brain. So if there's the ability for either mother's milk or a, a diet to affect that, it would be in this part. And we can show deficits in learning and memory in the pig which are similar to those deficits that are seen in humans not getting enough choline. So there's no reason to believe that similar deficits in cognitive performance learning and memory or other behavioral measures related to anxiety or otherwise wouldn't be affected in the chicken as they are in the pig and the human.
Scott Sorrell (00:59:30):
Alright. I got a couple questions related to biomarkers. What are the biomarkers used to measure the liver function regarding choline efficiency?
Dr. Ryan Dilger (00:59:40):
So these would be standard liver enzyme panels. If you think about A-S-T-A-L-T, you know, so we're, we're talking about enzymes that are present within the hepatocyte that when we have liver damage and with fat accumulation within the liver, we can get damage of those cells. We get rupture of those hepatocytes, which are releasing these enzymes, which are normally in the cytosol and are now circulating throughout the body. So in that regard, we're talking about standard standard panels if we're looking at clinical chemistry. And so amino aspartate so various enzymes that are present at within the liver and creatine kinase being another one of them. So a standard liver enzyme panel is what I'm referring to.
Scott Sorrell (01:00:22):
Alright. Thank you Ryan. Unfortunately, I see that we're at the top of the hour and that's gonna do it for today's presentation. So I'd like to thank Dr. Dilger and thank you everyone for attending today's webinar. If you have additional questions, please submit them to anh@marketing@balchem.com and we'll forward them to you along with the unanswered questions from today's session. On behalf of BAM and Dr. Dilger thank you for joining us today.
Balchem VO (01:00:48):
We'd love to hear your comments or ideas for topics and guests. So please reach out via email@anh.marketing at balchem.com with any suggestions and we'll work hard to add them to the schedule. Don't forget to leave a five star rating on your way out. You can request your Real Science Exchange t-shirt in just a few easy steps, just like or subscribe to the Real Science Exchange. And send us a screenshot along with your address and t-shirt size to anh.marketing at balchem.com. Balchems Real Science Lecture series of webinars takes place on the first Tuesday of every month with the top research and nutrition topics that will impact your business. We also include small ruminant, monogastric, and companion animal focused topics throughout the year. Visit balchem.com/realscience to see the upcoming topics and to register for future webinars. You can also access past webinars and search for the topics most important to you.