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.
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
Feeding from the sales ring to racecourse
Author - Cath Dunnett
Horseracing’s international sales rings can perhaps be regarded or compared with the professional show circuit. To achieve optimum interest and price, youngsters not only need to be genetically well endowed but must be appealing to the buyers eye. Youngsters need to be in good body condition, ideally fit but not fat with good muscle tone, sufficient topline and a gleaming healthy coat. However the overall ‘picture’ desirable for the sales ring may not be the most appropriate for full training and competitive racing, and so trainers may find themselves needing to resculpture horses in their early days of training.
Yearling Prep
Yearlings are prepared (‘prepped’) intensively for the sales ring. Whilst most yearling prep regimes will incorporate some exercise, this tends to be mostly walking; and yearlings may lack the established and better developed musculature needed for racing. There is also a high reliance on feeding to deliver the ‘sales ring look’.
Prep regimes are often short lived and designed to increase weight and condition relatively quickly, and to produce gleaming coat condition and topline—the latter of which can therefore be based on deposition of adipose tissue or fat, rather than muscle development or hypertrophy.
A prep period typically involves feeding a large amount of high energy, starch-rich feed over a relatively short period of time, typically 6-8 weeks. Research tells us that this prep period is likely to be one of the high risk times for non-glandular gastric ulcers to develop. Large starch-rich feeds, confinement, increased periods of stress and restricted access to pasture or forage are all significant risk factors for gastric ulcers.
Some yearlings will inevitably arrive at the trainer or pre-trainers yard with pre-existing non glandular ulcers, which may require veterinary treatment, or at the very least a sympathetic high forage, low-starch and sugar-based ration for early training. It may be controversial to suggest, but a longer slower period of prep for sales would perhaps allow for a greater contribution from exercise to build muscle, combined with a less intense feeding regime. However, time and economics probably contain too much deviation from the existing model.
Bone Density
Yearlings that move through from studs to sales prep and then into a training yard undergo a very big change in their feed and management that is worthy of consideration. A stud regime and diet are very different to both sales prep and pre-training, in terms of composition and environment. At stud, these young animals spend a large portion of their day at pasture, with a generally small amount of top up feed or balancers to complement the grazing.
A diet, which is typically high in pasture and forage and low in cereals, allows minerals such as calcium to be firmly sequestered in bone, maintaining bone density. In horses on good pasture, this is aided by the high vitamin K1 content of pasture, which is needed to activate osteocalcin involved in the sequestration of calcium in bone. In contrast, with a high-cereal, low-forage prep or pre-training diet—as a result of quite complicated homeostatic mechanisms involving hormones such as parathyroid hormone—calcium can become relatively more mobilised from bone. The characteristic drop in bone density commonly seen in racehorses in the first 60-90 days of training can be the physical result of this phenomenon.
Forage First
Yearlings may come into training on the larger side of perfect for racing; and so it may, at first glance, seem counterintuitive to feed plenty of forage at this time. However, in early training it is a worthwhile exercise, as it establishes good eating habits.
Horses in training often self limit their forage intake, as training progresses and appetite is reduced, which can contribute to problems including inability to maintain condition, gastric ulcers and tying up if the forage intake drops too low. Better to start from a slightly higher intake early on, than to find a horse on a forage knife edge later in training.
Forage, whether hay or haylage, contributes significantly to energy and electrolyte intake and is a particularly rich source of potassium—an important electrolyte for overall metabolism and muscle function. Leguminous forage such as alfalfa/lucerne is highly digestible and so has a reduced effect on gut fill (hay belly). Alfalfa is equally rich in calcium to help buffer the natural mobilisation and loss of calcium from bone during early training.
A couple of kilograms of alfalfa per day complements a more traditional less digestible hay such as Timothy. The added advantage of feeding a decent amount of forage is that the level of concentrate feed needed will also be reduced. Forage provides energy mainly from fibre and so is not generally associated with excitability, with the energy provided being colloquially known as slow-release energy.
A decent amount of forage for a horse in training is about 1.5% of bodyweight; so for a 500kg horse, that’s about 7-8kg or 4 typical slices. For haylage, this needs to be slightly higher to account for its higher water content.
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Unravelling Ulceration
The causes, treatment and prevention for squamous vs. glandular gastric ulceration
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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Forage - So much more than just a filler
Too often thought of as just a filler or occupational therapy to while away the time between hard feeds, forage is worth so much more than that. Simply feeding an inadequate quantity of forage, or choosing forage that has an inappropriate nutrient profile, or is of poor quality can have a negative impact both on health and performance in racehorses.
Dr Catherine Dunnett (01 July 2007 - Issue Number: 4)
By Dr Catherine Dunnett
Too often thought of as just a ‘filler’, or occupational therapy to while away the time between hard feeds, forage is worth so much more than that. Simply feeding an inadequate quantity of forage, or choosing forage that has an inappropriate nutrient profile, or is of poor quality can have a negative impact both on health and performance in racehorses.
Inappropriate choice of forage and its feeding can easily lead trainers down the slippery slope towards loose droppings and loss of condition. Forage can also have a significant impact on the incidence and severity of both gastric ulcers and respiratory disease, including inflammatory airway disease (IAD) and recurrent airway obstruction (RAO).
When choosing forage the main elements to consider are
• Good palatability to ensure adequate intake
• Adequate digestibility to reduce gut fill
• Fitness to feed to maintain respiratory health
• A profile of nutrients to complement concentrate feeds
FORAGE CAN ONLY BE GOOD WHEN PALATABLE
Palatability is a key issue, as even the best forage from a quality and nutritional standpoint is rendered useless if the horses do not eat sufficient quantities on a daily basis. Palatability is a somewhat neglected area of equine research and so we largely have to draw on practical experience to tell us what our horses like and what they don’t. Some horses appear to prefer softer types of hay, whilst others prefer more coarse stemmy material. Many horses readily consume Haylage, whilst some trainers report that other horses prefer traditional hay. Apart from the physical characteristics, the sugar content of hay or haylage may affect its palatability. Forage made from high sugar yielding Ryegrass is likely to have a higher residual sugar content compared with that made from more fibrous and mature Timothy grass.
Some interesting research carried out a few years ago by Thorne et al (2005), provided some practical insight into how forage intake could be increased in the reluctant equine consumer. This work reported that the amount of time spent foraging (which will increase saliva production), was increased when multiple forms of forage were offered to horses at the same time. From a practical viewpoint this can be easily applied in a training yard and it should help to increase the amount of forage consumed. For example, good clean hay could be offered together with some haylage, and a suitable container of alfalfa based chaff or dried grass all at the same time.
A Healthy Intake
Racehorses in training often eat below what would be considered to be the bare minimum amount of forage to maintain gastrointestinal health. Whilst sometimes this is due to the amount of forage offered being restricted, in other instances it is because the horses are limiting their own intake. This may be due to either their being over faced with concentrate feed, or due to unpalatable forage being fed. Establishing a good daily intake of forage during the early stages of training and then maintaining the level through the season is important. Typically the absolute minimum amount of forage fed should be about 1% or 1.2-1.5% of bodyweight for hay or haylage, respectively. This equates to 11lb of hay or a rounded 15.5lbs of haylage for an average sized horse (1100lbs). The weight of haylage fed needs to be greater than that of hay due to the higher water content of the latter.
Intake of haylage needed to achieve a similar dry matter intake to 11lbs of hay
Moisture Dry Matter Weight of forage Percentage Increase above hay
Hay (Average) 15% 85% 11lbs
Haylage 1 30% 70% 13lbs 20%
Haylage 2 45% 55% 16.5lbs 50%
The dry matter of haylage needs to be consistent to allow a regular intake of fibre and reduce the likelihood of digestive disturbance or loose droppings. Ideally trainers should be aware of any significant change in dry matter, so that they can adjust the intake accordingly.
Forage intake is restricted in racehorses to firstly ensure that a horse consumes adequate concentrate feed to meet their energy needs and requirement for vitamins and minerals within the limit of their appetite. Secondly, the amount of forage fed is restricted in order to minimise ‘gut fill’ or weight of fibre and associated water in the hindgut, as this will restrict their speed on the racetrack.
BUT… inadequate amounts of forage in a horses’ diet has such a negative effect on health that the minimum amount fed must be kept above recognised ‘safe limits’. Choosing an early cut forage that is less mature and with more digestible fibre means that the ‘gut fill’ effect is lessened. In addition, horses can always be fed more forage during training with the daily quantity being reduced (within the safe limits) in the few days before racing where this is practical.
FITNESS TO FEED
Quality of forage, in terms of its mould, yeast and mycotoxin load, can have a major impact on respiratory health. A recent Australian report (Malikides and Hodgson 2003) highlighted the cost of inflammatory airway disease (IAD) in horses in training, in terms of loss of training time and of potential earnings, together with the associated cost of veterinary treatment. They estimated from their study group that in Australian racing up to 33% of horses in training can have lower airway inflammation, yet show no overt clinical signs.
Type and therefore quality of forage, as well as the quality of ventilation were singled out as the most significant risk factors in the development of IAD.
Forage is potentially a concentrated source of bacteria, mould spores and even harvest mites. Hay that has heated during storage, or that has been bailed with a high moisture content is likely to provide a greater load of these undesirable agents that can harbour substances that promote airway inflammation, such as endotoxin.
Purchasing good quality and clean forage from a respiratory perspective will certainly reduce the pressure placed on young racehorses’ respiratory systems. However, how does one achieve this?
• Microbiological Analysis – the price paid for a microbiological analysis of a prospective batch of hay is a worthwhile cost when the consequences of poor hay are considered.
Assuming the analysis is favourable, purchasing a larger batch for storage gives further peace of mind and spreads the cost further, providing of course that the storage conditions are appropriate.
Interpretation of the microbiology results as CFU/g (colony forming units/gram) for moulds, yeasts and Thermophillic actinomycetes is not difficult. As a rule of thumb the lower the CFU count the better. Whilst a very low mould or yeast count (<10-100) should not usually cause concern, more consideration of the merits of a batch of forage should be triggered by a CFU count that reaches 1000-10,000. Certainly if any Aspergillis species of mould are identified the alarm bells should be ringing. Aspergillis Fumagatus has particular association with respiratory disease including ‘Farmers Lung’ in humans.
Storage
A suitably sized storage area will allow storage of a good-sized batch of your chosen forage giving consistency through the season. It makes financial sense for the welfare of racehorses to make adequate provision for a good-sized storage area. Third party storage is also sometimes an option where this is not available on site.
Forage merchant or farmer?
A good working relationship with one or more farmers or forage merchants is essential to be able to consistently buy good hay. They need to know what you want to buy and you need to be able to rely on them to provide a high quality product through the season.
Forage merchant Robert Durrant stands by the principle that “A good forage merchant should be able to supply a trainer with the same high standard of hay for much if not all of the season”.
He adds that in his opinion “American hay English hay or haylage are all good options when they have been made well and the quality is high, but the quality of the American hays are consistently more reliable.”
NUTRITIONAL CONSIDERATIONS
The nutritional contribution made by forage should complement that made by the concentrate feed. Most racing rations are high in energy, high in protein and low in fibre. Therefore a suitable forage needs to be contrastingly high in digestible fibre with a limited level of energy and protein. However, where you have sourced early cut hay or haylage that is more digestible and higher in energy and protein, the concentrate feed intake should be adjusted to account for this. This will help to avoid the issue of over feeding of energy or protein. An excess of energy can result in undesired weight gain or over exuberance, whilst an excessive intake of protein at the very least increases the excretion of ammonia, which is a respiratory irritant. Whilst it is important to know the calcium and phosphorus content of forage, the trace mineral content is less significant as the concentrate feed will meet the majority of the horse’s requirement. The exception to this, however is where a batch of forage is identified as having a severe excess of one particular element, e.g. Iron which can reduce the absorption of copper.
Much emphasis is placed on finding an optimum concentrate feed and associated supplements, to enhance the diet of horses in training. The same emphasis should ideally be placed on a trainer’s choice of forage. Forage can so easily make or break the best thought out feeding plan.
Forage - so much more than just a filler
Too often thought of as just a ‘filler’, or occupational therapy to while away the time between hard feeds, forage is worth so much more than that. Simply feeding an inadequate quantity of forage, or choosing forage that has an inappropriate nutrient profile, or is of poor quality can have a negative impact both on health and performance in racehorses.
Dr Catherine Dunnett (European Trainer - Issue 18 - Summer 2007)
Too often thought of as just a ‘filler’, or occupational therapy to while away the time between hard feeds, forage is worth so much more than that. Simply feeding an inadequate quantity of forage, or choosing forage that has an inappropriate nutrient profile, or is of poor quality can have a negative impact both on health and performance in racehorses. Inappropriate choice of forage and its feeding can easily lead trainers down the slippery slope towards loose droppings and loss of condition.
Forage can also have a significant impact on the incidence and severity of both gastric ulcers and respiratory disease, including inflammatory airway disease (IAD) and recurrent airway obstruction (RAO).
When choosing forage the main elements to consider are
• Good palatability to ensure adequate intake • Adequate digestibility to reduce gut fill
• Fitness to feed to maintain respiratory health
• A profile of nutrients to complement concentrate feeds
FORAGE CAN ONLY BE GOOD WHEN PALATABLE
Palatability is a key issue, as even the best forage from a quality and nutritional standpoint is rendered useless if the horses do not eat sufficient quantities on a daily basis. Palatability is a somewhat neglected area of equine research and so we largely have to draw on practical experience to tell us what our horses like and what they don’t. Some horses appear to prefer softer types of hay, whilst others prefer more coarse stemmy material. Many horses readily consume Haylage, whilst some trainers report that other horses prefer traditional hay. Apart from the physical characteristics, the sugar content of hay or haylage may affect its palatability. Forage made from high sugar yielding Ryegrass is likely to have a higher residual sugar content compared with that made from more fibrous and mature Timothy grass. Some interesting research carried out a few years ago by Thorne et al (2005), provided some practical insight into how forage intake could be increased in the reluctant equine consumer.
This work reported that the amount of time spent foraging (which will increase saliva production), was increased when multiple forms of forage were offered to horses at the same time. From a practical viewpoint this can be easily applied in a training yard and it should help to increase the amount of forage consumed. For example, good clean hay could be offered together with some haylage, and a suitable container of alfalfa based chaff or dried grass all at the same time.
A Healthy Intake Racehorses in training often eat below what would be considered to be the bare minimum amount of forage to maintain gastrointestinal health. Whilst sometimes this is due to the amount of forage offered being restricted, in other instances it is because the horses are limiting their own intake. This may be due to either their being over faced with concentrate feed, or due to unpalatable forage being fed. Establishing a good daily intake of forage during the early stages of training and then maintaining the level through the season is important. Typically the absolute minimum amount of forage fed should be about 1% or 1.2-1.5% of bodyweight for hay or haylage, respectively.
This equates to 5kg of hay or a rounded 7kg of haylage for an average sized horse (500kg). The weight of haylage fed needs to be greater than that of hay due to the higher water content of the latter. Intake of haylage needed to achieve a similar dry matter intake to 5kg of hay Moisture Dry Matter Weight of forage % Increase above hay Hay (Average) 15% 85% 5kg Haylage 1 30% 70% 6kg 20% Haylage 2 45% 55% 7.5kg 50% The dry matter of haylage needs to be consistent to allow a regular intake of fibre and reduce the likelihood of digestive disturbance or loose droppings.
Ideally trainers should be aware of any significant change in dry matter, so that they can adjust the intake accordingly. Forage intake is restricted in racehorses to firstly ensure that a horse consumes adequate concentrate feed to meet their energy needs and requirement for vitamins and minerals within the limit of their appetite. Secondly, the amount of forage fed is restricted in order to minimise ‘gut fill’ or weight of fibre and associated water in the hindgut, as this will restrict their speed on the racetrack. BUT… inadequate amounts of forage in a horses’ diet has such a negative effect on health that the minimum amount fed must be kept above recognised ‘safe limits’.
Choosing an early cut forage that is less mature and with more digestible fibre means that the ‘gut fill’ effect is lessened. In addition, horses can always be fed more forage during training with the daily quantity being reduced (within the safe limits) in the few days before racing where this is practical.
FITNESS TO FEED
Quality of forage, in terms of its mould, yeast and mycotoxin load, can have a major impact on respiratory health. A recent Australian report (Malikides and Hodgson 2003) highlighted the cost of inflammatory airway disease (IAD) in horses in training, in terms of loss of training time and of potential earnings, together with the associated cost of veterinary treatment. They estimated from their study group that in Australian racing up to 33% of horses in training can have lower airway inflammation, yet show no overt clinical signs. Type and therefore quality of forage, as well as the quality of ventilation were singled out as the most significant risk factors in the development of IAD.
Forage is potentially a concentrated source of bacteria, mould spores and even harvest mites. Hay that has heated during storage, or that has been bailed with a high moisture content is likely to provide a greater load of these undesirable agents that can harbour substances that promote airway inflammation, such as endotoxin. Purchasing good quality and clean forage from a respiratory perspective will certainly reduce the pressure placed on young racehorses’ respiratory systems.
However, how does one achieve this?
• Microbiological Analysis – the price paid for a microbiological analysis of a prospective batch of hay is a worthwhile cost when the consequences of poor hay are considered.
Assuming the analysis is favourable, purchasing a larger batch for storage gives further peace of mind and spreads the cost further, providing of course that the storage conditions are appropriate. Interpretation of the microbiology results as CFU/g (colony forming units/gram) for moulds, yeasts and Thermophillic actinomycetes is not difficult. As a rule of thumb the lower the CFU count the better. Whilst a very low mould or yeast count (<10-100) should not usually cause concern, more consideration of the merits of a batch of forage should be triggered by a CFU count that reaches 1000-10,000. Certainly if any Aspergillis species of mould are identified the alarm bells should be ringing.
Aspergillis Fumagatus has particular association with respiratory disease including ‘Farmers Lung’ in humans.
• Storage –A suitably sized storage area will allow storage of a good-sized batch of your chosen forage giving consistency through the season. It makes financial sense for the welfare of racehorses to make adequate provision for a good-sized storage area. Third party storage is also sometimes an option where this is not available on site.
• Forage merchant or farmer - A good working relationship with one or more farmers or forage merchants is essential to be able to consistently buy good hay. They need to know what you want to buy and you need to be able to rely on them to provide a high quality product through the season. Newmarket based forage merchant Robert Durrant stands by the principle that “A good forage merchant should be able to supply a trainer with the same high standard of hay for much if not all of the season”. He adds that in his opinion “American hay English hay or haylage are all good options when they have been made well and the quality is high, but the quality of the American hays are consistently more reliable.”
PRO’S AND CON’S
Hay from colder climates e.g. UK, Ireland commonly used quality can be variable usually palatable economical Haylage. Usually clean dry matter can be variable Fermentation inhibits mould growth Need to feed more than hay Feed value often higher May need to adjust hard feed Usually palatable Beware of punctured bales Newmarket trainer James Eustace has used big bale haylage for many years he says “I found it increasingly difficult to reliably source good clean English hay. I am very happy with the haylage, as it is pretty consistent and it provides the dust free option that I wanted.”
Hay from warmer climates e.g. USA / Canada usually very clean May need to adjust hard feed Feed value often higher Premium price Usually palatable Newmarket trainer Ed Dunlop appreciates the advantages of using more than one forage source he says, "American hay gives us the consistent good quality that we need and the horses eat it well. Feeding it alongside other forage gives us the flexibility needed for different horses throughout the season." Alfalfa (High temperature dried or sun dried)
Good adjunct to forage (e.g 1-2kg) High intakes can oversupply protein and calcium Can be used as chaff Leaf fragments can add to dust High feed value & digestibility Less gut fill Many of Forage merchant Robert Durrants clients choose sun dried alfalfa as an extra treat for the horses he says “the horses get a large double handful daily as a treat and they love it.”
NUTRITIONAL CONSIDERATIONS
The nutritional contribution made by forage should complement that made by the concentrate feed. Most racing rations are high in energy, high in protein and low in fibre. Therefore a suitable forage needs to be contrastingly high in digestible fibre with a limited level of energy and protein. However, where you have sourced early cut hay or haylage that is more digestible and higher in energy and protein, the concentrate feed intake should be adjusted to account for this. This will help to avoid the issue of over feeding of energy or protein. An excess of energy can result in undesired weight gain or over exuberance, whilst an excessive intake of protein at the very least increases the excretion of ammonia, which is a respiratory irritant.
Whilst it is important to know the calcium and phosphorus content of forage, the trace mineral content is less significant as the concentrate feed will meet the majority of the horse’s requirement. The exception to this, however is where a batch of forage is identified as having a severe excess of one particular element, e.g. Iron which can reduce the absorption of copper. Much emphasis is placed on finding an optimum concentrate feed and associated supplements, to enhance the diet of horses in training. The same emphasis should ideally be placed on a trainer’s choice of forage. Forage can so easily make or break the best thought out feeding plan.