The art and science of feeding horses prone to gastric ulcers

Words - Sarah Nelson

Risk factors for squamous or ‘non-glandular’ ulcers are well documented and include low forage diets and long periods without eating, diets high in non-structural carbohydrate (NSC) or ‘starch and sugar’, intensive exercise and stress, as well as prolonged periods of stabling and travelling. While some risks may be unavoidable for racehorses in training, diet is one that can be influenced relatively easily. 

In this article, Nutritionist, Sarah Nelson, discusses some of the science and provides practical advice on the nutritional management of horses prone to non-glandular ulcers. While glandular ulcers may be less responsive to changes in diet, the same nutritional management is generally recommended for both glandular and non-glandular ulcers. 

Evidence that diet makes a difference

Research published by Luthersson et al (2019) was the first to show that changes in diet can reduce the recurrence of non-glandular ulcers following veterinary treatment. In this 10-week trial, fifty-eight race/ competition horses were paired according to their workload, management and gastric ulcer score (non-glandular ulcers graded 0-4). One horse from each pair continued with their normal diet while the other had their normal ‘hard feed’ replaced with the trial diet which was divided into three equal meals. Horses with grade 3 and grade 4 ulcers were also treated with the recommended dose of omeprazole for four weeks. All horses were scoped at the start of the trial, immediately after omeprazole treatment had finished and 6 weeks after treatment had stopped. 

The majority of horses improved as a result of omeprazole treatment regardless of diet. Diet had no effect on grade 2 ulcers. At the end of the study, gastric ulcer scores in the horses that were fed the trial diet were not significantly better or worse than in horses that were not fed the trial diet. Overall, gastric ulcer scores in horses that were fed the trial diet remained improved 6 weeks after treatment had stopped. Six weeks after treatment had stopped, gastric ulcers scores had worsened in the majority of horses that remained on their normal feed so that overall, there was no difference between pre and post treatment scores.  

Importantly, this research shows that changes in diet can help to reduce the risk of gastric ulcers recurring after treatment, even if other changes in management are not possible. There was also no apparent long-term benefit of omeprazole treatment alone, highlighting the importance of other strategies in the long-term management of horses prone to gastric ulcers.  As this study only evaluated changes in ‘hard feed’, it is possible that greater improvements could have been achieved if changes to forage were also made. 

Recent research reveals unexpected results

Regular turnout often isn’t possible for horses in training and while the risk of gastric ulcers generally seems lower in horses at pasture, recent research carried out in Iceland by Luthersson et al (2022) has highlighted this may not always be the case.

In Iceland, horses typically live out at pasture, often in large herds and if stabled, they are generally fed a high forage, low starch and low sugar diet. While Icelandic horses do get gastric ulcers, it’s been suggested that the over-all incidence is low. 

The aim of this study was to investigate the incidence of gastric ulcers in Icelandic horses moving from pasture into light work. Prior to the study, all horses had lived out in large herds for their entire adult lives (age range 3-7 years), had never been in work and were fed supplementary forage in winter months only. All horses were scoped within two weeks of being removed from pasture (prior to starting ‘training’) and were scoped again approximately after 8 weeks of being stabled and doing light work. Most horses were fed forage only during the training period, but 11 were given very small amounts of soaked sugar beet and 3 were given a small amount of commercially produced feed. However, in all cases, starch and sugar intake from ‘hard feed’ was equivalent to less 250g per meal for a 500kg horse which is well within the current recommendations for horses prone to gastric ulcers.

Approximately 72% of horses had non-glandular ulcers (grade 2 or above) at scope 1. The prevalence and severity of gastric ulcers improved after eight weeks of stabling and light work - approximately 25% of horses had non-glandular ulcers (grade 2 or above) at scope 2. Horses given forage three times per day as opposed to twice per day were almost 18 times more likely to improve! Over-all, the incidence of glandular ulcers decreased from 47% to approximately 41% 

The high prevalence and severity of non-glandular ulcers at the start of the study, and the subsequent improvement following the training period was unexpected. Not only is this research an important reminder that horses at pasture are still at risk of gastric ulcers, it highlights the importance of regular forage provision. 

Forage focus

Forage is critical for mental wellbeing and digestive health in all horses but sometimes receives less attention than ‘hard/ concentrate’ feed, particularly for performance horses. When it comes to reducing the risk of gastric ulcers, one of the main benefits is promoting chewing. 

Saliva provides a natural buffer to stomach acid but unlike people, horses only produce saliva when they chew, which is why long periods without eating increase stomach acidity. In one study, the risk of non-glandular ulcers was found to be approximately 4 times higher in horses left for more than 6 hours without forage, although the risk may be greater during the day. 

Research by Husted et al (2009) found gastric pH drops in the early hours of the morning, even in horses with free access to forage. Not only do horses generally stop eating/ grazing for a period of time during the early hours of the morning, they are normally less active at night, reducing the risk of gastric splashing.

It should also be remembered that forage is a source of fuel – even average hay fed at the minimum recommended amount may provide close to 45% of the published energy requirement for a horse in heavy exercise. Forage analysis can be a useful tool, especially if you can source a consistent supply. 

Routine analysis normally includes measuring / calculating the water, energy and protein content, as well as providing an indication of how digestible the fibre is - more digestible forages yield greater amounts of energy and can help to reduce the reliance on feed.

Minimum forage intake

Ideally all horses, including racehorses in training should be provided with as much forage as they will eat. However large amounts of bucket feed, intense training and stress can affect appetite so voluntary intake (how much is eaten) should be monitored wherever possible. 

In practice, this means weighing the amount of forage that’s provided, as well as any that is left in a 24-hour period.  Ideally, total daily forage intake should not be restricted to less than 1.5% bodyweight per day on a dry matter basis, although an absolute minimum of 1.25% bodyweight (dry matter) is considered acceptable for performance horses, including racehorses in heavy training. 

On an ‘as fed basis’ (the amount of forage you need to weigh out), this typically equates to (for a 500kg horse without grazing):

  • 9kg of hay if it is to be fed dry or steamed (or an absolute minimum of 7.5kg)

  • 11-12kg* of haylage (or an absolute minimum of 9-11kg*)

The difference in feeding rates can cause confusion but essentially, even unsoaked hay contains some water and the water doesn’t count towards the horse’s forage intake. 

*based on a dry matter of 65-70%

How much starch and sugar is ‘too much’?

The fermentation of starch by bacteria in the stomach results in the production of volatile fatty acids which in conjunction with a low pH (acidic environment), increases the risk of ulcers forming. Current advice, which is based on published research, is to restrict non-structural carbohydrate (NSC) or ‘starch and sugar’ intake from ‘bucket feed’ to less than 1g per kilogram of bodyweight per meal and ideally less than 2g per kilogram of bodyweight per day. For a 500kg horse, this is equivalent to:

  • Less than 500g per meal 

  • Ideally less than 1kg per day

Traditional racing feeds are based on whole cereal grains and as a result, are high in starch. By utilising oil and sources of highly digestible fibre such as sugar beet and soya hulls, feed manufacturers can reduce the reliance on cereal starch without compromising energy delivery. 

Meal size matters

There are several reasons why horses should be fed small meals but one that’s of particular importance to managing the risk of gastric ulcers is reducing the amount of starch and sugar consumed in each meal. 

Large meals may also delay gastric emptying and in turn, lead to increased fermentation of starch in the stomach, especially if cereal based. Restrict total feed intake to a maximum of 2kg per meal which is equivalent to approximately 1 Stubbs scoop of cubes.  

Feeding ‘chaff’ to prevent gastric splashing

The horse’s stomach produces acid continuously (although at variable rate). Exercise increases abdominal pressure, causing acid to ‘splash’ onto the stomach lining in the non-glandular region where it increases the risk of ulcers forming. Exercise may also increase acid production.

Feeding short chopped fibre helps to prevent ‘gastric splashing’ by forming a protective ‘fibre mat’ on top of the contents of the stomach and may be of increased benefit to horses on restricted forage diets. Current advice is to feed 2 litres of short chopped fibre volume – equivalent to 1 Stubbs scoop – within the 30 minutes prior to exercise. Ideally choose a fibre containing alfalfa as the high protein and calcium content is thought to help buffer acid.

Supplements safety & efficacy

Supplements are often an attractive option, with owners and trainers from various disciplines reporting benefits. Unfortunately, scientific evidence is currently limited with some studies producing conflicting results which means specific recommendations regarding the optimum blend of ingredients and recommended daily intakes have not been established. 

However, ‘ingredients’ that may help to support gastric health include pectin and lecithin, omega 3 fatty acids, fenugreek, threonine, liquorice and maerl, a marine derived source of bioavailable calcium. But don’t forget, there are some important safety considerations, both for horse health and mitigating the risk of prohibited substances. 

  • Supplements should never be used as an alternative to veterinary treatment or an appropriate diet.

  • Beware of bold claims – if it sounds too good to be true it probably is!

  • It is illegal for manufacturers to claim products can cure, prevent or treat gastric ulcers. Words like ‘soothe’ and ‘improve’ are also prohibited. While bold or illegal claims do not automatically mean a supplement presents are unsafe, it does raise questions over the company’s ethics. 

  • Speak to a nutrition advisor before feeding supplements containing added vitamins and minerals as some can be harmful (or even toxic) if oversupplied.

  • Avoid supplements (and feeds) containing added iron.

  • Be cautious of supplements containing iodine, including naturally occurring sources such as seaweed.

  • Ensure the total diet provides no more than 1mg selenium per 100kg bodyweight (5mg per day for a 500kg horse).

  • Natural does not always equal safe – avoid herbs of unknown origin.

  • In the UK, use only BETA® NOPS (British Equestrian Trade Association, Naturally Occurring Prohibited Substances) approved feeds and supplements.

  • Only use supplements produced by an authorised feed manufacturer (supplements are classified as feeds in the UK and the EU and regulated by the same legislation). Approval numbers must be included on the label but knowing what to look out for can be tricky. That said, any supplement carrying the BETA® EGUS approval mark will have been produced by an authorised manufacturer.

The BETA EGUS approval mark 

Although they are by no means the only suitable option, you can be assured that feeds carrying the BETA® EGUS approval mark have been through a rigorous independent review process to ensure:

  • The combined starch and sugar content is less than 25% for high energy feeds and less than 20% for low-medium energy feeds

  • They provide less than 1g of starch and sugar (combined) per kilogram bodyweight per meal when fed as recommended

  • No inaccurate or medicinal claims are made on the packaging or in marketing materials

  • The feed is correctly labelled

  • It fulfils the nutrient specification – this includes independent laboratory analysis

Full references for scientific research available on request.

Fuelling the racehorse - time for a paradigm shift!

Article by Dr Katie Williams

What does it take for received wisdom to be overturned and new approaches adopted? Revelatory research findings? Social demand for change? Both could actually result in a change to the way racehorses are fed today as welfare and sustainability in equestrian sport are increasingly scrutinised and researchers find ways to feed and manage horses more sympathetically and sustainably. 

Can we feed a racehorse more sympathetically - evolutionary considerations 

The horse is a herbivore and as soon as we prevent them eating as they have evolved to do, there are repercussions for their health and well-being. The increasing frequency with which ulcers are being diagnosed may account for why the recommendations for the minimal amount of forage a horse requires has increased in recent years. Rendle et al. (2020) cite 1.5% of bodyweight on a dry matter basis which is the level most equine nutritionists would advocate for the long-term health of the horse. 

The glandular region of the horse’s stomach contains glands that secrete hydrochloric acid, pepsin, bicarbonate and mucus. The stomach secretes acid continuously; as the horse is a trickle feeder it has evolved to do so continuously and it is important to note that this process continues even when the horse isn’t eating. This is why periods of more than 6 hours without access to forage are a risk factor for ulcers. The volume of secretion has been shown to be around 1.5l of gastric juice per hour although this does vary at different times during the day. Consuming too little fibre and eating materials that are high in starch, means acidity levels increase in the stomach. This not only increases the risk of ulcers but also changes the environment in the stomach sufficiently to impact the microbes that live there. Microbial dysbiosis in the stomach is increasingly being linked to an increased risk of gastric disease, particularly in the glandular region which is now recognised as an inflammatory disease rather than an ulcerative one.   

There are other potential health issues to consider too. It has been shown in trials in mice for example, that a low fibre diet increases the permeability of the gut – a phenomenon known as leaky-gut syndrome. When fibre is fermented in the hind gut, one of the volatile fatty acids produced is butyrate and this is the energy used by the colonocytes (gut cells) themselves. Insufficient fibre and therefore butyrate, can compromise the health of the cells creating bigger gaps between them which allows contents of the gut that shouldn’t pass through, to do so. The racehorse is repeatedly exposed to new and different environments when travelling to different racecourses and encounters pathogens they might have no previous immunity to. Their reduced defensive barriers in the gut mean they are more vulnerable to these pathogens which can result in digestive upsets.  

So can more fibre be fed without compromising performance? 

Researchers at the Lab to Field research centre in Dijon, France believe so.  In work funded by the French government and published in Frontiers in Physiology, they found that Standardbred horses in training fed a third of their total ration as alfalfa with just 7% oats, performed comparably with those fed 33% oats (the remainder of the diet was hay). The horses were monitored over an 8 week period rather than just in a one-off standardised exercise test (SET). The replacement of a significant proportion of oats with alfalfa had no detrimental effects on performance or muscle tone and in fact, altered energy metabolism in such a way as to potentially improve performance and recovery the authors suggest (Martin et al., 2023). Studies back in the early 2000s (Nadeua et al, 2000; Lybbert et al, 2007) showed that alfalfa was more beneficial for horses with ulcers compared to grass forages because it helps counter the increased acidity that occurs when feeding cereals. This latest study suggests that alfalfa can actually replace a significant proportion of the cereals as an energy source too. 

The prevalence of gastric ulcers means it is an issue that needs to be addressed especially when viewed in the context of equine welfare in sport. Two recent studies have again shown how alfalfa has a key role to play in this regard too. The Lab to Field research group demonstrated that clinical success with horses with EGGD was 47.7 times more likely in horses fed alfalfa pellets as part of their ration compared to those on concentrate only rations (Julliand et al., 2023). 

In addition, a study published in 2024 showed that a combination of alfalfa, sugar beet and cereal fibre fed alongside the existing ration, aided the reduction in recurrence of gastric ulcers when fed during the healing and post-medication periods. This is key for when ulcer medication is stopped and the recognised rebound increase in acid production can occur (Menzies-Gow and Shurlock, 2024). 

A key point from these studies is that the quality of fibre matters. Alfalfa and sugar beet both contain higher proportions of digestible fibre such as pectin and hemi-cellulose, rather than indigestible fibrous elements such as lignin. This means they aren’t sitting in the gut for so long but they are being digested and utilised as an energy source. If fed in chopped forms they help to increase the amount of chewing the horse does and more chew time might actually be a relatively simple step in the right direction from a welfare perspective. The pros and cons of turning out racehorses have been widely debated but for those where it isn’t (currently) practical, it is surely a positive action to at least provide the horse with high fibre materials to eat when stabled, especially when it isn’t having a negative impact on their performance.

Dispelling Myths - Facts about Fibre

How much sugar does sugar beet contain?

The pulp fed to horses is actually really low in sugar – less than 5% assuming no molasses has been added back in. This is because the sugar has been extracted for use in the human food industry and the fibrous pulp is used for animal feed. 

Why does alfalfa contain more calcium than grass forages? 

Alfalfa has really deep roots – about 3 to 4 metres – and the calcium at this depth in the soil is more available for absorption. This means that alfalfa plants can take up more calcium than grass – chopped alfalfa contains between 30 - 50% more calcium than grass forages. Early studies suggest that omeprazole is reducing calcium absorption in the horse as is seen in humans and in Swanhall et al’s (2018) study, they recommend using bio-available calcium sources in the diet to help counteract this effect. Plant based sources of calcium such as alfalfa are much easier for the horse to absorb than inorganic sources such as limestone flour. 

Why is alfalfa so low in starch?

Like other plants alfalfa makes sugar when photosynthesising but it stores any surplus sugar as starch in its roots – the part that horses don’t eat! Grass plants tend to store sugar as fructan in leaves and the stem which is why they supply the horse with more sugar. 

What contribution can forage make to a racehorse’s requirements? 

Remember that grass-based forages contain sugar, both simple sugar (glucose, fructose etc) and as water soluble carbohydrates or storage sugars (fructan). 10kgs of hay can provide around 1kg of simple sugar and in the region of 2-2.5kgs of storage sugar. This supplies around 20% of the energy required by a 500kgs horse in intense training. Additionally, forage provides energy from the fibre it contains and so overall, including the contribution from sugar, 10kgs of hay would supply around 60-70% of the horse’s energy needs depending on the quality of the forage. 

Earlier cut forages tend to be more digestible and therefore supply more energy. These tend to be the wrapped forages in the UK and other wetter and colder European countries as there just aren’t long enough periods of dry weather to make good hay very often. Why is this significant? The way forages are conserved has changed over the years so now, a more accurate description of many forages previously defined as haylages, would be ‘wrapped hay’ as they are often very dry which has meant that little or no fermentation has occurred. This means the levels of acidity are no different to a normal hay which can be seen from the analysis results in table 1. Using lactic acid levels as a marker of acidity levels shows that most of the wrapped forages analysed in the UK are too dry for fermentation to occur and so the level of acidity is no different to hay. 

Concern about using a true haylage for horses with ulcers relates to the increased acidity from the fermentation that occurs. Clearly this doesn’t apply if the forage hasn’t fermented and so a wrapped hay may well be a really useful option for a horse with ulcers. They tend to be more palatable and softer than hay. It is important to know the level of acidity before making the decision to use a wrapped forage and having it analysed is therefore advisable. 

So if the paradigm shift happens, what will a racehorse’s diet look like in years to come? 

The basis would be a good early, cut wrapped hay. The daily bucket feed would consist of 1-2kgs of oats with 1.5kgs of alfalfa pellets, 1.5kgs of chopped alfalfa and 0.5kgs of soaked sugar beet. The chopped alfalfa  contributes to the horse’s overall forage requirement so if the dry matter of the wrapped hay is around 75%, a 500kgs horse would need a minimum of 8kgs per day to supply 6kgs of additional fibre on a dry matter basis. 

Key takeaways 

  • ESGD risk factors are well established and include too little fibre and too much starch 

  • Feeding at least 1.5% of bodyweight on a dry matter basis is the minimum amount of forage required for long term gastric and digestive health

  • Wrapped hays that have not fermented and so are no more acidic than hay are also appropriate to use for horses with ulcers

  • EGGD is still not fully understood but increasingly it is acknowledged by researchers that stress is a key contributing factor

  • Studies have shown alfalfa to be beneficial as an alternative energy source compared to cereals for horses in training

References 

Julliand et al (2023) Effect of diet composition on glandular gastric disease in horses. Journal of Veterinary Internal Medicine

Lybbert et al (2007), Proceedings of Annual Convention of the AAEP, Orlando, Florida, 2007. 

Martin et al (2023) Effect of high-starch or high-fibre diets on the energy metabolism and physical performance of horses during an 8-week training period. Front. Physiol. 14:1213032. doi: 10.3389/fphys.2023.1213032

Menzies-Gow and Shurlock (2024) The effect of feeding a commercial feedstuff on equine gastric squamous disease. Journal of Equine Veterinary Science. 133. 

Muller and Uden (2007) Preference of horses for grass conserved as hay, haylage or silage. Animal Feed Science and Technology, 132, (1-2) 66-78

Nadeau et al (2000) Evaluation of diet as a cause of gastric ulcers in horses. American Journal of Veterinary Research. Jul;61(7):784-90.

Pratt et al, (2022) Assessment of agreement using the equine glandular gastric disease grading system in 84 cases. Veterinary Medicine Science, 8 (4) 1472-1477doi: 10.1002/vms3.807

Swanhall et al (2018) Mineral and Vitamin Supplementation Including Marine Derived Calcium Increases Bone Density in Thoroughbreds. Proceedings of the Australasian Equine Science Symposium

Studying the feed behaviour of horses in training - why we keep on losing the battle with ulcers?

Article by Catherine Rudenko

Is this the biggest challenge when it comes to managing digestive health for horses in training? 

Keeping a racehorse healthy inside and out can be a real challenge. The nature of training and the environment in which racehorses live presents a constant set of risks. Managing those risks and balancing them against what is needed to achieve success is a fine art. 

So where does risk come from when it comes to digestive function? Are those risks manageable within the racing environment? What can you realistically expect to achieve with changes to feed, feeding practice and the use of supplements?

One of the biggest risk factors for digestive health is the stabled environment and the pattern of feeding required to fit in around a typical working day for stable staff, coupled with the need to get out on the gallops. On top of this is then the individual’s feeding behaviour, something that can easily be overlooked when the ‘what is fed’ is the same for all horses on the yard. Individual behaviour is perhaps one of the hardest aspects to tackle, whilst replicating a natural feeding pattern is nearly impossible.

The most common digestive concern is gastric ulcers, and many feeds and supplements are now available and marketed for this condition. Yet ulcers still exist and continue to frustrate many trainers despite making dietary changes. Why is this? The answer lies in gaining a better understanding of what a ‘good’ feed pattern and diet looks like from the horses’ perspective versus what is effective for performance and realistic in a typical racing yard. 

What is a natural feeding pattern?

Free ranging horses typically show 10-15 distinct feeding bouts in a 24-hour period (1).

Time spent resting or engaged in other non-feeding activities will not normally exceed 3-4 hours per session (2). Meaning the stomach is rarely truly empty.

The majority of feeding behaviour happens during daylight hours, typically 60-70% of time available (3).

During nighttime hours the amount of time spent as feeding behaviours reduces to 40-50% of those hours (3).

The total amount of time spent grazing across multiple feeding bouts is connected to the season and daylight hours. During summer months intake is around 14 hours in total versus 12 hours in the winter (4).

The natural feeding pattern is driven by the design of the horses’ digestive anatomy and is key to good health and normal function. The further away from these patterns we move any horse the greater the risk of dysfunction. 

What is a typical feeding pattern for a horse in training? 

The time study below shows the time taken for a group of 5 horses in training to eat their bucket feed and forage allocations in a 24-hour period. All horses in this observational study were in full training and worked in the morning of the study at different time points depending on their lot. Horses were observed from 4:45am until 9:15pm.  

One of the key aspects of natural feeding behaviour is the amount of feeding periods or ‘mini-meals’ a horse consumes. For 4 out of the 5 horses from completion of their evening forage to the next meal of breakfast was a period of time in excess of 8 hours , approximately 33% of the 24-hour period. During these nighttime hours feeding behaviour normally occurs in free ranging horses and supports regulation of the digestive system. 

For wild horses the total time spent eating is 12-14 hours in a 24 hour period. They do not normally have periods exceeding 12 hours in every 24 without some form of intake. For 4 out of the 5 horses there were distinct periods where all feed and forage had been consumed. The amount of time without any feed or forage available for the horses ranged from as little as 3 hours and 40 minutes up to 15 hours 30 mins in a 24-hour period.

Natural feeding patterns rarely see more than a 3-4 hour gap between each ‘mini-meal’ and at these points where gaps exist, it is important to remember that food has been available for 24 hours without restriction leading up to these chosen breaks in forage intake. The break in intake is short and during this time the stomach is unlikely to be truly empty. For horses in training it is easy to have periods in excess of 3 hours without any intake of feed or forage. 

Although the period from finishing breakfast to morning forage being given was for some horses less than 3 hours, the stomach when receiving that breakfast was in a fasting state. Ordinarily in the natural environment the stomach is rarely truly empty as it can take anywhere from 2-6 hours for the stomach to empty depending on what and how much has been consumed (5). When giving a bucket feed to a horse in a fasting state the rate of transit of that feed through the stomach will be relatively short, and depending on which lot the horse is pulled out for, can result in the horse being worked on an empty or near empty stomach. 

Why does this matter? 

One of the common causes of squamous ulceration is ‘acid splashback’ which relates to strenuous exercise and the movement of acidic content from the lower glandular region of the stomach to the unprotected squamous area (6). When the stomach contains feed or forage it is more difficult for the acidic content to be forced upwards to the squamous area. This is why it is recommended to include chaff in the breakfast feed or provide a small amount of forage as these fibrous sources are slower to pass through the stomach and can help reduce the level of acidity seen in the proximal portion of the stomach. The key point here is reduction not elimination. The practice will not prevent ulceration occurring, but it will reduce exposure.

The table below shows the difference between horses that were fasted for only 2 hours before exercise and those fasted for 18 hours. 

One of the challenges in racing is the differing amount of time between the breakfast feed and being saddled up for work. On top of this some horses will naturally consume their allocated feed faster. Even within the small number of horses observed in the study in Figure 1 there was notable variation in the time taken to eat the same amount of bucket feed given. Some of this variation comes from giving all horses the same breakfast by weight, which represents a different meal size against their bodyweight. Variation also exists as racehorses are individuals and appetite is flexible and influenced by other factors such as level of fitness and stress.  

Figure 3 shows the amount of dry matter provided in the breakfast feed to each horse and considers it against the bodyweight of the individual horse. The breakfast given was 2.2kg of a cubed racing feed alongside 0.6kg of an alfalfa based chaff. 

Can feed intake be slowed down?

In terms of feed format, pelleted feeds are consumed faster than mueslis or ‘sweet feeds’ (7). The addition of chaff mixed with the feed can slow intake, but for it to be effective there must be a reasonable amount given compared to the amount of pelleted or textured feed. As a rough guide, providing an additional 30% of the hard feed weight as a chaff will make a notable difference to the rate of intake. 

Whilst the aim is to slow intake it is important to keep in mind that feeding hard feeds too close to strenuous exercise is not recommended. Ideally feed is withheld for 2 hours before exercise. Forages, eg hay, haylage and alfalfa chaff, do not need to be removed but intake should be restricted to a small amount, typically 1kg. Providing a small amount of forage in this format helps maintain saliva production, which assists with regulation of acidity, and provides some fill for the stomach. 

Does forage intake matter?

Risk factors for gastric ulceration and colic when it comes to forage are similar. Diets low in forage and high in concentrates increase risk, along with intermittent feeding patterns and/or periods of fasting. 

In addition to what is given and the pattern that fits practically at a yard, is the fact that horses, like many other species, do not have a fixed rate of intake when a meal of any sort is presented. The majority will have a higher consumption rate at the start of feeding than at the end. With the observed horses hourly weigh backs of forage were carried out for a period of 6 hours to determine rate of consumption. During this time no bucket feed was present.  Figure 4 shows the individual intakes.

In the case of horses in training this is another problem to consider when it comes to evening feeds. Whilst the amount of forage given may be reasonable and in line with expected appetite, the feeding behaviour of the horse means there is not a consistent or regular intake of forage observed until the following morning feed.  True feeding of ad-lib forage, above what a horse needs or could eat in a 24-hour period, is rarely given and often impractical. The reality is that most horses in training will have a prolonged period of zero feed or forage intake during nighttime hours, which is the opposite of natural feeding behaviour. 

This is a practical challenge which for many yards is not easily overcome. Ideally forage should be fed at more regular intervals, rather than twice daily, to more closely replicate the 10-15 feeding bouts observed in wild horses. 

What can be done to improve feed patterns?

Simply put, the longer a horse spends eating the better. 

An enthusiastic eater that is ‘keen at the pot’ might be taken as a sign of good health, but a speedy intake that leads to a feeding pattern with longer periods between any sort of meal isn’t necessarily a good thing. A horse that appears a little slow with their forage but still consumes a good amount over a daily basis is not a bad thing as the pattern of eating is closer to multiple mini meals. 

  • Using a good amount of chaff in every feed will prolong feed intake and requires additional chewing which helps increase salivation. 

  • In the case of morning feeds ideally a little hay or haylage could be given, particularly for later lots to ensure the presence of some fibre in the stomach when working. Such a presence will not completely stop acidity in the delicate squamous area of the stomach, but it will reduce it. 

  • Providing the evening forage as late as is possible to reduce the amount of time between evening forage being consumed and breakfast given. 

  • Taking note of ‘speedy eaters’ and considering if hay nets or hay feeders would be appropriate to prolong the time taken to consume their evening allocation. Hay nets in different locations in the stable, for example one at the front and one at the back, can also influence how quickly all the forage is consumed. 

  • Consider the type of forage given. Hay can be easier to provide on more of a free choice basis as horses will consume less hay than haylage on a dry matter basis in a set period of time (1).

What is a realistic expectation for managing digestive health?

The need for high energy intakes to fuel performance means reliance on hard feeds and a limited amount of forage. The horse does not have an unlimited appetite and even when provided with additional forage will not necessarily consume enough or consume it in a regular fashion. Replicating a natural feed pattern for horses in training is close to impossible and inevitably results in digestive disorders, but making changes and trying to reduce that risk is worth doing. The differences made may be small, but winning margins can be just as small.

The purpose of feeding low starch diets to horses in training is to reduce the specific element of risk that comes from high starch feeding. In doing so that element of risk is managed and the diet is one step closer to a more natural fibre-based diet. But it is one area of risk alone and mitigating this risk does nothing to control the risk of ulcers or colic from intermittent feeding, the impact of withholding water,  the effect of travel and the physical effects on the stomach from strenuous exercise in the case of ulcers.

Using supplements that support healing of tissues, the function of mucus barriers or buffer acidity in the stomach are all part of trying to manage gastric ulcers, a disorder that is created through the training environment and the intensity of work required to achieve a race fit state. Such supplements are not designed to treat or prevent ulcers, they are not medicines and should not claim to do so, but they play an important part in trying to maintain a healthy digestive system.

Equally using supplements that support hindgut function through promoting the growth of beneficial bacteria, stabilising the pH of the hindgut or ‘mopping up’ pathogenic bacteria are all part of trying to maintain a healthy hindgut, which has many benefits, and reduces the risk of disorder within this section of the digestive anatomy. 

The most important thing when considering gastric ulcers and other digestive disorders is to be realistic about what you can achieve within your environment, and to be realistic about what difference feeds and supplements alone can make. Any steps that can be taken to reduce risk are worth implementing as the aim is to keep the digestive system as healthy as possible so that the food you provide is converted to the nutrients needed to maximise performance and maintain general good health.




References

1. Ellis,A.D.,2010. Biological basis of behaviour in relation to nutrition and feed intake in horses. In A.D. Ellis, A.C.Longland, M.Coenen & N.Miraglia, ed. The impact of nutrition on the health and welfare of horses. The Netherlands: Wageningen Academic Publishers, 53-74

2. Ralston,1984; Vulink,2001, cited in Ellis,A.D.,2010. Biological basis of behaviour in relation to nutrition and feed intake in horses. In A.D. Ellis, A.C.Longland, M.Coenen & N.Miraglia, ed. The impact of nutrition on the health and welfare of horses. The Netherlands: Wageningen Academic Publishers, 58.

3. Vulnik,2001; Boyd 1988; Berger et al.,1999; Edouard et al.,2009 cited in Ellis,A.D.,2010. Biological basis of behaviour in relation to nutrition and feed intake in horses. In A.D. Ellis, A.C.Longland, M.Coenen & N.Miraglia, ed. The impact of nutrition on the health and welfare of horses. The Netherlands: Wageningen Academic Publishers, 58.

4. Vulnik,2001 cited in ELLIS,A.D.,2010. Biological basis of behaviour in relation to nutrition and feed intake in horses. In A.D. Ellis, A.C.Longland, M.Coenen & N.Miraglia, ed. The impact of nutrition on the health and welfare of horses. The Netherlands: Wageningen Academic Publishers, 59.

5. Frape, D. (2010) Equine Nutrition and Feeding. 4th Edition. United Kingdom: Wiley-Blackwell

6. Lorenzo-Figueras,M. Merrit,AM. Effects of exercise on gastric volume and pH in the proximal portion of the stomach of horses. Am J Vet Res. 2002;63(11):1481-1487

7. Hintz et al 1985 cited in Geor,J. Harris,P. Coenen,M. (2013) Equine Applied and Clinincal Nutrition. China: Elsevier

Unravelling Ulceration

The causes, treatment and prevention for squamous vs. glandular gastric ulceration

Unravelling ulcerationthe causes, treatment and prevention for squamous vs. glandular gastric ulceration.Emma Hardy, PhDGastric ulcers remain a common condition facing competition horses. This poses an ongoing and persistent challenge to trainers wh…

By Emma Hardy, PhD

Gastric ulcers remain a common condition facing competition horses. This poses an ongoing and persistent challenge to trainers who face the negative effects of ulcers in terms of training and performance. To address the issue, the typical trainer spends a small fortune on scores of omeprazole and other ulcer remedies, only to find the problem isn’t resolved or simply comes back.

Meanwhile, researchers have been testing the very notion of “what is an ulcer?” The data casts doubt on whether go-to treatment approaches will actually work. A look at what the research now tells us about equine gastric ulcers may provide some new guidance for how best to address this nearly ubiquitous concern.

The two faces of gastric ulceration

While many people think of gastric ulcers as one specific disease, equine vets and researchers refer to gastric ulcers as a “syndrome” (Equine Gastric Ulcer Syndrome, or EGUS). The medical definition of a syndrome describes a set of symptoms and signs that together represent a disease process. In practical terms, this means that ulcers are really a clinical sign – truly a symptom – of underlying disease conditions.

A few years ago, articles began to appear in the scientific press highlighting differences in the healing of ulcers in two distinct regions of the stomach – the upper “squamous” area on the one hand, as compared to the lower “glandular” portion on the other. In recent years, researchers in Australia published a series of articles (Sykes et al, 2014) to “clarify the distinction between diseases in different regions of the stomach” – that is, to describe the differences between ulcers in the squamous area of the stomach from those in the lower glandular area. The articles described significant differences between the two conditions, including prevalence, risk factors and response to treatment.

Squamous gastric ulceration

The upper region of the stomach is minimally protected from the corrosive effects of stomach acids. As such, squamous gastric ulceration – that is, ulcers in the upper region of the stomach – is believed to result from the increased exposure to acid and other contents of the stomach. Ulcers in the squamous region are also more common, affecting upwards of 70% of thoroughbred racehorses, as demonstrated in multiple studies over the past 20 years.

Glandular gastric ulceration

By contrast, ulcers in the lower glandular region of the stomach are believed to arise from a different set of conditions. The lower portion of the stomach is composed of numerous cell types including those that secrete gastric acid. Because horses secrete stomach acid continuously, the mucosal lining in this lower portion of the stomach is in direct contact with stomach acid at all times.

Continuous fodder is just one way of preventing ulceration.

The lower portion of the stomach is also better protected – the glandular mucosa is lined with a thick layer of mucus that offers natural protection from acid. It is believed that glandular ulceration results from the breakdown of this protective lining. Although no research has conclusively shown exactly how this defence mechanism breaks down in horses, research in humans shows NSAID (non-steroidal anti-inflammatory drugs) use and bacterial agents are contributors.

Based on this, equine squamous gastric ulceration (ESGUS) is a specific condition distinct from equine glandular gastric ulceration (EGGUS).


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