Why Probiotics and Digestive Enzymes are Important Feed Additives for Your Horse

Thirty years ago grazing typically provided approximately 30 or 40 different types of grasses and green plants with naturally occurring nutrients, beneficial bacteria and enzymes; today, grazing is limited to sometimes as few as four varieties of plants or grasses.

By Jessica Lynn

Probiotic is derived from the Greek word 'pro' meaning 'for' and 'biosis' meaning 'life'. Therefore 'pro-biotic' is, and means, the opposite of 'anti-biotic' (against life). Probiotics are, simply, 'live' beneficial (good) bacteria that do their work in the digestive tract. Probiotics and digestive enzymes can be fed as supplements to encourage the proliferation of certain beneficial bacteria and enzymes, to work in concert with the digestive process. There is a microbial balance that needs to be maintained throughout the horse's digestive tract, and though horses in the wild may naturally eat what is needed and avoid toxins, horses in domestic situations may not. Feeding live beneficial bacteria and digestive enzymes can help to maintain or create microbial balance, setting up the ideal environment for all these microorganisms to flourish, thus enabling and optimizing digestion and maximizing the health and well being of the animal.

Thirty years ago a horse grazing in a typical pasture would have had the choice of approximately 30 or 40 different types of green plants and grasses, each bringing its own specific nutrients essential for a balanced diet, and at the same time containing natural sources of digestive enzymes and naturally occurring beneficial bacteria. Today, in that same pasture, because of selective seeding, fertilizing, and herbicide spraying, etc. the grazing is limited to sometimes as few as four varieties of plants or grasses.

In this day and age, it is common that equine 'feedstuffs' contain soybean meal, plant protein by-products, molasses and other cereal type ingredients. These ingredients are mechanically processed, cooked, steamed, extruded, cubed or pelleted. All the processing coupled with extended storage often destroys essential enzymes. From all of this over-processing, depleted/ nutrient deficient soils, and stress, some equines are also beginning to suffer from food enzyme deficiencies that can, by themselves, lead to an array of non-specific related symptoms. Your horse's stomach requires digestive enzymes to begin the process of breaking down the feed, as only one part of the digestive process. As that feed is then delivered to the intestinal tract, specific types of bacteria are needed to continue the digestive process so that the body may absorb the nutrition found in that same food to maintain health and wellness and stay sound and active. Digestive enzymes work with the gastric juices to start the breakdown, then the bacteria make the feed into usable, absorbable compounds.

One of the most common sources of digestive disturbances in horses is 'stress', which may be brought on by such things as sudden changes, moving, competition, psychological stress of travel and training, breeding and pregnancy, worming, parasites, vaccines, viruses, and injury. 'Stress' can also be created by unusual or unseasonable weather conditions, alterations in environment, and lesser quality feeds and water. Without the proper digestive enzymes and beneficial intestinal bacteria being in place, food passes through the system not being able to be 'fermented' in the way it was intended and instead of being digested remains undigested. This undigested food passing through the gastro-intestinal tract may then lead to situations such as colic or colic-like symptoms, bloat, and founder, or may set up an ideal parasitic environment, and may even increase the possibility of the horse developing feed related allergic conditions.

Antibiotics, of course, wreak havoc by destroying bacteria in the body indiscriminately and sometimes permanently. The digestive system bacteria are temporarily eliminated until they are re-introduced into the digestive tract by specific foods or supplementation and given the chance to proliferate, flourish and attain balance once again. Unfortunately, the microflora and microbial balance in a horse can be upset far faster than it can be restored; the effects may not show up immediately and may last a long time. A horse's beneficial intestinal bacteria being destroyed or depleted also alters the pH of this environment, further affecting digestion and the horse's overall health and well-being.

It is interesting to note that some owners use common probiotics themselves (in the human forms such as yogurt, kefir, or liquid acidophilus) and have experienced some of the key benefits of friendly beneficial bacteria, so are now beginning to understand the value of the bacteria found in these nutritional supplements for their animals' health, well being and longevity. Some of the live bacteria found in yogurt and kefir products are similar to those in the probiotics for animals, but at differing levels, and are delivered for human use in dairy products. You cannot safely feed yogurt or milk (dairy) products to foals or horses, or any herbivores, because they were not designed to ingest dairy products and, more important to know, horses are 'lactose-intolerant' (they do not have the ability to digest the lactic acids in dairy) so they should NEVER be given 'dairy' products.

However, there is an exception to that rule which is bovine colostrum. Colostrum is the 'pre-milk' liquid produced by all mammal mothers shortly after giving birth. Mother Nature intended it to provide immediate immunity to harmful bacteria and viruses for the baby’s intestinal tract. Bovine colostrum contains over 37 different and important natural immune factors along with more than 8 growth factors, including IGF-1 (Insulin-like Growth Factor-1), GH (growth hormone) and TGF-B (Transforming Growth Factor BETA), which work together in a specific balance to combat illness, assist in healing tissues and promote health. Recent medical findings have determined that bovine colostrum contains natural immune and growth factors that are not specific to cattle; therefore making dairy cows the 'universal donor' of colostrum for most other mammals including adults and children, horses, cats and dogs.

The use of probiotics is becoming more commonplace, occasionally coupled with digestive enzymes, in equine diets. They work well together - they are mutually supportive, and in fact, certain live bacteria naturally produce certain enzymes also valuable to the digestive process. What I have found, however, is that not many owners understand how these products benefit their animals and that there are very few products on the market that contain 'guaranteed' bacterial/ microbial counts to provide their animals with the most consistent, highest quality beneficial bacteria and microbes per serving.

To fully understand the role of probiotics, as well as digestive enzymes, in your horse’s diet it is important to have a simple or even basic understanding of the equine digestive system: When a horse eats, his food begins an approximate 100-foot journey through the digestive tract. Food is ground by the teeth and mixed with enzymes in the saliva, starting the digestive process. The food then mixes with digestive juices as it enters the stomach. Although the stomach is relatively small compared to the horse's size, it is one of the most important areas for initiating the breakdown of food into utilizable nutrients using digestive enzymes and stomach acids. Very little absorption takes place in the stomach, with the major part of nutrient absorption occurring via the small intestine and a lesser amount via the cecum and large intestine. As the food passes through the stomach it enters the small intestine. The small intestine is the area where most soluble carbohydrates are absorbed along with minerals, fats and proteins. Insoluble carbohydrates that are not so easily digested, as well as any undigested soluble carbohydrates, are then passed to the cecum, which is the 'fermentation vat' situated before the large intestine. This is where the majority of the bacteria are found.

The purpose of the bacteria in the cecum is to break down into viable, usable nutrients the undigested food passed from the stomach and small intestine. A large array of bacteria/ microorganisms is needed for this to happen efficiently and effectively. The action of these bacteria within the cecum allows the food fibers to be broken down into volatile fatty acids that can then be absorbed and used not only as an energy source by the horse but to help meet his vitamin and other nutrient requirements. (Imagine, if you will, millions of little "Pac-Man" type creatures chomping away at the undigested feed as it is passing through the intestinal tract.)

The purpose of the microbial fermentation process is it further breaks out and releases the nutritional components in the ingested feed, some of which are microbial proteins from the digestive enzymes, along with other naturally occurring vitamin compounds such as vitamin K and B-complex. The concept of microbial fermentation occurs to some extent in all animals that eat foods of plant origin, including horses and humans. Horses (as well as some humans) depend largely or in some cases entirely on fibrous plant materials (hays, plants, and vegetables), so while humans rely on the stomach and large intestine, horses rely on the cecum for the fermentation and microbial breakdown to occur.

The population of beneficial microorganisms in the cecum remains relatively 'stable' under 'normal' circumstances and conditions. As long as a horse is never stressed, never needs to be wormed, never has an abrupt change in feed, and never needs antibiotics, then the balance should remain un-altered and remain 'stable'. The reality is that our horses do have stressful events, do get antibiotics occasionally, do have significant feed changes (including each different load of hay we buy), and they will be wormed from time to time.

There are three kinds of bacteria: 'good' (beneficial), 'neutral', and 'bad'. The horse needs a balance of all three, but there must be enough good to keep the bad in check. As long as the balance of good and bad bacteria remains constant and the gastro-intestinal tract is stable, the horse remains healthy. When the balance is upset, the horse may eat, but may not be able to digest properly or assimilate the nutrients he needs from his food. When this occurs it may begin to show up as a dull coat, skin conditions, inability to maintain weight, slow foot growth or other medical conditions including diarrhea.

There are numerous specific horse-friendly beneficial bacteria that are selected by microbiologists and are grown in live yeast cultures (not to be confused with Baker’s or Brewer’s yeast), usually in a base of molasses, sorghum, and ground corn or soybean meal. These microorganisms are grown using a fermentative vat type process and are monitored closely during this process.

One of the most highly fermentative yeast strains used is Saccharomyces cerevisiae, which is blended with active lactic acid bacteria, microencapsulated Lactobacillus acidophilus and Streptococcus faecium. Then microencapsulated Bacillus subtilis and digestive enzymes including amylase, protease and cellulase are also added. These yeast cultures are found to have naturally rich amounts of enzymes including glucanase, amylase, lipase, and protease, as well as amino acids, vitamin B complex, and fatty acids. During this growing process the bacteria are tested for their non-pathogenic properties, speed of growth in the fermentation process, and their attachment abilities to stay and do their job in the horse’s intestine and not just pass through to be taken to the manure pile.

Therefore the supplementation of digestive enzymes coupled with live beneficial bacteria (probiotics) is an excellent way to support the whole digestive process, from stomach to large intestine, thereby supporting the entire horse.

Digestive Enzymes

Enzymes are one of the most important factors for beginning the digestive process. Single enzyme products are however less effective then multi-enzyme products because multiple enzymes are needed, especially in regards to horse feed, to work 'synergistically' rather then targeting only one specific feed or ingredient (i.e. a protein). Enzymes are functional protein molecules that can catalyze and accelerate the rate of feed digestion and are especially critical for the digestion of intact feed materials entering the horse's stomach. Most enzyme products, currently offered by manufacturers, for animal feed purposes, are produced by fungi rather than live beneficial bacteria. The exception is Alpha Amylase, which is bacterial in origin and one of the more common 'single enzyme' products. Fungi prefer a lower pH than bacteria, and will produce some enzymes with a lower pH preference, however, a wider spectrum of digestive enzymes is needed to increase nutrient digestibility. The horse needs most of the common digestive enzymes as well as some others, which include:

Alpha Amylase - Breaks down complex and simple carbohydrates found in grains and some grain-rich hays such as oat and forage type hays into easily digestible simple sugars
Protease - Digests the protein, especially found in alfalfa, timothy, and other protein-rich hays, into peptides and amino acids
Cellulase - Splits the Beta 1,4 glucose linkage in cellulose fiber, found in all plant-origin foods, into a readily available form of sugar called glucose
Lipase - Digests naturally occurring and other fat source additives such as rice bran into absorbable forms of fatty acids and glycerides
Beta-Glucanase - Breaks down beta-glucan - long chain carbohydrate (arabinose, xylose and ribose) - found in the plant cell walls, which protects nutrients as they pass through gastric acids to be safely released for absorption in the intestines
Phytase - Aids in utilization of normally indigestible organic phosphorus found in plant materials and flax seed and other oil seed meals
Xylanase - Part of a primary enzyme system which is required to break down the lignified cell wall core of cellulose type plant materials found in hays and other feed – the cell walls of the plant material encapsulate important nutrients and therefore must be broken down by exposure to digestive enzymes and their processes for them to be utilized and absorbed in the intestine

Microencapsulated Live Beneficial Bacteria

Beneficial bacteria, including Lactobacillus acidophilus, Enterococcus faecium, and Bacillus subtilis are beneficial microorganisms administered orally to assist in replenishing essential microflora that have been proven to decrease the incidence of gastrointestinal disorders. Beneficial bacteria, especially Lactobacillus sp. (lactic acid bacteria), can produce specific anti-microbial substances that have been observed to inhibit the growth of some pathogenic microorganisms including Escherichia coli, Staphylococcus aureus, and Salmonella sp. These live beneficial bacteria and microorganisms are most effective to use during periods of disease or stress and following parasitic prevention programs or antibiotic treatment, after which few, if any, lactic acid bacteria may be present.

Supplemental live beneficial bacteria cause no side effects or possible microbial mutation. It is important to note that they are naturally occurring friendly live microorganisms and not drugs. It is also important that certain supplemental live beneficial bacteria destined for the cecum and bowels be microencapsulated to enable them to travel through the stomach acids and reach the hindgut intact, where they are then released to do their job. If certain live beneficial bacteria destined for the cecum and hindgut were directly fed unencapsulated, 90 percent would be destroyed in the acidic stomach environment with some being destroyed by pathogenic bacteria that also live there. However, when micro-encapsulation of the live beneficial bacteria is used, only 10 percent of the beneficial bacteria are destroyed, leaving the remainder to pass through to be released into the intestinal tract.

The microbial balancing act is necessary to maintain health, and it can be accomplished by adding to the feed, on a daily basis, many live beneficial bacteria and enzymes. Animals do not stop naturally producing their own digestive enzymes and intestinal bacteria if they are fed a 'natural source' with their daily feed. Feeding probiotics and enzymes is a preventive therapy; when a horse is given a balanced source it complements and ensures that the horse is efficiently and effectively digesting his feed for maximum absorption of nutrients. Digestive enzymes along with probiotics assist the horse to utilize more of his usual and daily feed rations by supporting the entire digestive process.

Probiotics also provide a way of limiting the number of harmful bacteria, parasitic infestations and pathogens in the digestive system, as well as their ill effects on the horse's overall health and well-being. The equine athlete, backyard horse and breeding stock all have certain nutritional requirements in order to support their health. All benefit from a well-balanced probiotic/ digestive enzyme supplement added to their daily feed ration, because they all share common 'stress' factors that are known to cause digestive disturbances.

Many manufacturers do not offer multiple digestive enzymes, nor do they 'guarantee' the microbial populations, or the 'live' and beneficial bacteria counts of their products - two of the most important factors to consider when purchasing a product. The best products will contain a balanced blend of digestive enzymes (each must be listed on the label), live yeast cultures, and/or beneficial microorganisms. A limited number and limited variety of beneficial microorganisms denote an inferior product, as does the absence of micro-encapsulation of the live beneficial microorganisms and the presence of sugar or artificial sweeteners, inert or non-nutrient-type fillers, colorings, artificial flavorings, and preservatives.

There is no exact or 'right way' to feed probiotic/ digestive enzyme formulas. They do not have to be fed daily. However, for the best results and for the good of the horse I do recommend feeding them on a 'regular' if not daily basis. What do I feed? I personally mix Probiotics Plus® (the probiotics/ digestive enzymes formula I prefer sold by Tobin Farms and manufactured by Cenzone Tech) with my horse's daily 'goulash', which consists of Missing Link® (a whole food product by Designing Health), Source® (a kelp meal), one cup of non-stabilized rice bran, and one-half to one cup of dry COB (whole grain corn, oats, and barley).

Probiotics Plus® was developed with the assistance of a holistic veterinarian, Dr. Anne Smith of Cave Creek, AZ who wanted and needed for her clients a full line of products that are pleasant-tasting and species-specific (horse, dog, and cat formulas), each with specific enzymes and guaranteed beneficial microbial counts. Therefore, each contains specific concentrated blends of live beneficial bacteria, yeast cultures, and multiple digestive enzymes including organic minerals and anti-oxidants, formulated to maximize intestinal flora and digestive efficiency. They are designed to be used as a daily topping or dressing and are meant to complement your animals' feed rations, not replace them, to assist them in the absorption and utilization of what you already feed.

All horses seem to benefit from the mineral fortification that can be found in most grain type feed formulas. However, there is a difference in absorption in the type of minerals used which consumers need to be cognizant of. "Minerals are the requirement of all metabolic processes in the animal’s body and the deficiency of some minerals can lead to poor performance. Minerals in feed supplements are available in both organic and inorganic forms. Inorganic forms of minerals consist of sulfates, oxides, and carbonates, these forms are less expensive and most commonly added; however, high concentrations of inorganic minerals can interact with other feed ingredients, thereby decreasing their bio-availability and bioactivity. Organic forms of minerals on the other hand are usually linked to an amino acid carrier where they are 'escorted' across the stomach of the digestive tract with greater efficiency." (Feedstuffs 1993) Therefore, that also becomes an important consideration when researching products for your horses.

It has been my experience that all horses, from backyard to performance or breeding stock, from the eldest herd member to the tiniest foal, benefit from being fed probiotic/ digestive enzyme formulas regularly. It has also been my experience that breeding mares fed a probiotic/ digestive enzyme formula prior to breeding and during their pregnancies are healthier and stay healthier.

The ability to produce a healthy foal with the potential to develop into a fine athlete is the goal of any breeder. At birth a foal has over 40 percent of its skeletal structure already developed. If a brood mare does not receive adequate nutrition especially during the last trimester then the foal's skeletal system may be compromised as it will have an inadequate supply of minerals and vitamins critical for bone and cartilage development. A foal whose mother was fed a probiotic/digestive enzyme formula would benefit from receiving the 'maximum' amount of nutrition available in utero for optimal development and growth, and, because the mare is absorbing the maximum amount of nutrients in her food, she is not being 'depleted' during her pregnancy or when nursing the foal. The added benefits and results I have also observed have been very healthy and lively foals that stand and nurse almost immediately with beautiful coats, good feet and good strength at birth. I give our foals an oral paste probiotic at 12 hours after birth, and on the 4th and 10th day, to ensure that the intestinal tract is off to the best start possible. There are numerous paste probiotics on the market, but the key is finding the ones with the guaranteed live microbial/ bacterial counts, with no preservatives, artificial coloring, or flavoring added.

I know of many people who are now using a variety of probiotic products and are feeding the probiotics/ digestive enzymes formulas daily in the manner in which I do so their horses receive the best benefits. They have consistent energy levels and weights, good hoof growth, improved health with few if any digestive disturbances, healthy beautiful coats, and limited or no parasitic infestations. I have recently been informed that the UC Davis School of Veterinary Medicine is doing a study on probiotics and horses, which tells me that there will be more information available in the future. Because of my experiences, my guess is that they will come out supporting their use.

I also have friends and customers who only feed probiotics/ digestive enzyme formulas for 5-7 days after worming, or after a round of antibiotics as a replenishing/ preventive measure (like many women do by ingesting yogurt or kefir after taking a round of antibiotics so as not to develop a vaginal yeast infection because their various natural bodily flora had been compromised by the drugs and needed to be re-established/ repopulated). These same friends and customers also feed the probiotic/ digestive enzyme formulas just prior to travel or competition, or during stressful situations such as schooling or training as a preventive measure. Some have told me they double the dose during competition, feeding the normal amounts at other times, and also have good results.

In the process of developing our formulas we have provided products to some of the top horse breeders and trainers in our area to try. When I have checked back to find out their results it was interesting to note the different ways in how they in fact had used them. One top, award-winning breeder/ trainer used them during conditioning and training of young horses (2-4 year olds). Another was using the formula only for horses they used for breeding or for horses training for show that had trouble maintaining weight even after their teeth had been floated. Yet another was using it for the mares and foals during weaning, which as we all know is a very stressful time. This particular breeder, who would have upwards of 30-50 foals at their facility, per year, had re-occurring illnesses and health problems during weaning time for several years. A large number of their weanlings would come down with upper respiratory illnesses or diarrhea brought on from the stress of being taken from the mares. This breeder has said they now see less 'stress' related illness in the weanlings and they have far fewer vet calls with less need for using antibiotics because they are giving the babies the probiotics/ digestive enzymes during those times with notable results.

Some people believe that if you feed probiotics/ digestive enzymes all the time that the horse loses his ability to naturally produce his own. We have not found this is to be the case. However, what we have found is that the horse has been losing his own 'natural' ability to produce all that he needs to properly digest and absorb the nutrients from his food, and/ or his ability to recover what he needs because, let’s face it, for the most part he is fed an 'un-natural' diet of stored hays and over-processed feed stuff which has lost the naturally occurring enzymes the horse needs. In some areas of the country horses are kept in barns in small stalls with no pasture available during winter months, some never get pasture because they are in 'show barns', some are on western show, barrel racing or rodeo circuits and some are just fed straight alfalfa, with no variety of hays, which seems to be the case especially in southern California. Other more fortunate horses may get a variety of grasses and hays but may be given monthly or daily wormers, and/or rounds of antibiotics, or are vaccinated regularly because of barn, boarding facility, or show requirements. All of these alter the horse's ability to properly digest and absorb the nutrients from his food. While it may be true that you do not 'need' to feed probiotics on a daily basis, it is advisable to feed them at least as a preventive or rehabilitating/ replenishing measure as mentioned earlier.

I would like to leave you with this thought:

"Whatever the nutritional potential of a food, its contribution is nonexistent if it does not pass the test of absorption. Those nutrients that have not been transferred through the intestinal mucosal cell to enter the circulation have, for all nutritional intent and purpose, never been eaten. The variety of nutrients from the organism's environment that have been made available by absorption must be transported through the circulatory system to the aqueous microenvironment of the cells. There, they serve their ultimate purpose: participation in the metabolic activities in the cells on which the life of the total organism depends." (Nutrition: An Integrated Approach; p. 283)

About the author:
Jessica Lynn is an author who has researched and written articles on human and animal nutrition. She has been involved in preventive health and nutrition for humans and animals since early childhood. Jessica consults and works with Cenzone Tech of San Marcos, CA as an equine nutritional products researcher and designer, and their resultant products are based upon the knowledge and expertise of allopathic and holistic veterinarians, nutritionists, microbiologists, zoologists, immunologists, herbologists and other specialists in the field of animal nutrition. Jessica lives in San Diego County with her cats and 4 Border Collies. She raises and schools Arabian horses in a natural, intuitive and progressive manner. Jessica can be reached at 760-752-7831 or via email at StarFyreFarms@aol.com.

For more information:

For information or to purchase probiotic/digestive enzyme products for human, equine, canine and felines contact:

Tobin Farms
106 Hughes Rd.
PO Box 529
Mapleton, ME 04757

For technical or scientific information contact:

Melissa Erickson
Cenzone Tech
2110 Low Chaparral
San Marcos, CA 92069