Visceral+

Choline is an essential nutrient that functions as a structural component of cell membranes, a methyl group donor in metabolic reactions, and a precursor for the neurotransmitter acetylcholine. It plays critical roles in liver function, lipid transport, and nervous system communication.

In equine nutrition, choline is considered a vitamin-like compound closely associated with the B-vitamin group. It contributes to normal fat metabolism and supports hepatic and muscular energy balance. Although horses can synthesize some choline endogenously, requirements may increase under metabolic stress, high performance demands, or when diets are low in methyl donors such as methionine or folate.

Choline also influences intestinal and hepatic lipid metabolism and may contribute to maintaining normal gut function through its effects on phospholipid synthesis and membrane integrity. Supplementation with bioavailable forms such as choline chloride or phosphatidylcholine supports these physiological roles in horses.

Docosahexaenoic acid (DHA) is a long-chain omega-3 fatty acid that supports inflammatory balance, joint mobility, cardiovascular health, and immune resilience. It is a structural component of cell membranes and contributes to normal signaling in tissues such as the brain, retina, and muscle.

In the horse, DHA and eicosapentaenoic acid (EPA) are the primary omega-3 fatty acids that generate bioactive compounds—resolvins and protectins—which help regulate inflammation and oxidative stress. Because the conversion of alpha-linolenic acid (ALA) from plant sources to DHA and EPA is inefficient, direct supplementation with marine-derived DHA (such as from microalgae or fish oil) provides a more effective source of these functional lipids.

DHA supplementation has been shown in equine research to support metabolic health, respiratory function, and post-exercise recovery, particularly in horses with higher oxidative or inflammatory demands. In horses, dietary supplementation with DHA has been shown to improve insulin sensitivity and support healthier insulin levels. This fatty acid also benefits digestive health by modulating inflammation in the gut and supporting a healthy gastrointestinal lining. It can also help promote a balanced microbiome. Microalgal DHA offers a sustainable, contaminant-free source suitable for performance and metabolic support.

Dried yeast extract is produced from the soluble components of yeast (Saccharomyces cerevisiae) and provides a concentrated source of mannan-oligosaccharides (MOS), beta-glucans, nucleotides, and peptides. These bioactive fractions support a balanced hindgut microbiota, efficient nutrient absorption, and optimal digestive and immune function.

Beta-glucans and MOS from yeast help maintain microbial stability and gut barrier integrity by promoting beneficial bacteria and reducing pathogen attachment to the intestinal wall. The naturally occurring nucleotides in yeast extract play a key role in supporting rapid epithelial turnover and cellular regeneration in the intestinal lining, especially during periods of stress or high metabolic demand.

Through its combined prebiotic, immune-supportive, and trophic effects, dried yeast extract contributes to digestive resilience and gastrointestinal health in performance and metabolically sensitive horses.

L-Glutamine is the most abundant amino acid in the horse’s body and serves as a primary fuel source for rapidly dividing cells, particularly enterocytes that line the gastrointestinal tract. It plays a central role in maintaining gut integrity, supporting nutrient absorption, and promoting tissue repair following stress, illness, or intensive training.

Glutamine also contributes to protein synthesis, acid-base regulation, and immune cell function. During periods of high metabolic demand or inflammation, endogenous glutamine production may not meet physiological needs, making supplementation beneficial for maintaining digestive and muscular health.

In equine nutrition, glutamine is often included to help maintain mucosal integrity, reduce oxidative stress, and support normal inflammatory balance within the digestive tract—key factors for horses recovering from stress, transportation, or gastrointestinal upset.

Lactobacillus acidophilus is one of the best-studied lactic acid bacteria used in equine probiotics. It naturally occurs in the horse’s gut and helps maintain a balanced, diverse microbial community by producing lactic acid and other metabolites that support a stable hindgut environment.

This species ferments carbohydrates to produce lactic acid in controlled amounts, contributing to a healthy gut pH that discourages the growth of undesirable microbes. L. acidophilus also adheres to the gut lining, competing with harmful bacteria for space and nutrients, and helping support the integrity of the mucosal barrier. These actions contribute to normal digestive processes and healthy immune function.

Research shows that L. acidophilus can promote the production of beneficial short-chain fatty acids such as butyrate, which supports gut lining health and efficient nutrient absorption. In horses, supplementation with L. acidophilus often alongside L. casei has been associated with improved protein and fibre digestibility, more efficient fermentation, and overall support for healthy hindgut function.

Lactobacillus casei is a lactic acid–producing bacterium known for its ability to tolerate a wide range of acidity and temperature conditions. It naturally occurs in the equine digestive tract and is commonly paired with L. acidophilus because the two species complement each other’s growth and activity.

As a direct-fed microbial, L. casei helps support a balanced hindgut microbiome by competing with undesirable microbes for space and nutrients, a process known as competitive exclusion. This strain can adhere to the gut lining and produce bacteriocins—natural antimicrobial peptides—that help maintain a healthy microbial environment. These actions support normal digestive function, nutrient utilization, and gut barrier integrity.

Research in horses indicates that supplementation with L. casei, particularly when combined with other probiotic species such as L. acidophilus, can enhance fibre and protein fermentation, contributing to improved nutrient absorption. Studies in other species also demonstrate that L. casei can help maintain microbial balance during periods of stress and provide antioxidant activity that supports normal immune responses.

Lactobacillus farciminis is a lactic-acid–producing bacterium that supports healthy fermentation in the equine hindgut. This species helps break down structural fibres such as cellulose and hemicellulose, releasing short-chain fatty acids that the horse can use as an energy source.

By producing lactic acid in controlled amounts, L. farciminis contributes to a stable hindgut pH and helps maintain an environment that limits the proliferation of undesirable microbes. In vitro work also shows that this strain can inhibit certain harmful bacteria, including some E. coli species, while providing antioxidant activity that supports normal immune function.

Research using hindgut samples from horses supplemented with L. farciminis demonstrates improved fibre fermentation and enhanced gas production patterns associated with active, healthy microbial activity. Additional studies suggest this strain can adhere to the gut lining, helping to support a resilient mucosal barrier and overall digestive tract integrity.

Lactobacillus fermentum is a Gram-positive lactic acid bacterium that naturally forms part of the horse’s gut microbiota. Like other lactic acid bacteria (LAB), it is valued as a probiotic because it can survive exposure to gastric acid and bile, allowing it to reach the hindgut where it contributes to a balanced microbial community.

L. fermentum produces natural antimicrobial compounds such as lactic acid and hydrogen peroxide that help limit the growth of undesirable microbes through competitive exclusion. Research in other species shows that this strain can block pathogen attachment to gut tissues and promote a more favourable composition of gut bacteria, supporting normal digestive function and microbial stability.

This species has also demonstrated antioxidant activity in experimental models, helping support normal inflammatory pathways and gut tissue health. By contributing to efficient fermentation, supporting the mucosal barrier, and enhancing nutrient availability, L. fermentum plays a meaningful role in maintaining overall digestive and immune function in horses.

Lactobacillus plantarum is a beneficial lactic acid bacterium (LAB) that naturally inhabits the equine digestive tract. It is commonly used in equine probiotic formulations because it can withstand the acidic conditions of the stomach and help maintain a balanced hindgut microbiome.

Research shows that L. plantarum supports normal digestive function by enhancing fibre and protein fermentation and by helping the gut microbiota break down nutrients more efficiently. Certain strains, including the LF4 strain, have demonstrated the ability to inhibit harmful bacteria through competitive exclusion and to provide antioxidant activity that supports normal immune responses.

Direct-fed microbials like L. plantarum also contribute to maintaining a stable hindgut environment by helping regulate microbial populations and supporting the production of beneficial fermentation by-products. Preliminary studies in animals suggest that long-term supplementation with L. plantarum may help support healthy energy metabolism and overall physiological resilience during exercise.

Lecithin is a naturally occurring mixture of phospholipids that supports the structure and function of cell membranes throughout the body, including those that line the gastrointestinal tract. Phosphatidylcholine, a major component of lecithin, plays an essential role in maintaining the protective mucus layer that shields the stomach lining from acid and mechanical stress.

By supporting the integrity of the gastric mucosa and normal lipid emulsification, lecithin contributes to a healthy gut barrier and balanced digestive environment. Its surface-active properties help stabilize mucus secretions, promoting mucosal hydration and normal barrier function.

Lecithin also provides a source of choline, an essential nutrient that supports lipid metabolism, liver function, and cellular membrane synthesis. In Visceral+, lecithin helps maintain gastric comfort and supports digestive resilience under dietary or performance stress.

Magnesium is an essential macro-mineral involved in hundreds of enzymatic reactions that regulate energy metabolism, nerve transmission, and muscle contraction. It supports bone integrity, cardiovascular function, and normal insulin sensitivity in horses.

In muscle tissue, magnesium contributes to relaxation following contraction, helping to maintain normal muscle tone and reducing the risk of cramping or tightness. It also plays a role in maintaining a calm temperament by supporting balanced nervous system activity, particularly in horses prone to stress or excitability.

Magnesium oxide is a highly concentrated inorganic source of magnesium commonly used in equine diets. It provides a bioavailable and cost-effective way to maintain optimal magnesium levels, especially for horses with limited access to fresh forage or those losing electrolytes through heavy sweating or training.

Mannan-oligosaccharides (MOS) are complex carbohydrates derived from the outer cell wall of yeast (Saccharomyces cerevisiae). They function as prebiotics that help maintain a balanced hindgut microbiota, support mucosal integrity, and promote optimal digestive function in horses.

MOS can bind to certain pathogenic bacteria, reducing their attachment to the intestinal lining and supporting a healthy microbial environment. These actions contribute to improved nutrient absorption and overall digestive resilience. In addition, MOS contains beta-glucans that support normal immune modulation and gut barrier function.

Mad Barn uses Bio-Mos^® from Alltech^® as the source of MOS in our formulations. Bio-Mos^® is derived from a proprietary yeast strain and has been evaluated in over 700 research trials, including peer-reviewed studies in horses and other species.

Marshmallow root (Althaea officinalis) is a botanical ingredient rich in mucilage, a complex mixture of polysaccharides that forms a soothing gel when hydrated. This mucilage supports digestive health by coating and hydrating the gastrointestinal lining, helping to maintain mucosal integrity and normal tissue resilience under acidic or stressful conditions.

The demulcent properties of marshmallow root help maintain gastric comfort and support the natural defense mechanisms of the stomach and intestines. Its bioactive compounds also contribute to antioxidant protection, which supports normal cellular function within the gastrointestinal tract.

Marshmallow root is included in Visceral+ to help support normal mucosal hydration, barrier integrity, and overall digestive comfort in horses exposed to dietary, environmental, or training-related stressors.

Meadowsweet (Filipendula ulmaria) is an herb that supports normal inflammatory balance and helps maintain the integrity of the gastrointestinal mucosa. It contains phenolic compounds such as salicylates, flavonoids, and tannins that contribute to its soothing and gastroprotective properties.

These constituents help support normal prostaglandin activity and mucosal defense, maintaining comfort and resilience in the gastric lining under conditions of acid exposure or dietary stress. Meadowsweet also provides antioxidant activity that supports cellular health and overall digestive function.

By promoting normal inflammatory responses and supporting gastric tissue integrity, Meadowsweet contributes to overall digestive comfort and well-being. It is included in Visceral+ to help maintain a healthy gastric environment in horses under stress or in training.

DL-Methionine is an essential sulfur-containing amino acid that serves as a building block for proteins involved in metabolism, growth, and tissue repair. Because horses cannot synthesize methionine internally, it must be obtained from feed or supplementation. It is often identified as the second-most limiting amino acid in equine diets, meaning insufficient methionine can restrict overall protein synthesis even when other amino acids are present in adequate amounts.

Methionine supports the formation of structural proteins such as keratin and collagen, contributing to strong hooves, healthy skin, and a glossy coat. It also plays a critical role in maintaining connective tissue integrity, supporting joints, ligaments, and tendons. In the nervous system, methionine assists in the production of neurotransmitters such as serotonin and helps support normal mood and focus.

Biochemically, methionine acts as a precursor for several important compounds, including taurine, L-carnitine, and cysteine. It is also required for the synthesis of S-adenosylmethionine (SAMe), a key methyl donor involved in cellular metabolism, detoxification, and liver health. Through its conversion to cysteine and subsequently glutathione, methionine supports antioxidant defense and helps protect tissues from oxidative stress.

According to the NRC’s Nutrient Requirements of Horses, a 500 kg (1,100 lb) horse at maintenance requires approximately 7,500 mg of methionine per day. Supplementation may be beneficial for horses on high-fiber or low-protein diets, those in heavy training, or horses needing nutritional support for hoof growth and coat quality.

Milk Thistle (Silybum marianum) is a botanical source of silymarin, a complex of flavonolignans including silybin, silychristin, and silydianin. These compounds are known for their antioxidant activity and their ability to help maintain normal liver function and metabolic balance. Milk thistle has been extensively studied in both human and veterinary contexts for its role in supporting hepatic health, antioxidant defense, and normal inflammatory processes.

In horses, silymarin helps protect hepatic tissue from oxidative challenges associated with exercise, diet, and environmental factors. It supports normal detoxification pathways by stabilizing cell membranes and promoting the regeneration of hepatocytes. Research in horses indicates that silibinin, the primary active component, is bioavailable and well-tolerated, supporting its use in equine nutrition. Its actions may also assist in maintaining healthy immune and inflammatory balance, contributing to overall well-being in horses exposed to training or metabolic stress.

Peppermint (Mentha × piperita) is an aromatic herb from the mint family Lamiaceae that supports normal digestive function. It provides bioactive compounds such as menthol and menthone, which exhibit antispasmodic activity and help maintain smooth muscle tone within the gastrointestinal tract.

By supporting normal gut motility and easing transient digestive discomfort, peppermint contributes to overall gastrointestinal comfort. Its carminative and soothing properties help maintain healthy intestinal function in horses receiving high-fiber or high-concentrate diets.

In addition to its functional benefits, peppermint provides a natural, palatable flavor that enhances feed acceptance, making it a useful ingredient in formulations designed to support gastric and hindgut health.

Saccharomyces cerevisiae 1026 is a live yeast strain used as a probiotic to support hindgut health and digestive efficiency in horses. It promotes a stable hindgut environment by helping maintain optimal pH and fostering the growth of beneficial cellulolytic bacteria that aid in fiber fermentation.

This yeast strain has been shown to enhance nutrient digestibility, particularly for fiber and phosphorus, and to support normal microbial balance under dietary or environmental stress. It may also improve feed efficiency and promote consistent appetite and digestive comfort in performance horses.

Mad Barn utilizes Yea-Sacc^® 1026 from Alltech^® as its source of Saccharomyces cerevisiae. This strain has been extensively researched for its effects on digestion, microbial ecology, and nutrient utilization in horses and other livestock species.

Slippery elm (Ulmus rubra) is derived from the inner bark of the red elm tree and is rich in mucilage — a complex polysaccharide that forms a viscous gel when hydrated. This mucilage helps maintain a healthy gastrointestinal lining by providing a physical barrier that supports mucosal hydration and comfort.

By forming a protective layer over the gastric and intestinal mucosa, slippery elm supports normal tissue integrity and helps buffer the effects of acid and dietary stress. Its demulcent properties contribute to digestive comfort and may assist in maintaining regular motility and stool consistency.

Slippery elm is included in Visceral+ to help support gastric and hindgut health in horses by promoting normal mucosal defense and a balanced digestive environment.

Threonine is an essential amino acid and one of the primary limiting amino acids in equine diets, meaning it often limits the rate of protein synthesis when insufficiently supplied. It plays a key role in maintaining normal muscle development, immune function, and digestive health.

Within the gastrointestinal tract, threonine is a critical component of mucin glycoproteins that protect and maintain the gut lining. Adequate threonine intake supports gut integrity, particularly in horses consuming high-grain or low-quality forage diets, or those experiencing digestive stress.

Beyond its role in gut barrier function, threonine contributes to the synthesis of structural proteins, enzymes, and neurotransmitters. It works synergistically with lysine and methionine to optimize amino acid balance, supporting lean tissue development and recovery in growing, performance, or metabolically challenged horses.