Why the fibre you feed matters
It’s not only what’s in a feed that’s important, where it comes from matters too.
A great source of calcium
Alfalfa is an effective buffer to acidity in the gut due to its abundance in calcium and studies have shown it buffers acidity more effectively than grass-based forages. Just half a scoop of pure alfalfa chopped fibre in each feed will help counteract the acidity produced by feeding cereals.
A study has shown that omeprazole can negatively impact calcium absorption – this has already been shown in humans. Whether this is contributing to an increased risk of bone fractures is yet to be confirmed but it is certainly worth providing additional calcium in the ration as a risk reduction strategy. The calcium in alfalfa is highly bioavailable and so easier for the horse to absorb. Just 1 scoop of Dengie Alfa-A Original provides a 500kgs exercising horse with 1/5th of their daily calcium requirement*.
Proton Pump Inhibitors (PPIs) such as omeprazole have also been shown to significantly impact the bacterial populations in the digestive tract of humans making them more prone to digestive upsets and infections. This hasn’t been explored in the horse to date but if the same effect is seen it reiterates the importance of doing everything else possible to promote good gut health.
Consistently Clean
When the difference between winning and losing is marginal, doing everything you can to maximise respiratory health and function makes sense. Precision drying is a way of conserving forages that ensures they are as clean as possible and helps to lock-in nutrients as well. Every bag of Dengie fibre is dried by us and we can trace each one back to the field it was grown in.
Many people don’t realise that some so-called performance feeds contain straw. At Dengie we believe straw is a useful ingredient but not for the performance horse! It’s simply a case of using the right fibre for the right horse. Our feeds are regularly tested for mould with levels routinely below 100 CFUs and often below 10CFUS. To put that in context, sun-dried forages such as hay and straw often contain 1000CFUS or more.
Tempting the fussy racehorse
Findings from our Senior Nutritionist’s PhD research suggests that hospitalised Thoroughbreds are more likely to go off their feed than other breeds even when gastric ulcers have been ruled out. Interestingly, previous studies have also found that Thoroughbreds experience a higher rate of post-anaesthetic gastrointestinal complications such as colic, reduced faecal output and colitis compared to non-Thoroughbred horses. Dengie Performance Fibre has been developed to try to tempt even the fussiest horse and has proven to be particularly successful.
*Based on NRC guidance for a 500kgs horse in exercise and a calcium level of 1.5% in alfalfa
For further information please visit www.dengie.com or call +44 (0)1621 841188
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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 (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.
Time for a re-think? Why do we deny a horse water and fibre before a race?
Removal of fibre and water intake before a race are supposed to enhance performance in Racehorses… Surely this is not sound practice, let alone science. No sensible, modern day athlete would go out of their way to cause discomfort in their digestive system and thereby reduce performance, let alone remove hydration.
Removal of fibre and water intake before a race are supposed to enhance performance in Race Horses… Surely this is not sound practice, let alone science. No sensible, modern day athlete would go out of their way to cause discomfort in their digestive system and thereby reduce performance, let alone remove hydration. Perhaps the racing industry should look outside their field of view and take a leaf out of the endurance horse world. In this field of horsemanship, horses are fed just before and even during competition and hydration of the horse is paramount. Common sense says that a happy and comfortable horse will give us its ‘all’. Perhaps now is the time for a bold trainer to take this on board. The following is a more scientific rational behind my thinking.
The evolution of the horse into the animal we know today has meant the development of a very specialised digestive system. The proportionally huge hind-gut indicates the importance of fibre/forage in the equine diet. The specialised stomach has evolved to cope with a nearly continuous intake of fibrous plant material, so that (unlike the stomachs of omnivorous and carnivorous animals) the pyloric sphincter allows a ‘trickle’ of partly digested material into the small intestine. This function may cause a problem for horses fed a high level of concentrates as this ‘trickle’ mechanism can allow food to pass through the sphincter, before sufficient digestive processes have taken place. Also the acid level in the equine stomach is relatively high, as it has evolved to start the breakdown of cellulose in plant material, ready for digestion.
It has been suggested that inadequate provision of fibre in the diet may be a reason for many cases of stomach ulcers in horses. For optimum health and performance all horses require a balanced supply of :- Fibre – 1) indigestible fibre – for gut health and motility and 2) digestible fibre for nutrients and energy – the cellulose of plant material is broken down by colonies of microbes in the hind-gut into ‘complex’ carbohydrates, producing Volatile Fatty Acids which are absorbed into the blood stream, transported to the liver and converted into fat. This fat can be utilised by the body cells for energy or stored as adipose tissue until further energy is required. The process of fermentation and absorption of volatile fatty acids continues for many hours, so that horses may draw on the stored energy as required.
Good quality hay and pasture can provide much of the essential nourishment required for general maintenance and health, always providing that a balanced supply of micronutrients is fed. For horses in strenuous work, high energy fibre sources such as alfalfa chaff and sugar beet shreds can be a valuable part of the ‘short’ feed. The provision of adequate dietary fibre, in the daily diet, satisfies the equine ‘trickle’ feeding system and also the physiological and psychological need to chew.
Starch & Sugars – ‘simple’ carbohydrates for an energy supply – from oats and micronised cereals, Care has to be taken with quantities fed, as cereal overloading has been considered as a possible ‘trigger’ for problems such as ‘set-fast’, laminitis, azoturia etc. The choice and balance of cereals in the diet is also important, as some horses have been found to show an apparent intolerance to barley, exhibiting skin eruptions, filled legs and/or excitable ‘mood swings’. Cereals are broken down into their component glucose molecules in the small intestine and absorbed into the blood stream.
This ‘blood sugar’ can be directly utilised by the muscles as a valuable ‘fast release’ energy source for short bursts of strenuous work or stored in the muscles or the liver as glycogen. During prolonged exercise a problem found to be associated with fatigue – hypoglycaemia (low blood sugar) – may be avoided by the provision of sugars such as molasses in the diet. Vegetable Protein – for tissue repair and development of almost all body constituents; Cereals contain a very small percentage of protein which is digested in the small intestine. Soya beans, an excellent source of quality protein, are also digested in the small intestine; providing the 22 amino acids commonly recognised as essential in the horse’s diet. Most importantly the limiting amino acids lysine and methionine, as they are likely to cause metabolic problems if in short supply. Methionine is classified as an essential amino acid, it helps lower cholesterol levels, reduces liver fat protects the kidneys and regulates ammonia formation, also a natural chelating agent for heavy metals.
Certain amino acids are necessary for the metabolism and utilisation of energy. It is recommended that care should be taken to supply a correct balance of protein for horses under six years of age, as they are still in the growth and body building stage and will have greater requirements for protein and the associated, necessary micronutrients than the mature horse. Lysine is the amino acid involved with growth as are the minerals calcium, phosphorus, copper and zinc for the strength and integrity of cartilage and bone. However overly high intakes of protein can lead to an increase of urinary ammonia producing and/or aggravating respiratory problems for the stabled horse. Also, over feeding protein can cause an increase in the requirement for water possibly leading to a certain amount of dehydration and at least very wet beds - with a resulting increase of ammonia! . Fats/Oils – 1) as an energy source, 2 ¼ times the energy of carbohydrates per unit weight. 2) as an insulating layer of subcutaneous fat and 3) for development and maintenance of cell membranes. It is thought that fats may prove valuable in increasing the performance of horses at sustained submaximal exercise by providing a higher energy density diet, with the risks of carbohydrate overloading likely to be reduced.
The horse conditioned to an intake of oil in the diet will be able to accept more demanding training sessions, leading to increased fitness and performance . Made up from ‘chains’ of fatty acids, linoleic, linolenic and arachidonic acids are considered to be important for the horse.
If the blood glucose and muscle and liver glycogen energy stores have been depleted then the body will convert to fat oxidation for metabolic energy. – from ‘ The Scientific Rational for High Fat Diets for Equines’ Deborah M Lucas MSc, CBiol, MIBiol, R.Nutr. Minerals – almost every body process requires a correct supply (the feral horse fulfilled requirements from a variety of herbage grown in different soil types).
Minerals rarely act on their own, but interact in groups and with Vitamins, so that a deficiency or excess of one may affect many body processes; for example, research suggests that excessive iron intake may cause a type of metabolic corrosion affecting both respiratory tissue and working muscle. Also a balanced supply of trace elements such as selenium, copper, zinc and manganese along with vitamins E and C is advisable, to protect cell membranes from ‘free radicles’ and help control ‘oxidative’ stress for horses in heavy exercise, under stress and when travelling etc. Vitamins – as above almost every body process requires a correct supply.
Vitamins rarely act in isolation but interact with other vitamins and with minerals. For optimum health and performance a correct and balanced supply is essential. For example – the normal requirement for Vitamin K (important for the blood clotting mechanism) can be met through microbial digestion in the gut, if quality forage is supplied; but a deficiency has been considered to be a cause of pulmonary bleeding and internal haemorrhage, so it should be supplied in the diet of the stabled, working horse. The important B complex vitamins can also be manufactured by the gut microbes during the digestion of forage, but additional dietary supplementation will be required for stabled horses in work . The correct storage of Vitamins is vital as they are sensitive to heat, light, moulds and oxidising agents.