Good evening. My name is Mark Hedberg, and I'd like to welcome you all to this evening's webinar vet lecture. We're talking about, healthy gut, better biome, and I'm very, very pleased to be able to welcome Emma Short from Bailey's Horse Feed here for tonight.
Emma joined Bailey's Horse feed as an equine nutritionist after graduating from Riddle College with a BSC honours in equine science in 2002. Her role is varied, covering the provision of feed advice for general horse owners working on specialist feeding programmes for larger yards and professionals and providing technical support for the Bailey's sales and marketing teams. Emma enjoys applied and clinical nutrition, having seen plenty of changes and progression over the years within the industry.
She's keen to apply new research to the benefit of the welfare and the performance of the horse through Bailey's product development, as well as educational talks to horse owners, equestrian associations, veterinary practises, and retailers. And it's my pleasure once again to welcome Emma over to you. Thanks so much, Mark.
Thank you. Good evening everybody. So let's get started.
So maintaining your horse's digestive health is integral to maintaining their overall health and wellbeing. Digestive issues such as colic, ulcers, colitis and inflammatory bowel disease are some of the most commonly diagnosed health conditions in horses. So those who have an unhealthy gut, it, they could also sort of experience nutrient deficiencies or a lack of energy due to poor digestion and lower feed efficiency, which could ultimately result in poor performance, weight loss, poor condition, such as a dull, lacklustre coat, for example.
Behavioural changes may be seen and the risk of pathogenic disease may also increase. So unsurprisingly, nutrition is a major component of optimising the horse's stomach and hind gut health. So this evening, I'm going to discuss how and what you feed the horse, which can help to maintain a healthy gut environment and hopefully support the microbiome.
The design of the digestive system directly reflects how and what the horse has evolved to eat. So an inappropriate diet can affect the ability of the horse to perform to the best of its you know, the best of its ability. And understanding the digestive system's anatomy and its function will help to optimise welfare, performance and behaviour through nutrition, as well as supporting your advice and your recommendations to your clients and customers.
The horse is a herbivore by design. It forages by nature, moving and grazing vegetation for over 16 hours a day. Thus we know them as trickle feeders.
And we can divide the digestive tract into two parts. So we have the fore gut and we have the hind gut. The fore gut here comprises of the mouth, the teeth, the oesophagus, stomach, and also the small intestine.
With the stomach and the small intestine taking up less than 40% of the digestive system and the stomach being 10% of this. Food will start to empty from the stomach from the stomach as little as sort of 15 to 20 minutes after being eaten with smaller, sort of more liquid feeds, but can actually take up to 2 to 3 hours with more fibrous types of feedstuffs. You can see here you have the Margolicatus, which separates both the squamous or non-glandular and glandular regions of the stomach.
So the top squamous region is vulnerable to stomach acid as it is not naturally protected. And because of this, most gastric ulcers occur here along this Margo plaatus. The bottom glandular region contains glands that secrete acid but also bicarbonate and mucus which help to form a protective layer.
The horses continuously secrete gastric acid, whether there is food there or not, approximately 1.5 litres per hour. And this indicates that they should be eating almost continuously again, looking at that sort of trickle feeding effect.
The pH of the stomach, so how acidic it can be, can be more acidic depending on how the horse is fed or managed. So horses that are fastest, fastest, can't say that, fastest, sorry. And without forage for 4 hours or more, are at risk of stomach conditions becoming more acidic, as those are who are fed much higher starch-based feeds, which often goes hand in hand with those that are not fed adequate levels of fibre, such as, say, a competition horse, for example.
When horses were fed more than 2 grammes of starch per kilo of body weight per day, it was associated with an approximately 2-fold increase in the likelihood of them getting ulcers. And actually feeding more than 1 gramme per kilogramme of body weight of starch per feed was associated with just over 2.5 times the increase.
So choosing a concentrate feed that has a lower starch or cereal content and dividing the feed into much smaller portions may be beneficial. To naturally help defend against acid injury, we can ensure that our horses are fed plenty of forage, ideally to appetite where possible, and that they do not go for long periods of time without forage being available. Horses produce approximately half the amount of saliva when they're fed concentrates or bucket feed as compared to forage such as hay or pasture, which we would expect simply because chewing stimulates saliva production.
So it's thought that the saliva produced when chewing fibre has a buffering effect on the gastric acid. Forage also helps by providing a forage mat which you can see here in the diagram. And this helps to prevent acid from damaging the exposed square muscle top part of the of the stomach.
Fibre sources such as things like alfalfa can be useful as they are naturally higher in both calcium and protein, which again has been shown to help neutralise or buffer the effects of stomach acid. And a horse that's fed sufficient forage should ideally have this forage mat in place at all times, helping to reduce the incidence of acid injury during exercise, particularly. But offering a small forage meal such as such as a small amount of alfalfa prior to exercise can ensure that this mat is in place and may help to reduce the incidence of ulcers.
Oil in the diet can also help delay gastric emptying, which helps to control gastric acid levels within the stomach, as well as ensuring that digester entering the small intestine has a better chance of pre-cecal digestion. The small intestine is divided into three regions. You have the duodenum, the janum, which makes up the majority, and the ilium.
It's approximately 15 to 22 metres in length, with a 7 to 10 centimetre diameter. It's called the small intestine simply because it has a more narrow diameter, and this enables the food to come into contact with the gut wall, making it more easily absorbed and digested. Meal transit time is relatively rapid, with digester passing through the tract between sort of 45 minutes to 2 hours.
And this rate of passage in comparison to the hindgut is why so much attention must be paid to how digestible the concentrate feed is in particular. Feed that is not digestible or fed in to higher rates, increasing transit can pass through the through sort of undigested, resulting sort of in in hindgut dysbiosis or disruption. Which is not ideal.
Most of the protein, fats, carbohydrates are around 50 to 70% of soluble carbohydrates, as well as fat soluble vitamins and minerals are absorbed here. Bilele and digestive enzymes are released by the bile and pancreatic pancreatic duct, which opens into the duodenum, located at around sort of 15 centimetres from the pyloric sphincters from the stomach, so sort of around about sort of in this sort of location. One such digestive enzyme is amylase which breaks down starch.
So as horses have evolved to eat fibre, they produce comparatively little amylase compared to other animals, and so the digestive system has a limited capacity to utilise starch. Undigested or resistant starch that has escaped digestion in the small intestine passing into the hindgut is swiftly fermented by the residing microbes, which produces volatile fatty acids which are absorbed and used as energy by the horse. A fermentation product of these bacteria is lactic acid, which lowers the pH of the hindgut, rendering it, An unfavourable environment for many of the microbes that actually exist here, who generally favour a more neutral environment, and they can in some instances cause them to die.
So not only can this affect digestion, but it can affect the permeability of the gut wall releasing toxins and increasing the incidence of pathogenic bacteria to proliferate. Meal size is also very important in affecting how much starch is absorbed in the small intestine. And when meal size is too large, it accelerates the passage through the full guts, meaning there is less time for starch to be digested and absorbed in the small intestine, and a high incident incidence of it entering basically the hindgut, which we don't want.
So by feeding small feeds, ideally no more than 0.4 or 0.5 kg per 100 kg of body weight and per meal, increases the chance of starting other nutrients being absorbed in the small intestine and therefore reducing the risk of digestive upset.
Ideally, we want to be providing no more than that 1 gramme of starch per kilogramme of body weight per meal, or 2 grammes per kilogramme of body weight per day, but be mindful of feeding rates. So a low starch sort of feed designed to be fed in much larger amounts may not supply as little starch as you think. Ensure that any concentrate or bucket feed that you're feeding contains ingredients that have been effectively cooked and processed to improve that pre-cecal digestion.
This helps to avoid undigested material entering the hind guts. So moving on to the hindgut, which comprises of the secum, small and large colon and the rectum. The hindgut makes up around 60% of the digestive system and is the site predominantly of of fibre digestion, functioning best with a neutral pH of around 6.5 to 6.8.
Fibre has a complex structure and mammals don't possess the enzymes that are required to break it down. Instead they rely on, Billions, trillions of bacteria and other microorganisms like fungi and protozoa in the hindgut to break it down by microbial fermentation. So there are several byproducts to fermentation, including gas and heat, and fibre helps to push gas out of the gut, and a lack of fibre can result in gas related colics becoming more prevalent.
This is often a problem for older horses that are not able to consume enough fibre, possibly due to poor dentition. Digester sits in the secum for around 5 hours, passing into the colon where it can be digested for up to 72 hours, depending on its digestibility. So how much energy and nutrients that are supplied by the forage is dependent on how digestible it is.
Forages with higher levels of indigestible lignin, which gives the plant its structure, will not be as digestible and will take longer for the microbes to break down, so it's gonna be sitting in the gut for for longer periods of time effectively. Less digestible fibre sources such as later later sort of cut haze or straw, for example, will contain much higher levels of this lignified material, which is more difficult for the horse to digest and utilise the nutrients and energy available. This can result in material sitting in the gut for longer periods of time, which can reduce motility and increases the risk of impaction.
These types of horses can often have distended abdomens due to gut feel and gas being produced during sort of that fermentation as the microbes work at breaking it down. They may also have a higher incidence of free faecal water and will often struggle to maintain weight and condition which can again result in poor performance. So softer earlier cut hazel fibre sources such as alfalfa or sugar beets are great alternatives and are often preferable.
However, these types of fibre can be more fermentable in the gut, increasing gas production and may be higher in non-structural carbohydrates such as sugar, for example. So care may be needed for those that suffer from other clinical conditions such as laminitis, for example. Microbial fermentation produces volatile fatty acids like acetate and butyrate which are absorbed through the intestine and are then converted to glucose or fat for energy use or storage, making fibre one of the main energy sources for the horse.
Research has shown that diet type can affect the levels of different volatile fatty acids produced in different parts of the gut, with a high fibre diet producing significantly greater levels of butyrate and acetate in the large colon compared to a high starch diet. Butyrate is an important energy source for the cells lining the intestine. And production of this from fibre fermentation is key for maintaining the function of the intestinal barrier and supporting gut health.
So again highlighting how fibre is essential for optimum gut health. The bacteria that break down this fibre are also responsible for producing vitamin K and B vitamins such as biotin, which can be affected if the microbes are compromised. Microbiota has, you know, more than 100 trillion microorganisms and in general, there are sort of 5 types of microbes.
The first one you have your cellulitic or fibre digesting bacteria, your proteolytic bacteria which breaks down protein. Your lactic acid producing bacteria digesting starch, protozoa, which is there to produce your volatile fatty acids, and then you have your fungus and your yeasts which help to break down fibre also. Other bacteria will be there to produce B vitamins and things like your vitamin K.
So microbes are found throughout the entire digestive tract, but because most favour a pH neutral environment, nearly all inhabit the secum and the colon. So due to specificity to different substrates, the population of these individual microbes will vary by the type of food that is present in the digestive tract, so what we feed our horses effectively. Cellulitic or fibre digesting bacteria make up the majority of the bacterial population of the cecum in the colon, as you would expect, as this is the site of fibre digestion.
And your microbial populations can vary from one horse to the next. And this might explain why some horses can eat anything while others have digestive upset within the smallest change within their diet. Microbial balance involves keeping the numbers of cellulitic or fibre digesting bacteria as high as possible, and the lactic acid produces that digest starch as low as we can.
So if the lactic acid producing bacteria population starts growing. They produce enough lactic acid to influence the pH of the guts, making it less hospitable for the cellulitic or fibre digesting bacteria and more agreeable for pathogenic species. This is when problems may arise and how tolerant an animal is to changes in the pH before problems begin can be sort of highly individual.
Shifts in the bacterial populations can cause digestive dis you know, digestive upset. And an example would be when a horse normally consumes a high forage based diet and the amount of cereal or or starch is increased suddenly. So the number of cellulitic or fibre digesting bacteria will be high, but now there is more starch from cereal grains, which the lactic acid producing bacteria will start to work on.
The lactic acid producing bacteria starts to reproduce at an exponential rate and to keep up with the amount of starchs present, and increases in these bacteria will result in large amounts of lactic acid being produced and the pH of the environments dropping. So soon the pH will be too low for the cellulitic or fibre digesting bacteria to reproduce, so they start to die off. And as cellulitic bacteria die off, fibre cannot be digested efficiently.
The overall result has a negative effect on the microbial environment which may adversely affect obviously how the horse feels, but also, you know, how, how he's doing, how he's performing. So how can we support a healthy microbiome? Well, we need to prioritise fibre first.
So not only is it the primary fuel for the bacterial population, insufficient fibre can predispose or exacerbate numerous clinical conditions such as colic and gastric ulcers, emphasising the importance of fibre. We need to therefore ensure that our horses are receiving healthy levels of fibre. So we need to ensure that if forage cannot be fed to appetites, so fed ad lib.
I am due to possibly health conditions or when a horse is on an energy or calorie restricted diet, then a minimum amount of forage is provided, which is 1.5% of their body weight. And this is fed on a dry matter basis per day.
So dry matter is the amount of fibre and nutrients left. The water has been completely removed. So for example, if we're looking at a 500 kg horse, they would need a minimum of 7.5 kgs of forage per day on a dry matter basis, which in reality would equate to around 9 kg of fresh hay with a 15% moisture or water content.
It is important to ensure that more fresh forage is fed to account for the moisture content of each forage source, otherwise there will not be sufficient fibre in the diet to meet minimum dry matter requirements. Any change in diet will increase the risk of digestive upset. For example, the risk of colic is significantly higher two weeks after a diet change.
So consistency is key. Consider seasonal changes in forage. For example, spring grass is more digestible with a lower fibre content.
It will contain more nutrients, and non-structural carbohydrates such as sugar. It will also be higher in moisture or water compared to dried forages such as hay or haulage, which means the horse has to consume more in order to meet its fibre requirements. Make sure that you you make any changes to diet gradually and ideally over several weeks where you can.
Competition horses often are moved on to more easily sort of transportable forages like haulage. So again, if you cannot take the horse's normal forage with you when you travel, then make changes to it forage prior to him going so that there is not that sort of abrupt change. Those with limited appetites may not be receiving adequate fibre and therefore you may need to consider supplementing the diet with an alternative fibre source such as an alfalfa or a chaff, or, or sugar beets to ensure that adequate fibre is provided consistently.
If forage is not coming from a consistent source due to lack of storage facilities, which is quite common. Then again, forage can be changing frequently. So this not only alters the nutrient or energy availability, but it also, but also alters the digestibility of the forage to the, to the microbes, to the microbiome.
So how can we support and even influence gut health? Well, providing a variety of good quality forage and fibre sources increases the microbiota's diversity. So you might want to consider feeding a combination of fibre sources such as hay, grass, chaff and maybe a beat pulp, for example.
Reduce stress by making any dietary change gradually or not at all if you're able to. Keep meal size manageable so this helps to optimise digestibility. Again, remember that 0.4 to 0.5 kg per 100 kg of body weight per meal.
Be mindful of how much starch the the horse is receiving in each feed, but also on a daily basis. And consider supplementing with digestive enhancers. In the perfect world, our horses would have access to quality, digestible forage at all times.
They would not be subjected to stress challenges such as a change in forage or forage restriction. Environmental sort of diet, exercise, or routine changes or be subjected to clinical issues, etc. Etc.
So their gut would have a good diversity of microbes which are fermenting a consistent amount of metabolites such as our volatile fatty acids and vitamins, for example, to help maintain optimum health and metabolism. However, nearly all horses face daily stress challenges as we do as humans, which disrupts the balance of the microbiome. And there are differences between horses like people as to the diversity of the individual microbiomes.
So what microbes are present. So a stressed horse may not produce the ideal combination of these metabolites for optimum gut function. So the perfect world, as we all know, doesn't exist.
So why, why should you feed a digestive enhancer? Well, the horse is a hindgut fermenter and it relies on this symbiotic relationship with the microorganisms in the gut, to break down fibrous material to create these metabolites, so amino acids, vitamins, volatile fatty acids, etc. To be absorbed across the gut wall for energy and other functions.
A healthy microbiome is essential for digestive function, immune function, gut brain connectivity, behaviour, obesity and insulin dysregulation, to name a few. So changes to the horse's hind gut microbiome are associated with this sort of digestive upset or gut dysbiosis, linking with many clinical issues such as colic, colitis, equine metabolic diseases and laminitis. So what are digestive enhancers?
Well, as defined by the International Scientific Association for Prebiotics and probiotics ISAP. Prebiotics, so the food is a substrate that is selectively utilised by host microorganisms conferring a health benefit. Probiotics, which are the factory, are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.
And postbiotics, which is the product, is a preparation of inanimate microorganisms and all their components that confers a health benefit on the host, which is all a bit of a mouthful. So they all effectively are trying to do the same thing, which is to confer a health benefit to the host or the horse in this instance. So let's start with prebiotics.
So prebiotics are found in naturally occurring compounds such as those in plant cell walls. They are predominantly fermentable sugars, which the gut microbiome uses as an energy source, or they can modulate pathogenic microbes. So let's have a look at the two that we have here.
So we've got short chain fructoeligiosaccharides or POs, which is much easier to say. Which is a food or an energy source for the beneficial bacteria in the gut. It supports proliferation of good bacteria when the populations are challenged or if there is a lack of energy, and it increases the abundance of these good bacteria so that they can exclude pathogenic, you know, species or the bad guys through what we call competitive exclusion.
We also have Mananiligiosaccharides or moss, which is derived from yeast cell walls, and these are commonly fed as a prebiotic to aid the beneficial microorganisms present, but they also have pathogen binding properties, meaning that they bind to receptors on the surface of pathogens such as E. Coli, for example, and stop them binding to intestinal cells, which prevents the pathogens or the bad guys, if you like, from becoming established. They also have some microtoxin binding effects which is useful.
So supplementing with foss supplies energy for the good bacteria, which increases competitive exclusion, which then influences by both the microbiome and the microbiota. Fosts can increase the lactate utilising bacteria in the pre-sal digestive tract and in the large colon, helping to maintain a better pH and rate of fibre digestion. Studies have actually been seen to improve diarrhoea in foals and adult horses and a reduced incidence of colic and stabled horses.
So it's effectively a food source for the good guys, the good bacteria sitting in the gut. Two probiotics. So live yeasts commonly referred to as probiotic yeasts are single-cell organisms which are classed in the fungi kingdom.
There are around 1500 species of yeast known to exist, but the most commonly known one is sacromyiss aviae, which is used in the food and drink sector for its fermentation capabilities. There is, however, no bacterial probiotics approved for horses. In Europe and in the UK, so the only legal probiotic we can use in the UK is sacroyces servisa.
So how does it work? Well, the hindgut of the horse is often referred to as a fermentation fat. So the hindgut is considered anaerobic, so without oxygen.
However, small amounts of oxygen do enter via food or gaseous exchange in the bloodstream or the gut wall. Cellulitic or fibre digesting bacteria are very sensitive to this oxygen, and the fermentation of fibre can decrease or reduce. So yeast works by scavenging this oxygen, thereby helping to sort of maintain that anaerobic environment, helping to improve fermentation and fibre digestion effectively.
Yeast ferments when oxygen is not present, which improves nutrient digestibility and particularly with respect to fibre. It helps to promote efficient fibre digestion by increasing this cellulit or fibre digesting bacteria activity in the hindgut, which then outcompetes the lactic acid producing bacteria which we don't want. So this helps to reduce the amount of pathogen.
That are there. It helps to reduce the pH it helps to sort of prevent, sorry, the pH from from dropping. It also increases faecal pH increases forage intake and digestibility and helps to reduce stress impacts on the gut.
So relatively new on the scene, we also have postbiotics. So these are a combination really of probiotics, so yeast in this instance and prebiotics, which are being used together to produce metabolites via fermentation within laboratory conditions, as it would work basically in the guts. So the live yeast is then deactivated and dried, which.
What you're then left for, left with, if you like, is sort of your, your postbiotics, which consists of the whole inactive cells, any cell fragments which have been separated in the process and all the metabolites created during that fermentation process. Again, such as things like your volatile fatty acids, enzymes, vitamins, to, to name a few. So like probiotics and prebiotics, they may contribute to gut health and overall health.
So. If you were to give a horse a pro and a prebiotic, or one or the other, they would be subjected to different stresses or challenges such as what feed or supplements that horse is fed or maybe not fed. Varying forage qualities and availability, changes in grass pasture through sort of seasonal changes, individuals age, so if you've got an older or younger horse, that may affect, again, how well they can be utilised, medication or any illness that that horse is is going through or suffering or receiving, and they.
Will affect the microbiome differently for each horse and at varying times in their life. So although you improve the situation by feeding a pre or a probiotic and more metabolites are produced and gut health is improved, then you. Not feeding a pre or a probiotic at all.
These life stresses still have an impact, meaning that each time you feed a pro or a prebiotic, the number of metabolites produced will be will be different each time, and the outcome and the benefits will vary. So a postbiotic delivers a consistent combination of metabolites to the hindgut to support digestive health, joint health, immunity and exercise recovery. There's plenty of research ongoing and has been done over the years, but literature indicates that there's an improvement in immune function.
The microbiome is optimised and is more robust and stable during times of stress, helping to support good digestive health and fibre digestion. It therefore provides a more consistent source of metabolites that is the same each time they are fed regardless of any stresses that that horse might be facing at the time. This has a positive effect on the microbiome and has been seen to control appetite, may have anti-inflammatory properties, anti-carcinogenic properties, and has been seen to modify the environment within the digestive system and changes in the microbial composition.
As they are not living because they've been deactivated, they're also more stable and may withhold processing and manufacturing processes. More rigidly and transit through the digestive digestive tract is is good. So when would you feed these?
Well. As digestive health impacts so many areas of general health, there are many situations where pre pro and postbiotics may be beneficial. So these include but are not limited to some of these key situations.
So times of stress, so travel, competition, change of diet, changes of routine, if your horses are moving yards, or you have a new horse being introduced into the group, if your horse is suffering from illness or has, you know, has had antibiotics in the past, they may have. Droppings or signs of poor gut health, they may be losing weight. Senior horses that may have compromised dentition, so not taking in enough fibre or a compromised gut.
You may have a horse that's got a drop in or reduction in performance. They may be being fed higher starch-based diets, maybe with a restricted forage diet, and also following worming. So all of these, sort of times you can absolutely feed a digestive enhancer.
So which one should you feed? Well, prebiotics can be fed daily as part of the regular diet or as a supplement. Probiotics are often fed during, before, during and after periods of stress or illness or following antibiotic treatment.
Post-biotics can be fed daily as part of a supplement to provide a consistent or constant source of beneficial metabolites. But really, there are no right or wrong answers here. Your pre, your pro, and your postbiotics can be fed at any time and in any combination.
So a horse that has a compromised digestive system, in my opinion, would benefit from a postbiotic, as the microbes and the microbiome might not be as able to produce a consistent source of metabolites. Prebiotics and probiotics can also have, however, be beneficial as they both help support the existing population. And environment, meaning that the microbiome becomes stronger and healthier at the same time.
So potentially a combination of all 3 may be beneficial. What about other ingredients or supplements? Are they beneficial?
Well, there are many, as I'm sure you know, there are many ingredients and those that are combined within gastric or digestive supplements that may or may not help support a healthy gut environment. Efficacy can vary greatly and we may not fully understand yet whether these, or some of these ingredients are truly useful or how much we actually need for them to to work significantly. For me, it is important to concentrate on getting the base diet and management correct and then if additional support is required, further supplementation may provide a valuable extra.
As I'm sure you know, there are loads of ingredients and supplements, on that we could obviously discuss tonight, but I'm just gonna touch on a few which I think, may be beneficial. So we're gonna have a little look at alfalfa or lucerne, touch on pectin and can never say this, leticin and beta glucan. So, let's look at alfalfa initially.
So alfalfa is like Marmite, and if you're from the UK or visited the UK you'll know what I mean. And people either love alfalfa or they, they hate it. There doesn't seem to sort of be any in between.
So let's have a little look at why it can be controversial. Well, there have been studies that have been reported that feeding alfalfa chaff increases the incidence and or severity of glandular ulcers. So the first study looked at 70 weaned warm blood folds randomly assigned to a diet group.
The first was fed 3 kg of alpha. Alpha chaff Adly pay in a bucket feed. The second fed 3 kgs of alpha pellets, adlib pay and bucket feed, and the third was fed Adli pay and a bucket feed.
However, the bucket feed comprised of oats, which are higher in starch, at around 45%, soya bean meal and vitamins and minerals, and we do not know in what combination this was fed at. So the incidence of gastric ulcers increased from approximately 84% before weaning to almost 100% after weaning in all groups, with the majority of ulcers found in the glandular region regardless of diet. However, the severity of the ulcers at the exit of the stomach was greater in foals that were fed the alfalfa chaff, but it was unclear whether the Increasing glandular ulcers was the result of mechanical damage caused by the harsh harsh nature of the alfalfa, or by a breakdown in the stomach linings defence system caused by the stress of weaning.
So for this reason, the same group of researchers completed a second study with adult horses, but unfortunately the results were inconclusive. The texture and the length of alfalfa chaff can vary significantly. And the alfalfa chaff fed in both studies was described as harsh, and therefore the increase in glandular ulcers could have been the result of mechanical damage as suggested obviously by the researchers.
In the first study, for example, glandular ulcers increased significantly at the pyloris, which is an area that may be particularly susceptible to mechanical damage. The degree. And or the risk of mechanical damage may also be influenced by the amount of alfalfa fed.
And actually in both studies, alfalfa child was fed at relatively high levels. So in the first study it's 3 kg, and in the second study, it was equal to around 7.5 kgs per day for a 500 kg horse, which we would typically not feed over in the UK.
That's, that's quite high. Currently there is insufficient evidence to suggest that we should not feed alfalfa. With many still recommending it.
So there are lots of positives to alfalfa, so it's important to remember that alfalfa increases chew time. It produces more saliva, thus neutralising the stomach acid, as most, you know, as any fibre does. It also has a higher protein and calcium content, which actually helps to sort of increase the buffering capacity which is beneficial.
And in fact, there have been several studies that have found feeding alfalfa alongside or part of the bucket feed provides a projective effect against ulcers. So let's look at pectin. So pectin is a type of fibre found in many fruits and vegetables, including sugar beets, which is what we use within our horses' diets frequently.
It acts as a prebiotic in the hindgut supporting the growth of the beneficial microbes within the, within the gut, and it's degraded by these microbes. To produce these volatile fatty acids or as an energy source, helping to maintain that healthy microbiome. Also in acidic conditions like the stomach, pectin alters its structure to one that is similar to mucus, and it has been shown to bind to and thicken the stomach mucosa and in the presence of surfactants such as leicin, the effect is enhanced.
So leticin is a naturally occurring phospholipid commonly derived from soybean or sunflower in horse diets. It forms a phospholipid layer in the squamous region of the stomach which acts similarly to the protective mucusus that is naturally present in the glandular region of the stomach. The combination of both pectin and leticin can be beneficial for digestive health in horses and can help protect the stomach lining against gastric ulcers.
So studies have shown that supplementing horses with both pectin and leticin may may aid ulcer healing. You might want to consider sort of, you know, beat based feeds or those that maybe contain soy oil to to to maybe get some, some of those benefits. Beta glucans.
So in equine nutrition, beta glucans are primarily primarily sort of included for their functional properties rather than as nutrient sources. And they're a group of soluble sort of dietary fibres found in the cell walls of cereals such as oats and barley, as well as yeast, fungi and some types of algae. And from cereal sources, it can create a hydro gel which helps to moderate the transit.
Of starches through the gut, which helps to optimise digestion within the small intestine, which is what we want. It has been shown that beta gluten can also reduce the glycaemic peak by about 50% after a meal, which again can be beneficial in some clinical issues. And yeast derived beta glucans are commonly added to supplements for their potential immunomodulatory effects.
And these fibres may help support the intestinal barrier. And help stimulate aspects of the immune response. However, studies have used various beta glucan dosages in horses ranging from 10 milligrammes per kg per day, per kilo of body weight per day to 170.
And therefore I think it's fair to say that possibly more research may be required to fully understand its benefits and how much we actually truly need for it to be beneficial. Although digestive health supplements can be a great addition to the diet, for me the most valuable advice is to ensure you are also making the right management and nutrition choices. So ensure that you're feeding forage to appetite where possible.
If you can't feed forage appetite because you're having to limit it for whatever reason, make sure that you're feeding a minimum of that 1.5% of body weight as dry matter per day, and adjust your fresh weight amounts accordingly. Avoid periods no longer really than 4 hours without any forage.
Try and ensure, try and give your horses access to turnout, ideally consistently, so every single day where possible. And a variety of fibre sources can help to increase that microbiota diversity as well as provide more enrichment for our horses. So consider different fibre sources in your diet consistently.
To, to improve that. Feed little and often, so small feeds throughout the course of the day. No more than that 0.4 0.5 kg per 100 kg of body weight per meal.
Avoid making sudden changes to the diet. Changing, any diet, you should be looking at a minimum of 10 to 14 days, possibly longer if you have a horse that's particularly sensitive. Consider seasonal changes.
Consider when you're changing from. A different batch of hay or hailage. All of that is changing the diet.
So we tend to forget the forage portion of the diet when we talk about changing, the diet. Minimise starch intake. Ensure there's plenty of access to plenty of fresh water.
Water's really important not only for hydration, but it's really important to help motility and keep everything moving throughout the tract. Monitor changes and droppings, so look to see whether they're loose, how, you know, How are they breaking up when they fall to the ground? How many droppings are your your horses doing?
So keep in check what's normal for your horse. Regular dental checks are really important, particularly for the young horse and the older horse, as they may not be able to chew or digest fibre as efficiently if they've got issues with with teeth. You may need to look at alternative forage sources if that is the case, forage, partial forage replacements.
Ensure that you're feeding a fully balanced diet that provides sufficient antioxidant support. So antioxidants like vitamin C and E can positively impact gut health by supporting the microbiome and potentially reducing inflammation and potentially feed a digestive enhancer. There's plenty of studies to prove that they really can be effective.
And that brings us to a close. So thank you so much for listening, and I look forward to any questions that you may have. Thank you very much, Emma, really enjoyed that one.
We've got some excellent questions here, so ready or not, here we come. Right, so first question from Malina Margarinos, are pre, pro and postbiotics protected from low stomach pH like bypass fats? Right, yes.
So prebiotics will, yes, they are, they will only be digested, and there has been research to prove that they will go into the hind gut. Yeast is a little tricky, a little trickier, and we quite often, particularly when we're processing, and we're putting yeast within, within the feeds ourselves, you can get. Yeast.
So you have the live yeast which is then protected by or encapsulated if you like with dead yeast so that you will have a more sort of effective dose once it hits the hindgut and postbiotics absolutely, they're already dead so we don't have to worry about, you know, them being affected by by gastric acid. Right, thank you very very much. Next question.
Intrigued by so many stressors on sport and leisure horses, and any interaction between pre and postbiotics with antacids, which are increasingly used. Yeah, antacids are not, not, I don't know whether there's an interaction between them. Antacids, yeah, absolutely can be used.
I think for me, and looking at the studies that are available, antacids are sort of quite short-lived. So, yeah, of course they, they may help in the interim, but maybe a long term sort of effect it may not be as beneficial, as we like. For me, I think looking at fibre, almost as.
An antacid, if you like, particularly for those that maybe have high levels of calcium, for example, may be more beneficial because you're getting a combined, result. You you're increasing 2 time, you're increasing saliva production. You've also got that benefit of things like your calcium.
Beet pulp is also . Quite a good calcium source so that can also be beneficial. And then obviously you also have the, you know, the, the benefits of it changing within that sort of that that acidic environment.
So yeah, the interaction between the the digestive enhancers and the antacids I'm not sure about, but antacids, yeah, they have their place, but I think maybe there are more long term, sort of options that you can that you can provide. Lovely, thank you, thank you. And speaking of sugar beet, our next question, does sugar beet cause a significant glycemic peak?
It depends on whether it has molasses incorporated within it. So, to my knowledge, and I'm please feel free to correct me. I don't, I don't believe it does.
It's effectively forage, it's it's effectively very high levels of pectin. If it has slas. Is incorporated within it, so obviously the sugar levels will absolutely then yeah, your glycemic response will will will absolutely be be different to the unmolassed versions.
We use beets and there's been lots of studies to suggest that beet is really useful for those that have, sort of, you know, clinical issues such as metabolic issues, laminisis, etc. So we deem it to be, you know, reasonably safe to feed. As long as he's on the last.
Fair enough. No, thank you. And, next question here.
So what is the difference between brewer's yeast and a probiotic yeast? Do they work? Ah.
Yeah, there is a difference, absolutely. So brewer's yeast is is basically dead yeast. You could almost say that it's a postbiotic, if you like, because it's deactivated it's dead yeast.
It, however, doesn't supply that consistent source like a specific postbiotic, so it will vary. A probiotic yeast is, is alive, so it's, it's very different. So they, they have very different actions, on the, on the, on the sort of the hindgut or the digestive system.
So your probiotic yeast is, is alive, so you're adding sort of more yeast, if you like, to the gut, whereas your brewer's yeast is, is already dead. So it's, it's almost a little bit like a post. Whereby you're, you're almost using it as a food source, if you like, for the existing microbes with within the guts.
Lovely, lovely. Thank you very, very much there. A couple of questions of my own I wanted to add in just a quick note here for everyone else.
We still have time for a few more questions. So if you'd like to add some questions to our Q&A, then we're very happy to answer them in the time remaining. I just see there were a couple of of hands raised.
So anyway, a question on my own. There was, in the early part of the lecture, there was a little bit about how oil would delay the gastric emptying, I think it was, and was there any particular oil that's that's recommended? Does it matter?
Not that I know of. There has been a couple of studies that suggest that corn oil is maybe the, the oil to go for. .
For me, I don't think there is any conclusive evidence either either which way. One study was suggesting sort of quite small levels. I think it was about 30, I think it was 30 mil off the top of my head, thought that that was beneficial, whereas another study fed significantly higher levels, I think possibly even up to 250 mL, and they saw no significant difference within their research.
So, Yeah, I, I think maybe the jury is out. There may be some some research that I have, I'm not aware of, but yeah, I mean corn or possibly, but to my understanding, just oil in general, you could also argue that maybe soy oil could be beneficial because you've got the, you know, potentially the the. Sort of, you know, coming in there.
So yeah, I'm not 100% certain on that, Mark, but yeah, corn oil is certainly one of those oils that tends to get bought up and and there has been a couple of research papers, on gastric ulcers with respect to that. If someone's worried about too much oil making my horse fat, do they have to worry? Yes.
Yes you do. It depends on how much you're feeding. If you're only feeding sort of 30 to 50 mL a day, you don't have to worry.
As soon as you start feeling higher levels, and particularly it's more, it's more of the issue when you've got a horse that's on a restricted calorie energy based diet. If you're restricting forage and restricting everything as much as you possibly can because you're trying to reduce weight loss, then obviously adding higher levels of oil into the diet can absolutely increase calorie and energy intake, so it can have a significant effect. But as I say, if you're only feeding sort of a glug or a tablespoon or sort of meal, yeah, you're, you're good.
OK. What would you consider the most frequent, what's the most, the most frequent digestive disorder you'd see on, on a horse that then. That's a tricky one.
I mean, if you're bringing in things like metabolic disorders and things like laminitis, I think that's pretty up there really. Colic obviously is one of those that, that sort of, you know, it's and and seasonally is is intermittent as well. From my perspective, we see less of things like, IBD or colitis, but yeah, certainly the metabolic sort of issues, loose droppings, and that, and that usually does come to obviously that quite often there's an, there's an issue possibly with the fibre, fibre sources changing, you know, digestibility can, can be sort of quite, can be quite an issue there on frequently for us anyway.
A new question coming here. Are there specific management recommendations for horses suffering from free faecal water? Yeah, that's a tough one.
I suppose the main thing from my point of view, is to make sure that the forage that you're feeding is as digestible as it possibly can be, if you can feed digestible forage. So be aware if there are other clinical issues there as well. Maybe watch out for sort of sugar levels, etc.
Too. But, but forage that's as soft and as digestible, so it's been harvested if you're feeding hay or hailage, it's been harvested much earlier on in the season. Ideally it should be nice and soft to touch, have a higher leaf content, and that means that it will not sit in the gut for for long lengths of time, which is beneficial.
Looking at sort of providing different sources of fibre. So beat pulp is actually really a it's a it's a great ingredient to help support sort of those those microbes sitting in the guts, and also looking at maybe a digestive enhancer to to support sort of obviously fibre digestion. Unfortunately, I don't think there's any specific, I mean, you, you might, you might know differently, Mark, but I, I don't need anything specifically that works, you know, all the time for, for every individual.
But I think the fibre for me is key and, and, and supporting and maintaining a, a good microbiome with those digestive enhancers is, is key. Mhm. OK.
No, thank you very, very much there. Question here, question on postbiotics, just slightly. Do you have any particular favourite postbiotics?
Yes. I suppose everyone does. Yeah, I don't know whether I can, whether I can say, you know, we, we, we, we can pass slightly over that no word, never mind.
I didn't ask. There we go. But yeah, yeah, I mean, look at the debate.
You can look at our, you can look at our our website. Speaking of your website, I must admit, one of my favourite ones, I just put the link in here on the website, you've got this little, cartoon, which cartoon is your horse? And I just I just thought that was absolutely brilliant.
Yeah, absolutely, yeah, the skinny one, the fat one, the zen one. Yeah, absolutely. A picture for all.
Yeah, listen, I just want to say once again thank you very much for the the webinar this evening. We had some wonderful questions here. It was a big turnout here, for everyone who's, been watching, this will be available on the webinar that website from the next business day or so.
And you'll, you'll be notified, of course, CPD certificates available in 24 hours as well. Thank you, Emma, thank you very much and Rebecca and then the rest of the team for organising this and looking forward to seeing you in a future webinar.
