The Importance of Feeding Hay to Your Horse

Hay, and forage more broadly, is the single most important part of your horse's diet. Get the hay right and you support almost everything else: a settled gut, healthy teeth, a calmer mind, and a lower risk of some of the most common equine health problems. The hard feed, supplements and treats all sit on top of that fibre foundation, not in place of it.

A quick, honest note first. Huds and Toke makes Australian-made horse treats, and we are an Australian family business, not a veterinary practice. This is general educational information, with every health claim drawn from named authorities and cited below. For anything specific to your horse, especially sudden weight loss, suspected colic, laminitis or dental pain, please speak to your Australian equine vet first.

Why is hay so important for horses?

Hay is so important because a horse's entire digestive system evolved to process a near-constant trickle of fibre, not big meals of grain. Forage is the fibrous plant material, such as hay and pasture, that forms the foundation of a horse's diet, and everything else depends on it. A wild horse does not stand at a feed bin twice a day; it wanders, grazes, walks and grazes again, almost around the clock. Across the science of equine nutrition and the role of forage, the same theme keeps coming up: the horse is a trickle feeder, and the gut is built to work continually.

How the digestive system is built for forage

The horse's digestive tract is essentially a long fibre-fermentation machine. According to RSPCA Australia, "horses have evolved to eat a very high fibre diet so this should be the main component of any feeding regime," their "gut is designed to work continually," and they are "meant to graze and browse for at least twelve hours a day."

Two parts of the system make this clear. As Professor Paul McGreevy of the University of Sydney explains, "The stomach of an adult horse is relatively small (nine to 15 litres) and inelastic, so it empties within about 20 minutes." That is a gut built for a steady stream of small mouthfuls. Most of the real digestive work then happens in the hindgut, where billions of microbes ferment fibre into the energy your horse runs on. This process, known as hindgut fermentation, only works well with a steady flow of forage. Starve it of fibre and you starve the microbes that keep your horse healthy.

What happens without enough forage

When a horse goes without enough forage, problems start at both ends. Chewing itself matters: as McGreevy notes, "Saliva is a natural buffer to excess gastric acidity, but in horses, its production depends on pressure on the parotid salivary gland during chewing," so less chewing means less of that buffer. Lower down, an empty hindgut means stressed microbes and a gut that is not moving as it should. Biosecurity Tasmania is blunt: "Gut and behavioural problems may develop if a horse does not have access to some roughage throughout the day if all its nutrition is supplied in 1 or 2 meals." The empty hay net is not a neutral state. It is a low-grade stress on the whole system.

How much hay should you feed a horse per day?

As a starting point, feed your horse around 1.5 to 2.5% of its bodyweight in dry matter each day, most of it from forage. For a typical 500 kg horse, that is roughly 7.5 to 12.5 kg of hay daily. This is a guide, not a fixed rule, and the right number depends on your horse's workload, age, body condition and how much pasture it already gets.

Biosecurity Tasmania sets out the range clearly: "Mature horses will need between 1.5% and 2.5% of their bodyweight in dry matter per day. Growing horses may need up to 3%." Agriculture Victoria offers a handy rule of thumb: "Horses are able to consume about 1.5 to 2% of their body weight in dry feed each day. As a rule of thumb, allow 1.5 to 2 kg of feed per 100 kg of the horse's body weight."

Working it out by bodyweight

The simplest method is to start from your horse's weight. For every 100 kg of bodyweight, allow about 1.5 to 2 kg of feed per day. A 500 kg horse lands around 7.5 to 10 kg as a baseline, scaling up toward 12.5 kg for horses that need more.

One practical note: these percentages are dry matter, the feed once you take the water out. Hay is roughly 85 to 90% dry matter, close to its as-fed weight, while fresh pasture can be 70 to 80% water, so a horse must eat far more grass for the same dry matter.

Adjusting for workload, age and condition

The headline number is a baseline, and real horses need adjustment. A horse in hard work may need more forage plus some hard feed, while a retired pony on good grass may need far less, even restricted to manage weight. The honest test is body condition over weeks, not a single chart: ribs you can feel but not see, with a smooth topline, is the rough target, though your vet can score it properly for your individual horse.

Whatever the workload, the forage-first principle holds. Agriculture Victoria advises that "concentrates such as grains should make up a maximum of 30% of a horse's diet, and should be introduced gradually," and that you should "ensure that at least 70% of the feed is roughage." It also recommends you "feed twice a day," noting "small frequent feeds are better than a once daily feed." More meals, smaller portions, more forage: that is the pattern the gut wants.

How pasture changes the amount

Pasture is forage too, and it counts toward the total. A horse on good spring pasture may not need much hay at all, while the same horse in a bare summer paddock or a stable needs the whole forage ration made up with hay. The skill is watching the grass and the horse, and topping up so the gut always has fibre to work on. Sudden swings, such as moving onto rich pasture overnight, can trigger trouble, which is why gradual is the watchword throughout this guide. That is also why a horse on lush pasture may barely touch its hay, while one on a dry winter paddock empties the net.

Can a horse live on hay alone?

Many healthy adult horses at rest can live well on good quality hay, plus fresh water and a salt or mineral source. Hay is the natural base of the diet, and for an easy keeper in light work it may be most of what is needed. The catch is that hay rarely supplies everything, so most horses benefit from filling a few specific gaps.

What hay does and does not provide

Hay gives a horse fibre, a good deal of its energy, some protein, and a slow, satisfying way to spend the day eating. What it often falls short on is a balanced supply of certain vitamins and minerals, and levels vary with soil, season and storage. Vitamin E drops as fresh grass is cut and cured into hay, many Australian soils are low in particular trace minerals, and salt is almost always worth adding, since hay is low in sodium and horses lose it in sweat.

When a ration balancer or hard feed is needed

This is where a ration balancer earns its place. It is a low-volume feed designed to top up the vitamins, minerals and quality protein that forage misses, without adding much energy or sugar. For a horse that holds condition well on hay, a balancer often does the whole job. Horses that need more, those in hard work, growing youngsters, pregnant or lactating mares, hard keepers, or any horse that is unwell, usually need additional feed on top of forage.

What type of hay is best for horses in Australia?

There is no single best hay, because the right choice depends on the horse in front of you. In Australia, grassy hays such as Rhodes grass, meadow and pasture hay form the everyday base for most horses, oaten and cereal hay suit horses in work, and lucerne is the protein-rich option for horses that need condition. The art is matching the type, and the proportion, to your horse's needs, and understanding the basics of hay as a feed makes that easier.

Grassy hays

Grassy hays are the bread and butter of Australian horse feeding. Rhodes grass, meadow, pasture and teff hays tend to offer moderate protein, around 8 to 12%, and are generally lower in sugar and starch than cereal hays. That makes them a sensible everyday base for most horses, and a particularly good fit for ponies and easy keepers. Rhodes grass, a warm-season tropical grass, often sits under about 12% non-structural carbohydrate, which is part of why it is so commonly recommended for horses watching their sugar intake.

Oaten and cereal hay

Oaten hay and other cereal hays are palatable and higher in energy, which makes them popular with horses in solid work. The trade-off is sugar and starch. Cereal hays tend to be higher in both than grassy hays, which makes them a poorer choice for laminitis-prone or overweight horses. For a fit horse in work with no metabolic concerns, oaten hay can be useful. For an easy keeper or a pony, it is usually the wrong tool.

Lucerne (alfalfa)

Lucerne, also called alfalfa, is a legume hay rather than a grass, and it sits in a category of its own. It is high in protein, commonly around 16 to 20% or more, and high in calcium, which makes it valuable for growing horses, lactating mares and hard keepers needing extra condition. The flip side is that lucerne is easy to overfeed. Its protein can far exceed an adult horse's needs, and its calcium-to-phosphorus ratio can exceed 4 to 1, while the ideal whole-diet target sits nearer 2 to 1.

For that reason, lucerne is usually best fed as a portion of the forage, not the whole ration. A common approach is for lucerne to make up roughly 20 to 30% of the forage, with grassy hay making up the rest. As independent Australian equine nutritionist Dr Carol Layton of Balanced Equine puts it, "It would be unwise to only feed Lucerne (also known as Alfalfa) as the majority forage, not just because protein would far exceed needs." She also warns that too much lucerne calcium can lead to "precipitation of calcium in the urine which could cause sediment or even stone formation." As part of the mix, lucerne is a great tool. As the whole diet, it can cause problems.

Judging hay quality

Whatever the type, quality matters as much as the label on the bale. Good hay has a sweet smell, a greenish colour and a soft, leafy texture, and it is free of dust, mould, weeds and foreign material. Run your hand into the bale and check for warmth or damp, which can signal mould. The most reliable way to know what is actually in your hay, especially its sugar level, is a hay analysis, a simple lab test that takes out the guesswork. For most horses a visual and smell check is enough, but for at-risk horses a lab test is worth every cent.

Figures are approximate and vary by batch, season and soil. A hay analysis is the only way to know a particular hay's true protein, mineral and sugar content. When in doubt, involve your vet or an equine nutritionist.

How hay protects your horse's health

Feeding plenty of good hay is one of the most powerful, lowest-tech things you can do for your horse's health. A steady forage supply is associated with a lower risk of gastric ulcers and colic, supports natural dental wear, helps manage sugar intake for metabolic horses, and keeps the gut moving as it was built to. None of this is a guarantee or a replacement for veterinary care, but the evidence that forage matters is strong and consistent.

Gut health and gastric ulcers (EGUS)

The clearest link is with gastric ulcers. Equine gastric ulcer syndrome (EGUS) is common, and an empty stomach is a big part of the story. As Murray Veterinary Services, an Australian equine practice, explains, the horse's stomach produces acid around the clock, roughly 30 litres a day, whether or not it is eating. "When empty, the stomach is exposed to high concentrations of acid, buffered only by the bicarbonate in saliva." Keep forage flowing and you keep that acid buffered; let the stomach sit empty and the acid has nothing to work against. International peer-reviewed research adds that horses normally chew for 16 to 20 hours a day, producing the saliva whose bicarbonate is that natural buffer (Acta Veterinaria Scandinavica, overseas journal).

The prevalence figures are sobering. Murray Veterinary Services reports that recent studies found gastric ulcers in around 95% of racehorses, 93% of endurance horses, 63% of performance horses and nearly 50% of foals. Leisure horses fare better at around 37%, but no group is immune. The pattern is consistent: the harder the work and the more restricted the forage, the higher the ulcer risk.

Source: Murray Veterinary Services, "Equine Gastric Ulcer Syndrome (EGUS)" (Australia).

The RSPCA backs the management message: "Access to pasture, fibrous feed, and opportunities to feed frequently are considered to reduce the risk of stomach ulcers in horses." The ECEIM consensus statement (Sykes and colleagues, 2015, an overseas veterinary consensus document) agrees, identifying intermittent feed deprivation as a recognised risk factor for squamous gastric disease and noting prevalence can rise toward 80 to 100% within two to three months of intensive race training. Forage is not a cure, but near-constant access to it is one of the most effective things owners can do to reduce the risk.

Reducing colic risk

Colic has many causes, but feeding management is one of the biggest levers you control. A gut kept moving by a steady supply of fibre is at lower risk of the impactions and disturbances that lead to colic. The risk rises sharply with sudden change, whether a new batch of hay overnight, a swing onto rich pasture, or long gaps with no forage. Keep fibre flowing, make changes gradually, and always have clean water available, since dehydration is itself a colic risk. Any horse showing colic signs, such as pawing, rolling, looking at its flank or going off feed, is a same-day call to your Australian equine vet.

Laminitis and managing sugar (NSC)

For horses prone to laminitis, hay choice is not a detail, it is central, because equine metabolic syndrome and insulin problems sit behind many cases. As the University of Queensland Veterinary Medical Centre (UQ VETS) states plainly, "Equine metabolic syndrome (EMS) is the most common cause of laminitis," and its feeding guidance is specific: "As a general rule, we recommend feeding 1.5% of body weight in roughage that is low in non-structural carbohydrates (under 10% NSC content)."

The sugar content of hay is not fixed. AgriFutures Australia, in government-published research on managing pasture to reduce laminitis risk, notes "environmental conditions can trigger three-fold increases in NSC in pasture plants and hay," and that "native Australian grasses are lower in NSC than introduced, exotic species when grown under the same conditions." AgriFutures also underlines the stakes: "Laminitis is a leading cause of death in horses and makes a significant financial and emotional impact on the horse industry." As general guidance, at-risk horses are commonly fed forage under about 10 to 12% NSC, at roughly 1.5% of bodyweight. Grassy and tropical hays such as Rhodes grass are often, though not always, lower in NSC, while oaten hay tends to be higher. A lab analysis is the only way to know a hay's true sugar level, and a laminitis-prone horse should always be managed alongside your vet.

The same low-sugar thinking applies to rewards. Our guide to low-sugar, vet-informed treats for laminitis-prone horses shows how to keep the occasional reward in step with a carefully managed diet. The forage stays the foundation, and treats stay small and sensible on top.

Dental health and natural chewing

Chewing hay is dental maintenance your horse does for itself. Vet Voice, the public information service of the Australian Veterinary Association, explains that "horses' teeth continue to grow throughout the horse's life to compensate for the high degree of wear of abrasive fibrous food material." That long, grinding, side-to-side chew on coarse forage is exactly what those continuously erupting teeth evolved to meet. Take the fibre away and you change the wear pattern.

When wear gets uneven, sharp enamel points can form on the molars, and Vet Voice notes these "can lead to ulceration in the cheeks and tongue." That is painful and can put a horse off its feed. Good forage supports natural wear but does not replace routine dental checks. Most horses benefit from a dental examination by a vet or qualified equine dentist at least once a year, and any horse that drops feed, quids (drops balls of half-chewed hay), or holds its head oddly while eating should be checked.

Respiratory health and dust

The quality of your hay matters for your horse's lungs as well as its gut. Dusty or mouldy hay is associated with lower-airway inflammation and equine asthma, the condition formerly known as heaves or recurrent airway obstruction, because the dust and mould spores are exactly what sensitive airways react to. Soaking or steaming hay reduces respirable dust and is a common management step for airway-sensitive horses. This is general guidance, not a cure, and any coughing, nasal discharge or laboured breathing is a reason to call your vet.

Hay, behaviour and welfare

A horse with constant forage is usually a calmer, more settled horse, and that is not a coincidence. Grazing is what horses are built to spend their day doing, and taking it away leaves a gap that often shows up as stress and unwanted habits. Feeding plenty of hay, ideally close to constantly, is one of the kindest things you can do for a horse's mind as well as its gut.

The numbers make the point. The RSPCA notes that "in the wild, horses will spend approximately 60% of their time eating," while "stabled horses fed a restricted fibre diet may spend as little as 15% of their time feeding." That is a huge drop in the activity a horse most wants to do, and stabled horses on restricted fibre "may perform more unwanted behaviours such as chewing on stable fixtures, rocking from side to side (known as weaving), or pacing."

These repetitive habits, including weaving, pacing and cribbing, are called stereotypies. McGreevy reports that "approximately 10% of racing thoroughbreds showed the equine equivalent of obsessive compulsive disorders, called stereotypies." Once established, stereotypies are very hard to undo, which is why prevention through ad-lib forage and a natural routine matters so much. A horse that can chew for most of the day has far less reason to chew the stable door.

This is where the relationship side of horse keeping comes in. Calm quiet time with your horse, plenty of forage, turnout and company all build a settled animal. When you do reward, you are rewarding the calm, the patience at the hay net, the good paddock manners. The treat is a bonding tool, not a feed. The wellbeing comes from the relationship and routine.

Practical hay feeding tips

Good hay feeding is mostly about extending eating time, keeping hay clean, and changing things slowly. The goal: keep fibre in front of your horse for as much of the day as you safely can, in a form that is clean, palatable and matched to its needs. Here are the practical levers that make the biggest difference.

Slow feeders and hay nets to extend forage time

Slow feeders and small-hole hay nets are the easiest way to stretch a forage ration across more hours. By making your horse work for each mouthful, they turn a pile of hay that would be gone in an hour into a steady trickle that mimics natural grazing, keeps the gut buffered for longer, and reduces boredom. For easy keepers whose hay is restricted for weight control, a slow feeder is especially valuable, because it rations the amount without long, stressful gaps. Hang nets safely so a shod hoof cannot get caught, and check holes are large enough that your horse does not become frustrated.

Should you soak or steam hay?

Soaking and steaming both have their place. Soaking for around 30 to 60 minutes lowers water-soluble sugars and dust, which suits laminitis-prone and respiratory-sensitive horses, though it washes out some nutrients, so do not over-soak and feed it promptly. Steaming, using purpose-built equipment, kills mould and reduces respirable dust while keeping more nutrients, making it a good choice mainly for airway health. Neither is necessary for every horse. Plain, clean, good-quality hay is fine for most. Save soaking and steaming for the horses that genuinely need them, and plan the approach with your vet.

How to transition between hays safely

Change hay gradually, mixing in increasing amounts of the new hay with the old. Agriculture Victoria advises changing feed over at least 3 to 5 days, since "a sudden change in diet can cause colic or laminitis." Many owners take longer, around 7 to 14 days, when switching to a completely new type of hay, which is a sensible, cautious extension rather than a strict requirement. The reason for going slow is the hindgut microbes that ferment your horse's fibre. They adapt to a particular forage, and a sudden switch disrupts that population, which is associated with an increased risk of colic and loose droppings. A slow blend gives them time to adjust.

1. Start (minimum 3 to 5 days): begin with about three-quarters old hay, one-quarter new, then build up the new hay each day.
2. Roughly the midpoint: aim for about half and half.
3. Toward the end: shift to about one-quarter old, three-quarters new.
4. For a completely new forage (up to 7 to 14 days): stretch the change out further before going fully onto the new hay.
5. Throughout: watch appetite and manure, and slow the change if anything looks off. When in doubt, ask your vet.

Hay and water

Fresh, clean water comes first, always. Fibre needs water to move through the gut, and a horse eating dry hay without enough water is at real risk of impaction colic. Agriculture Victoria advises that you "provide fresh, clean water at all times," noting "ponies may require 15 litres per day and horses 30 litres per day," and that "these requirements can double in hot weather or when the horse is being exercised." Queensland's Department of Primary Industries puts the everyday range a little wider, noting "a horse will drink between 25 to 50 litres of water a day depending on temperature and the moisture content of the feed," and warns that "if horses become dehydrated, they are more susceptible to developing colic." Keep troughs and buckets clean, topped up and not fouled. In hot Australian summers a horse can drink huge volumes, while in winter horses sometimes drink less than they should, so watch intake year-round.

Storing hay to keep it clean and mould-free

Store hay off the ground, under cover and with airflow so it stays dry and mould-free, since mouldy hay is bad for both gut and lungs. Keep bales on pallets or a raised floor, away from rain and roof leaks, and use older bales first so nothing sits too long. Before feeding, give each biscuit a quick look and sniff. Sweet smell and green colour are good signs; mustiness, dust clouds, warmth or visible mould mean it belongs on the garden, not in the feed.

Special cases and at-risk horses

Some horses need their hay handled with extra care, and each case is best managed with your vet rather than guesswork. The forage-first principle still holds, but the type, amount and preparation shift depending on the horse. Here are the three groups that most often need a tailored approach, each led by the same advice: see your vet first.

Easy keepers, ponies and laminitis-prone horses

Easy keepers, many ponies and horses with a history of laminitis need low-sugar forage, carefully rationed, with the vet closely involved. The aim is to keep fibre flowing while keeping sugar and calories in check. Low-NSC grassy hay, fed through a slow feeder and soaked when appropriate, is the usual toolkit. These horses can founder on what looks like an innocent feed, so any change is a conversation with your Australian equine vet first. If a routine change has your easy keeper unsettled, gentle, vet-checked calming horse treats can be part of a settled routine, though always clear big diet changes with your vet.

Senior horses and poor teeth

Older horses with worn or missing teeth often struggle to chew long-stem hay and need help to keep fibre in the diet. When a senior cannot manage a hay net, soaked hay, chaff, soaked hay cubes or pellets and other softened forage alternatives can keep the fibre coming in a form they can eat. Quidding, weight loss and slow eating are the signs to watch. A senior losing condition is a prompt to involve your vet, both for a dental check and to plan a forage-based diet it can comfortably process.

Hard keepers needing condition

Hard keepers, the horses that struggle to hold weight, need more energy without losing the forage foundation. The first move is still forage, often with some good lucerne worked in alongside grassy hay, then hard feed and oils can add calories on top. The mistake to avoid is cutting forage to make room for grain, which trades gut health for short-term condition. Build up, do not swap out. If a horse stays thin despite plenty of good feed, that is a veterinary investigation, since dental problems, parasites and underlying illness can all be at play.

Frequently asked questions

How much hay should I feed my horse per day?

Most horses need forage equal to about 1.5 to 2.5 percent of their bodyweight in dry matter each day. For a typical 500 kg horse that is roughly 7.5 to 12.5 kg of hay daily. Adjust for workload, body condition and pasture, and confirm with your Australian equine vet.

Can a horse live on hay alone?

Many healthy adult horses at rest can live on good quality hay plus fresh water and a salt or mineral source. Hay often lacks some vitamins and minerals, so a ration balancer is commonly needed. Working, pregnant, young or unwell horses usually need more. Ask your vet.

What is the best hay for horses in Australia?

There is no single best hay. In Australia, grassy hays like Rhodes grass, oaten and meadow hay suit most horses, while lucerne is higher in protein and calcium for horses needing extra condition. Choose clean, mould-free, dust-free hay and match the type to your horse's needs.

Should I soak my horse's hay?

Soaking hay for around 30 to 60 minutes reduces dust and lowers water-soluble sugars, which helps horses prone to laminitis or respiratory issues. Soaking also removes some nutrients, so do not over-soak. Feed soaked hay promptly and discuss its use with your Australian equine vet.

How long can a horse safely go without hay or forage?

Horses are designed to graze almost continuously, and their stomachs produce acid constantly. Going more than about four to six hours without forage raises the risk of gastric ulcers and digestive upset. Aim for near-constant access to hay, using slow feeders to extend small, frequent meals.

Why is forage so important for a horse's gut?

A horse's hindgut relies on a steady flow of fibre to fuel the microbes that produce much of its energy. Constant forage buffers stomach acid, supports healthy gut movement, and lowers the risk of ulcers and colic. Sudden forage changes disrupt these microbes, so transition feeds gradually.

How do I change my horse's hay without causing problems?

Introduce new hay gradually. Australia's Agriculture Victoria advises changing feed over at least 3 to 5 days, and many owners take 7 to 14 days when switching to a completely new forage. A slow change lets the hindgut microbes adapt and lowers colic risk. Monitor appetite and manure.

The bottom line is the same one we started with. Forage is the foundation, and good hay, fed in plenty and kept clean, supports your horse's gut, teeth, mind and metabolism in ways nothing else can. The hard feed, supplements and treats belong on top of that base, not in place of it. This guide is general educational information from a treats company, not veterinary advice, and every horse is an individual. For anything specific to yours, your Australian equine vet is the person to ask.

References

1. RSPCA Australia. "What should I feed my horse?" RSPCA Knowledgebase. kb.rspca.org.au.
2. RSPCA Australia. "Should I stable my horse?" RSPCA Knowledgebase. kb.rspca.org.au.
3. Agriculture Victoria. "Feed requirements of horses" (Victorian Government; reviewed with Dr Charles El-Hage, University of Melbourne Equine Centre; updated 25 February 2026). agriculture.vic.gov.au.
4. Biosecurity Tasmania / DPIPWE. "Basic Nutrition for Horses" (Tasmanian Government PDF). nre.tas.gov.au.
5. Queensland Department of Primary Industries. "Feeding horses" (Queensland Government). dpi.qld.gov.au.
6. McGreevy, P. "How to feed a racehorse and keep him healthy." The Conversation (Australia). Professor of Animal Behaviour and Animal Welfare Science, University of Sydney. theconversation.com.
7. Murray Veterinary Services. "Equine Gastric Ulcer Syndrome (EGUS)" (Australian equine veterinary practice). murrayvets.com.au.
8. Vet Voice (Australian Veterinary Association). "Equine dentistry." vetvoice.com.au.
9. University of Queensland Veterinary Medical Centre (UQ VETS). "Equine metabolic syndrome (EMS) and laminitis." uqvets.com.au.
10. AgriFutures Australia (formerly RIRDC). "Equine Laminitis: Managing pasture to reduce the risk" (Publication 10/063, Commonwealth of Australia, 2010). agrifutures.com.au.
11. Cubitt, T. "Does soaking hay really reduce carbohydrate content?" Horses and People Magazine (Australia), 29 May 2018. horsesandpeople.com.au.
12. Layton, C. "Lucerne." Balanced Equine (independent Australian equine nutritionist). balancedequine.com.au.
13. Harris, P. et al. (2023). Feeding conserved forage to horses. Animals (MDPI), peer-reviewed (international scientific literature). pmc.ncbi.nlm.nih.gov.
14. Equine saliva and chewing duration. Acta Veterinaria Scandinavica, open-access peer-reviewed journal (international scientific literature). pmc.ncbi.nlm.nih.gov.
15. Sykes, B.W. et al. (2015). ECEIM Consensus Statement on Equine Gastric Ulcer Syndrome in adult horses (international veterinary consensus, overseas). pmc.ncbi.nlm.nih.gov.
16. Kentucky Equine Research. "How to Feed Horses: General Guidelines" (US-based, with an Australian arm; cited as overseas supporting context only). ker.com.