Principal Body System: Digestive
Definition: A long tube called the gastrointestinal (GI) tract and associated organs, i.e. salivary glands, liver and pancreas.
Function: Performs the physical and chemical breakdown and absorption of food for use by cells, and eliminates solid and other waste.
All dis-ease begins with the gut. So said Hippocrates. And all these centuries later, there's still no doubt about it. The digestive system is the Mother of all the Systems, and the large intestine the Mother of all Organs - everything starts with the gut.
A healthy gut is the ultimate gatekeeper of good health, and a healthy microbiome the game-changer; when the gut environment is out of balance, a malfunctioning body is the result. The gut system isn't just a tube where we shovel food in one end and wait for it to come out the other end - the gut has a massive job to do, in breaking down the food , separating out the healthful nutrients and getting them absorbed into the body to fuel it, while shuttling off the remaining waste to the main elimination exit point.
And it doesn't do all this by itself - the very function of the gut system relies entirely upon it's own army of elements; hydrochloric acid to kickstart the foregut into action; digestive enzymes to break down the protein, carbs and fats; microbes to break down the fibre, and fluids to lubricate and keep everything moving.
Without these essential elements, the gut system won't be able to do the very job it's meant to do, which is to keep the body alive. Without its own army it's no longer able to digest those essential nutrients we pay good money to feed to our horses to keep them healthy. Without them, so will begin a cascade of seriously chronic dis-ease. It really is as simple as this.
So, if you're looking to clear up the chronic symptoms that are chipping away at your horse's quality of life, there's only way to do it. Clean up the gut system. We need to look after our horse's gut health first and foremost, as the top priority, and here's where our C.A.R.E. programme comes in.
- Clean - clean and detox gut irritants and toxins.
- Activate - activate healthy digestion and the integrity of the intestinal gut lining by repopulating the beneficial gut microbiota.
- Restore - restore health with essential micronutrients into the diet.
- Enhance - enhance immunity - energy, strength and vitality.
The horse's digestion operates via enzymatic digestion in the stomach, or ‘fore-gut’, ahead of the large intestine, or ‘hind-gut’, made up of the cecum and two colons, where it's all about bacterial or microbial fermentation of fibre. This dual system works by the fore-gut dealing with most (over 50%) of the protein digestion and most soluble carbohydrate digestion. Fibrous sources such as grass and hay are digested 'microbially' in the hind-gut. And because our horses mostly eat fibre, keeping the friendly bacteria well populated in the hind gut is crucial.
Horses normally consume 2-2.5% of their body weight in dry matter each day, although if they’re on pasture 24/7, this can go up to over 3%. By adding processed feeds, the nutrient proportion from this will increase, so horses will reduce their total dry matter intake.
For enzymatic and microbial action to digest feed efficiently, the horse needs healthy teeth to grind feed to allow enzymes and bacteria to attack the plant cell walls of what he's eating. Thus, it goes without saying that horses teeth should be checked every year to ensure that they're wearing normally and are effectively grinding the feed.
Remarkably, the capacity of the stomach of the horse is small, about the size of a rugby ball and coming in at just 8-15 litres. So how can a horse consume large amounts of food or water? The emptying time of the stomach after filling is around 12 minutes, and the rate of passage down the small intestine is about 1ft/min - this means that food can go from the mouth to the cecum in about 1½ hours. The small volume of the stomach and rapid passage of food from the stomach is the reason horses eat almost continuously, thus the phrase ‘trickle feeders’. Total passage time is 2-3 days from when food is ingested until it is passed out.
NB. The foal and growing horse have undeveloped cecal and colonic digestion compared to the adult horse. There is very little microbial digestion before 3 months of age, so the foal requires a diet low in fibre and one that is easily digested in the fore-gut. Foals who are seen eating their mothers' manure are thought to be obtaining a bacterial culture necessary for future microbial digestion.
Feed the Flora!
Taking care of our horse's gut microbiome is crucial - for starters it improves nutrient absorption. But it's so much bigger than this - the microbiome literally runs the show. Around 80% of our horse's immunity is created by the gut microbes in the intestinal tract and this microbiota is the major regulator of the immune system- the difference between healthy and unhealthy relies entirely upon the gut microbiome performance.
Our part in nurturing a healthy microbiome is the first line of defence against many health issues. Our horses don't make their own gut microbes, so incorporating a probiotic into your horse's daily feed will help establish the colonisation of microbes, enhancing your horse's ability to digest and utilise the full benefits of the nutrients you're feeding.
Unfortunately, there are also certain medical treatments which can really mess with the gut ecology, such as antibiotics, bute and chemical wormers, which disrupt the relationship in a similar way that chemotherapy affects the human body. Chemotherapy wipes out perfectly healthy non-cancerous cells inside the human body along with the cancerous cells, annihilating the immune system. Similarly, antibiotics wipe out the gut bacteria, the bad bugs as well as the good bugs the body can’t live without.
A healthy gut system is absolutely essential for overall health and vitality - sounds obvious I know but an effective digestive process means your horse will absorb the nutrients you spend a fortunte on trying to get into them. The picture is so much bigger than this though; a healthy gut will also minimise the risk of laminitis and colic, and protect the horse against infections such as diarrhea-causing organisms like salmonella or clostridium.
A healthy, functioning digestive system is really straightforward to manage, provided we feed the right feed. However, the equine digestive system is extremely sensitive, and the concern is that it doesn't take much to upset the delicate gut environment; poor diet/dietary management, obviously, but stress can equally play an enormous part in affecting gut health. However, poor gut health can manifest itself in so many ways, from the obvious signs of loose stools to colic symptoms, from lack of overall vitality to allergies or significant pain.
For the full story on how critical a part the microbiome plays in overall health, see our separate chapter The Microbiome - the Missing Organ?
Leaky Gut Syndrome
Collectively the beneficial and pathogenic microbes outnumber the cells in the body by at least 10-1, so cultivating the beneficial gut bacteria is the first line of defence against many serious diseases.
We need to centre our attention on the good gut microbes (microbiota), on regulating the permeability or leakiness of the gut lining - this is the connecting factor. When the gut wall breaks and becomes permeable, when the gut bacteria are disrupted, or foods or environmental toxins which upset the gut lining are ingested, then toxins in the gut get across the lining into the bloodstream and triggers an inflammatory autoimmune cascade as the immune system goes into hyper overdrive.
Leaky gut affects the whole process for just about every medical condition, be it joint, skin, brain and so on; everything has to do with the gut and specifically the lining, which is a mere 1-cell thick, so you can appreciate just how vulnerable the gut lining is.
These days we have the knowledge and the tools to get the diet right, not just in fibre but in prebiotic fibre which changes the microbiota for the better and nurtures it to flourish, in order to increase its production of the very important byproducts to benefit health.
For our horses, it's fundamentally important that we look after the gut bacteria. We need to feed the right stuff to nurture it, and avoid the bad stuff that feeds the bad bacteria, which is a whole separate chapter in itself - see our FEEDING OUR HORSES chapter.
For the full story on leaky gut, see our separate chapter The Microbiome - the Missing Organ?
Here’s a thing – ulcers are there because the gut environment is already altered, usually due to either some form of stress, inappropriate feed, or stress caused by inappropriate feed.
Both these factors are the cause of why our horses – and us humans – get ulcers. Stress and/or the wrong food/food management destroy the gut environment, literally, which means that without a strong, healthy protective mucosal gut lining, the foregut (stomach) acid will leak and create a wound, aka an ulcer, because it’s almighty strong hydrochloric acid, same as a car battery.
Some quick stomach acid facts:
- Stomach acid is a prerequisite to healthy digestion – it’s there because it’s meant to be there. Without it, digestion would simply not occur.
- The breakdown and absorption of nutrients occurs within only a narrow range of acidity in the stomach.
- If there isn’t enough acid, the normal chemical reactions required to absorb nutrients is impaired.
Sounds simple enough, doesn’t it. Yet most of us have no idea how many vital roles stomach acid plays in the body, whether horse or human, and the drug companies know it. You can’t watch TV without seeing an advert for some chalky tablet to ‘calm’ the acid burn, especially after we've eaten a red hot, spicy curry.
The claim that the acid is causing the ulcers is a myth. The acid splash/leak is merely a side-effect of the stress/poor-quality feed which has caused the damaged gut. Remove the stressors or change the feed to a species-appropriate, focus on the gut microbiome and clean it up, make sure there’s continuous ad-lib forage, and let a horse be a horse with buddies, social interaction and allowed to express their natural behaviour, and we’ll very likely witness a remarkably quick, not to mention safe, natural recovery, without shovelling damaging symptom-blocking chemicals (PPIs) into our horses' already damaged digestive systems.
Probiotics and Prebiotics
Despite the similarity in their names, probiotics and prebiotics are not just two different forms of a similar supplement - they are actually two completely different types of digestive supplement with unique mechanisms of action on the equine gut. Probiotics promote the population of the 'good' microbes and bacteria; prebiotics are the foods that feed those good microbes and bacteria. Together they are fed to stimulate the growth and activity of the good bacteria that live in the horse’s gastrointestinal tract.
My personal choice? I feed Alltech's probiotic Yea-Sacc 1026, a live yeast culture based on Saccharomyces cerevisiae strain, alongside Brewers Yeast as a general prebiotic, a highly nutritious non-active yeast providing (almost) the full compliment of B vitamins (with the exception of B12, although there's the tiniest trace). If ever there was dire digestive compromise or risk of, I'd add BioMos as a prebiotic as it specifically binds to bad bacteria, e.g. salmonella/e.coli, and eliminates them.
We sell these items separately (INDIVIDUAL ITEMS) to add independently to feed. Look to add 2g/100kg bodyweight for YeaSacc, so for an average 500kg horse, add 10g. Brewers Yeast can be fed at around 20g daily/pony, 40g daily/horse. Alternatively, we combine them in some of our EquiVita range of mineral balancers.
General pointers for a healthy gut system
- Horses are herbivores and are designed to graze on a diverse range of fibrous, low-energy forages up to 20 hours per day - it needs to be diverse to create a diverse microbiome. They should receive a minimum of 60% of their dry matter intake from good quality forage (e.g. hay, grass).
- The best feed your horse can put in his mouth is grass. The second-best feed is hay, grass in its dried form. The bulk delivered by a fibrous grass/hay diet is a key weapon in avoiding colic because consistent gut-fill maintains a continuous level of digestive activity. Additionally, horses usually chew hay twice as long as grain. The more they chew, the more saliva is generated and mixed in, which helps buffer the GI tract against excess acidity.
- Unfortunately, domesticated living usually challenges the horse's sensitive digestive tract with inappropriate processed feedstuffs, irregular feeding schedules and ration portions that are far outside the norm of the natural plan. One of the primary reasons that horses colic is the difference between what the digestive system is meant to process and what it actually gets.
- Make changes in feed slowly over a period of 7-14 days and be careful about overfeeding manufactured feeds or grain prior to an event.
- Keep your horse moving – stabled horses are much more prone to gut issues than those who live out. Turnout with companions keeps horses happy, allows them social interaction and lets them eat their favourite food. Not only is the horse free to consume the ideal fibrous diet, but the simple, continual act of moving to eat, keeps the food moving along in the gut.
- To promote healing of the gut, this is where the right kind of bacteria comes into play. The right kind of bacteria will break down fibre in the diet into molecules that are really easily used by the gut cells as energy sources. So we have to make sure we have plenty of fibre and the right kind of bacteria in the gut to heal the gut, and then there are two essential amino acids you can use, especially if you're dealing with gastric ulcers or leaky gut.
· N-Acetyl L-Cysteine (NAC), the precursor to glutathione, arguably the most powerful antioxidant in the body, which replenishes glutathione production.
· Glutamine, a building block for proteins that maintain cellular health and tissue repair. During critical illness, trauma, intestinal disease, excessive loss of lean body mass, and extreme endurance exercise Glutamine is shown to be beneficial. Glutamine also works in synergy with NAC to help promote glutathione.
We've blended both these amino acids together as a gut support - see our GutAminos blend.
- Aloe Vera juice can help support the stomach and colon. It is high in digestible fibre, which gives it the properties of lowering bowel transit time, absorbing toxins in the bowel, supporting colonic bacteria, and soothing the digestive tract.
Aloe also contains a complex mixture of mucopolysaccharides (complex sugars) that nourish cells and support them in replicating. This property is especially important for gut acid. The polysaccharides can also be helpful for horses who have been on buffering agents or similar that destroy healthy bacterial populations in the gut and allow pathogenic bacteria to multiply.
Good quality Aloe juice can be found in most health food stores, and Aloe concentrate powder is also available. Add 50-100ml of Aloe to feed when your horse is displaying symptoms.
- Slippery Elm v Marshmallow Slippery Elm is a renowned gut-healing herb with similar properties to Aloe. However, the native populations of the Slippery Elm tree are suffering due to its popularity and the tree is now considered extremely rare and as a result, a protected species. The good news is that the herb Marshmallow can be suitably substituted for Slippery Elm because Marshmallow has almost identical properties and is so much more widely available, although of course we can supply both.
Add 50ml Aloe and 1 desertspoon of Marshmallow to feed or syringed directly into the mouth.
- Aloe and Marshmallow are not only beneficial for digestion in general but also support excess gut acidity as well. They can both be fed long term with no negative effects.
- Apple Cider Vinegar is also invaluable for gut health - not only is it a beneficial supporter of immunity, it's also rich in natural probiotics, beneficial enzymes and acids that help absorption of nutrients.