How to Supplement Trace Minerals in Your Horse’s Diet

Trace minerals are essential because they support many of the metabolic, structural, and physiological processes that keep horses healthy, sound, and performing well. Although required in relatively small amounts, trace minerals such as copper, zinc, selenium, iodine, manganese, iron, and cobalt are involved in enzyme activity, immune defense, hoof formation, skin and coat quality, connective tissue development, antioxidant protection, thyroid function, and energy metabolism. Horses can consume enough calories and protein to maintain body condition while still falling short in one or more trace minerals, especially when fed mostly hay or pasture without a properly balanced vitamin and mineral supplement. Over time, these imbalances can affect hoof strength, topline development, coat quality, growth, reproduction, exercise tolerance, and recovery. Because trace minerals interact with one another in the body, the goal is not simply to add more minerals, but to provide them in the correct amounts and ratios based on the total diet.

The essential trace minerals for horses include copper, zinc, selenium, iodine, manganese, iron, and cobalt, and each one plays a distinct role in maintaining health and performance. Copper is needed for connective tissue formation, collagen synthesis, iron metabolism, and healthy bone and cartilage development. Zinc supports hoof and skin integrity, immune function, reproductive health, and normal enzyme activity. Selenium works with vitamin E to protect cells from oxidative damage and is especially important for muscle health and immune function. Iodine is required for normal thyroid hormone production, which influences metabolic rate, growth, and thermoregulation. Manganese contributes to cartilage formation, bone development, and carbohydrate metabolism. Iron is involved in oxygen transport and red blood cell formation, although deficiency is uncommon in horses compared to excess intake. Cobalt is required by hindgut microbes for vitamin B12 synthesis, which supports energy metabolism. Because each trace mineral has a different role and because imbalances between minerals can interfere with absorption and utilization, horses benefit most from a balanced supplement program rather than isolated supplementation unless a specific need has been identified.

The best trace mineral supplement for horses is one that balances the nutrients already provided by the forage and the rest of the diet without adding excess calories, starch, or unnecessary minerals. In practice, this usually means feeding a well-formulated vitamin and mineral supplement or ration balancer that provides copper, zinc, selenium, iodine, and manganese in bioavailable forms and in appropriate ratios. A good product should also account for the fact that many forage-based diets are high in iron and relatively low in copper and zinc, which makes mineral balance more important than simply delivering large amounts of individual nutrients. For many horses, a comprehensive product such as Mad Barn’s Omneity® can help fill common gaps in trace minerals while also supplying key vitamins and amino acids to support overall health. Horses with high-iron forage or metabolic concerns may benefit from a more specialized formula such as AminoTrace^®, which is designed to provide elevated copper and zinc without excess sugar or starch. The best choice always depends on the horse’s forage, workload, body condition, and the rest of the feeding program.

Trace mineralized salt can be part of a feeding program, but it should not be relied on as the main source of trace minerals for most horses. Horses consume salt primarily to meet their sodium and chloride requirements, not to correct deficiencies in copper, zinc, selenium, or other trace minerals. This means intake of trace mineralized salt is highly variable and often too low to provide meaningful amounts of the minerals horses actually need. In many cases, plain loose salt is the better choice alongside a properly balanced vitamin and mineral supplement because it allows sodium intake to be managed separately from trace mineral intake. This approach gives horse owners much greater control over the overall ration and helps ensure that important nutrients are provided consistently and at appropriate levels. Trace mineralized salt may offer some supplemental value, but it should generally be viewed as a secondary source rather than a complete mineral solution.

Trace mineral salt blocks are unlikely to provide enough trace minerals to fully meet a horse’s requirements because horses do not consume them in a consistent or predictable amount. Intake varies based on the individual horse, environmental conditions, access to other salt sources, and whether the horse is stalled or housed in a group. Even when a horse uses a salt block regularly, the amount of copper, zinc, selenium, and other trace minerals consumed is typically too low to balance the diet properly. This is especially true for horses eating forage-based diets that already tend to be low in key trace minerals. Salt blocks are best used to provide free-choice sodium, but they are not a reliable substitute for a measured daily vitamin and mineral supplement. Horses that need dependable trace mineral intake are better served by a product that can be fed at a known rate each day.

Zinc and copper are commonly deficient in horses because many hays, pastures, and unfortified forage-based diets do not provide these minerals in sufficient amounts to meet requirements, especially when compared to the horse’s long-term needs for hoof quality, connective tissue maintenance, immune support, and metabolic function. At the same time, forages and water sources are often relatively high in iron, which can further complicate mineral balance because excess iron may interfere with the absorption and utilization of copper and zinc. These two minerals are also closely linked to one another, meaning the dietary ratio matters as much as the absolute amount provided. Feeding more zinc without enough copper, or vice versa, can create secondary imbalances that affect how effectively the horse uses both nutrients. This is why many equine diets benefit from a supplement that provides copper and zinc together in balanced amounts rather than relying on single-mineral products unless a ration analysis clearly supports that approach.

Forage alone often does not provide enough trace minerals to fully meet a horse’s needs, even when it supplies adequate calories and fiber. The mineral content of hay and pasture varies widely depending on soil conditions, plant species, stage of maturity, fertilization practices, geographic region, and harvest conditions. As a result, two forage sources that look very similar can differ substantially in the amounts of copper, zinc, selenium, iodine, and manganese they provide. Many horses maintained primarily on forage consume diets that are adequate in energy but still low in one or more important trace minerals, particularly copper and zinc. Forage can also contain high levels of iron, which may worsen existing mineral imbalances. Because of this variability, the most accurate way to determine whether forage is meeting the horse’s trace mineral needs is through forage analysis combined with a full ration evaluation. In many cases, adding a well-formulated supplement is necessary to bring the diet into balance.

Trace mineral requirements change according to the horse’s stage of life, growth rate, reproductive status, and workload because these factors affect tissue turnover, metabolic demand, and nutrient utilization. Growing horses need carefully balanced trace minerals to support bone formation, cartilage development, connective tissue strength, and overall growth. Pregnant and lactating mares require adequate copper, zinc, selenium, iodine, and manganese to support fetal development, colostrum quality, milk production, and their own recovery. Performance horses also place greater demands on the body due to training stress, muscle metabolism, tissue repair, and the need for strong antioxidant defenses. Even mature horses at maintenance still require appropriate trace mineral intake to support hoof quality, immunity, and normal metabolic function, but the margin for error becomes smaller in horses that are growing, breeding, competing, or recovering from illness or injury. This is why trace mineral supplementation should be adjusted to the horse’s physiological needs rather than fed at the same level to every horse regardless of circumstance.

Selenium supplementation is safe for horses when total intake from forage, fortified feeds, and supplements is kept within appropriate levels, but it must be managed carefully because selenium has a narrower safety margin than many other minerals. Selenium is essential for antioxidant protection, immune support, thyroid hormone metabolism, and normal muscle function, and deficiency can contribute to poor performance, muscle issues, and impaired immune response. However, excessive selenium intake can be harmful, especially when multiple selenium-containing products are combined without reviewing the full diet. This is why selenium should not be supplemented blindly. A well-formulated vitamin and mineral supplement provides selenium in an amount intended to complement the rest of the diet, but owners should still consider regional forage levels and whether additional selenium is already being supplied through grain, ration balancers, or other supplements. When fed as part of a balanced ration, selenium is both safe and beneficial for most horses.

Trace mineral deficiencies in horses are often difficult to identify based on outward signs alone because the symptoms tend to develop gradually and may overlap with many other nutritional or management problems. Horses that are low in important trace minerals may show poor hoof quality, dull hair coat, slow growth, reduced topline, decreased exercise tolerance, slower recovery, reduced immune resilience, or generally poor performance despite receiving adequate calories. However, these signs are not specific to one mineral deficiency and do not always appear until an imbalance has been present for some time. Bloodwork is useful for evaluating certain nutrients, such as selenium in some cases, but it is not a reliable stand-alone test for most trace mineral status. The best way to assess whether a horse is deficient is to evaluate the full diet, including hay, pasture, water, grain, and supplements, and compare nutrient intake to the horse’s requirements. A forage analysis and ration balancing are usually much more informative than guessing based on appearance alone.

The most important trace minerals for performance horses generally include copper, zinc, selenium, and manganese because these nutrients support the tissues and metabolic systems most affected by exercise. Copper and zinc help maintain connective tissue integrity, hoof quality, skin health, and immune function, all of which are important for horses in consistent work. Selenium is critical for antioxidant protection and normal muscle function, especially when training increases oxidative stress and muscle turnover. Manganese supports cartilage health and enzyme systems involved in energy metabolism. Performance horses may not always need dramatically higher trace mineral intake than horses at maintenance, but they do require a diet that is more consistently balanced because even marginal deficiencies can affect soundness, recovery, and resilience over time. When forage is the foundation of the diet and grain is fed at low levels, a concentrated vitamin and mineral supplement such as Mad Barn’s Omneity® is the most effective way to ensure performance horses receive adequate trace mineral support.

Horses with hoof problems often need closer attention to copper and zinc because these are the trace minerals most closely associated with keratin production, connective tissue quality, and normal hoof horn development. Hoof quality is influenced by the entire diet, not just one nutrient, but low copper and zinc intake is a common finding in horses with weak hoof walls, poor horn quality, slow growth, or recurrent cracking. Selenium may also play a supportive role through its antioxidant functions, and overall diet quality matters because protein, amino acids, vitamins, and major minerals all contribute to hoof health. In horses eating forage that is high in iron and low in copper and zinc, restoring appropriate trace mineral balance can be especially important. If the entire diet needs broad support, a complete product such as Mad Barn’s Omneity® or AminoTrace^® may be appropriate depending on the horse’s metabolic status and forage profile. If the primary issue is a copper and zinc imbalance within an otherwise balanced diet, a targeted product such as Mad Barn’s 3:1 Zinc Copper may make sense.

Trace minerals for metabolic horses should be supplemented in a concentrated, low-calorie form that does not require feeding large amounts of grain or sweetened feeds. Horses with insulin dysregulation, easy-keeper tendencies, or other metabolic concerns still need adequate copper, zinc, selenium, iodine, and manganese, but they often do best on diets that are low in sugar and starch. This makes it especially important to use a product that delivers necessary micronutrients without unnecessary calories, molasses, or fillers. For horses eating high-iron forage, correcting copper and zinc balance can also be an important part of the feeding program. Products such as Mad Barn’s AminoTrace^® are designed for this type of situation by providing concentrated vitamin and trace mineral support suitable for easy keepers and horses with metabolic concerns. As with any horse, the best approach is to evaluate the total diet and match the supplement to the forage and individual needs of the horse.

Growing horses need a well-balanced supply of copper, zinc, manganese, selenium, and iodine because these trace minerals support skeletal development, cartilage formation, connective tissue integrity, immune function, and normal metabolic regulation during periods of rapid growth. Copper and zinc are especially important for developing bone, tendons, and cartilage, while manganese contributes to skeletal development and enzyme activity. Selenium supports antioxidant defenses and muscle health, and iodine is needed for normal thyroid function and growth regulation. Because young horses are still developing structural tissues, deficiencies or imbalances during growth can have more significant long-term consequences than they would in a mature horse. It is also important to remember that growth diets must be balanced overall, with adequate protein, lysine, calcium, phosphorus, and energy, rather than focusing on one trace mineral in isolation. Mad Barn’s Omneity® is a comprehensive vitamin and mineral supplement formulated to help balance forage-based diets, making it a valuable part of supporting the healthy growth and development of foals, weanlings, and yearlings.

Pregnant broodmares need balanced intake of copper, zinc, selenium, iodine, and manganese to support fetal growth, placental function, colostrum quality, immune support, and their own tissue maintenance throughout gestation. These minerals are especially important in late pregnancy, when fetal growth accelerates and nutrient demands rise. Copper and zinc contribute to connective tissue and skeletal development in the fetus, selenium supports antioxidant function and immune health, iodine supports thyroid hormone production and normal metabolic regulation, and manganese contributes to cartilage and bone formation. Broodmares should not rely on free-choice mineral sources or generalized lick tubs to meet these increased needs because intake is too inconsistent. A measured daily supplement is the most reliable way to ensure the diet is properly balanced. For pregnant mares on forage-first diets, Mad Barn’s Omneity® is a strong option for providing comprehensive vitamin and mineral support when the full ration needs to be balanced.

Mineral tubs and licks can be convenient, but they are generally not the best way to provide trace minerals when precision and consistency matter. Intake from these products varies widely from horse to horse based on taste preference, environment, housing, social hierarchy, and access, which makes it difficult to know how much any individual horse is actually consuming. This is particularly problematic when trying to correct known deficiencies or balance a forage-based diet that is low in key trace minerals such as copper and zinc. Some tubs also contain added sugars, molasses, or unnecessary fillers that may not be ideal for easy keepers or metabolic horses. While mineral tubs and licks can offer some supplemental value in certain management settings, they are usually better viewed as a convenience product rather than a dependable nutrition program. Horses that need accurate daily trace mineral intake are better served by a supplement such as Mad Barn’s Omneity®, which is a comprehensive formula designed to balance the majority of forage- and grain-based diets.

The best loose minerals for horses is Mad Barn’s Omneity® Premix because it is professionally formulated to balance the diets of the majority of horses eating hay or pasture-based feeding programs. Rather than supplying isolated trace minerals, Omneity® Premix is designed to provide comprehensive daily nutritional support in a powdered format that helps fill common gaps in forage-based diets. This makes it a practical and reliable choice for supporting hoof quality, coat condition, topline, immune function, metabolic health, and overall performance. Its loose premix form is easy to top-dress on feed or mix with a carrier, and because it is formulated to deliver balanced nutrition without unnecessary calories, it works well for a wide range of horses. At just $0.84 per day with a subscription, Omneity® Premix is also a very affordable option, which is one reason it is so often recommended by nutritionists.