Alfalfa Hay

Alfalfa occupies a unique place in equine nutrition—it's more nutrient-dense than grass hay, richer in protein, and genuinely valuable for many horses, yet it's also misunderstood and sometimes overfed by owners who think "more nutritious" means "better for every horse." Understanding what alfalfa does nutritionally, which horses benefit most from it, and how to feed it appropriately transforms it from a confusing product into a genuinely useful tool for optimizing horse nutrition. You might have heard strong opinions about alfalfa—some people swear by it, others avoid it, and the truth is more nuanced than either extreme position.

Alfalfa is legume hay, fundamentally different from grass hays like timothy or orchard grass in its nutritional profile and how it affects your horse's nutrition. The key difference is that alfalfa is significantly higher in protein, ranging from 15 to 20 percent depending on quality and stage of growth at harvest, compared to grass hay typically at 8 to 12 percent. Alfalfa is also higher in calories and various minerals, particularly calcium, making it nutritionally dense. These characteristics make alfalfa valuable for certain horses and situations, but potentially unnecessary and even problematic for others.

Many owners find alfalfa confusing because it seems expensive and complicated compared to grass hay, yet it's genuinely useful for specific situations. A young, growing horse benefits from the extra protein and minerals. A lactating mare producing milk needs the additional protein and calories alfalfa provides. A performance horse in heavy work needs the caloric density. An aging horse sometimes does better on alfalfa because it's easier to chew and pack with calories. But a calm, middle-aged horse at maintenance with no work? They probably don't need alfalfa and might gain excessive weight from it. Understanding which category your horse falls into makes the decision straightforward.

The role of alfalfa in a balanced nutrition program matters as much as whether you feed it at all. Many people who feed alfalfa feed it as their sole hay source, which creates nutritional imbalances. Alfalfa's high calcium-to-phosphorus ratio—roughly 5 to 1 or higher—can create mineral imbalances when it's the only hay. Feeding alfalfa in combination with grass hay, typically 50/50 or 60/40 alfalfa to grass hay, balances the minerals while providing alfalfa's benefits. This is one of the most practical approaches for horses that benefit from alfalfa's nutrition but don't need alfalfa as their complete forage base.

The cost and availability question often influences whether people choose alfalfa. Quality alfalfa typically costs more per bale than grass hay, making it expensive as a sole hay source for large operations. For many owners, this practical consideration plays a major role in the decision. Understanding what you're actually getting nutritionally for that extra cost helps you decide if it's worth it for your situation. Sometimes it's genuinely valuable; sometimes it's an unnecessary expense that a well-chosen grass hay would address just as well.

The protein in alfalfa is one of its defining characteristics and why it matters for certain horses. Young horses in their growth phase—roughly yearlings through three-year-olds—need protein for tissue development. Growing foals need roughly 14 to 16 percent protein in their diet for proper development, and alfalfa's 15 to 20 percent protein helps achieve this. A growing horse fed only grass hay at 8 to 10 percent protein might have inadequate protein for optimal development. Supplementing grass hay with alfalfa, or feeding alfalfa as part of the forage mix, ensures adequate protein without needing grain supplementation.

Lactating mares have elevated protein needs because milk is protein-rich and they're producing a large volume daily. A mare nursing a foal benefits significantly from alfalfa's protein content, supporting milk production and the mare's own recovery from pregnancy and nursing. A mare that's struggling to maintain condition while nursing might improve dramatically with alfalfa added to her diet. The additional calories and protein support both milk production and the mare's own health.

Performance horses in heavy work benefit from alfalfa's caloric density. A horse working hard might need maximum caloric support from forage, and alfalfa provides more calories per pound than most grass hays. For horses that need to maintain weight on forage without excessive grain, alfalfa can be nutritionally valuable. The energy in alfalfa is more digestible than grass hay, meaning the horse's digestive system can extract and use more calories from it.

The mineral profile of alfalfa, particularly its calcium and potassium content, matters nutritionally. Alfalfa provides excellent calcium, making it useful for horses that might otherwise have calcium deficiency. However, the high calcium-to-phosphorus ratio becomes a potential problem if alfalfa is the only hay source. A diet with calcium-to-phosphorus ratios significantly above 2 to 1 can interfere with phosphorus absorption and ultimately disrupt mineral balance. This is why mixing alfalfa with grass hay or carefully considering supplementation is important when alfalfa is used.

Vitamin content in alfalfa, particularly if it's high-quality and properly stored, is notably higher than in many grass hays. Vitamin A content in fresh alfalfa is substantial, though it decreases with storage time and exposure to light. Some horses with marginal vitamin intake might maintain better vitamin status on alfalfa than on poor-quality grass hay. However, if you're feeding decent-quality grass hay, the vitamin difference might be minimal.

The digestibility of alfalfa is worth understanding. Alfalfa is more readily digestible than many grass hays, meaning the horse's digestive system can break it down and extract nutrients more efficiently. This is advantageous for horses that need maximum nutrition extraction—older horses with reduced digestive capacity, hard keepers needing to maximize calories, or performance horses needing optimal fuel. For easy keepers who don't need maximum nutrient extraction, this can be disadvantageous because they'll get more calories from the same weight of alfalfa than grass hay, potentially leading to unwanted weight gain.

Water and hydration considerations are relevant because alfalfa, being a legume, affects mineral content and thus water requirements. Some horses on alfalfa diets show slightly increased water consumption, which is normally not a problem but worth monitoring. Ensure water access is excellent for any horse on alfalfa to support proper hydration and digestive function.

Determining how much alfalfa to feed depends first on whether you're using it as a sole hay source or mixing it with grass hay. For horses that genuinely benefit from alfalfa—growing horses, lactating mares, or performance horses in heavy work—feeding 100 percent alfalfa as hay is sometimes appropriate, but mixing alfalfa with grass hay is often a more balanced approach. The typical recommendation is 50 percent alfalfa and 50 percent grass hay by weight, though some situations call for different ratios. A pregnant mare might do well on 60 percent grass hay and 40 percent alfalfa. A performance horse might do well on 40 percent grass hay and 60 percent alfalfa. The exact ratio depends on your horse's needs and what other feeds you're providing.

Quantity of hay follows the basic guideline of approximately 2 percent of body weight in forage daily. A 1,000-pound horse needs about 20 pounds of hay daily, whether that's grass hay, alfalfa, or a mixture. If you're feeding 50/50 alfalfa to grass hay mix, that's 10 pounds alfalfa and 10 pounds grass hay daily. The total quantity doesn't change; you're just changing the composition. For horses being fed alfalfa and grain together, remember that alfalfa already provides significant calories, so you might not need as much grain as if you were feeding grass hay alone. Calculating total daily caloric intake and adjusting accordingly prevents overfeeding.

Quality assessment is crucial with alfalfa because poor quality alfalfa isn't worth the expense and might harbor health problems. Good quality alfalfa is bright green, leafy with relatively minimal stem, and free from dust or mustiness. Alfalfa cut at the right stage—typically early bloom—has better nutrition than alfalfa cut later when stems are woody and less digestible. Avoid alfalfa that's dusty, moldy, or discolored, as these indicate improper storage or handling. Quality alfalfa costs more, but it's actually economical because the horse gets more nutrition per bale and you feed less weight.

Storage is essential for preserving alfalfa's value. Unlike grass hay which can sit outside reasonably well, alfalfa benefits significantly from being stored under cover. Rain exposure leaches nutrients and can promote mold growth. Ideal storage is dry, protected from weather, and in good ventilation. If you're storing large quantities, proper hay storage structures are worth the investment.

Introduction and transitions require care with alfalfa, particularly if your horse hasn't been eating it. Start with small amounts mixed with their existing hay and gradually increase the proportion over a week or two. Alfalfa is rich and some horses experience loose stools or digestive upset if switched too quickly. The transition period allows the microbial population in the hindgut to adjust. Once the horse is eating it well, they typically do fine with it as a regular feed.

Feeding frequency with alfalfa should follow the same principles as grass hay—multiple smaller meals are better than one or two large meals. If you have access to feed multiple times daily, doing so improves digestive efficiency. If you're limited to twice-daily feeding, that's workable, but more frequent feeding is better.

Water access becomes particularly important when feeding alfalfa because it's richer and contains more minerals requiring water for proper processing. Ensure your horse has constant access to clean water. In cold climates, heated water can encourage horses to drink more, which is sometimes beneficial when feeding alfalfa.

Growing horses—foals and young stock—are among the clearest cases for feeding alfalfa. A foal nursing from its dam benefits from the dam eating alfalfa because the improved nutrition supports milk quality and production. A weanling or yearling in development phase needs excellent nutrition including adequate protein, and alfalfa provides this effectively. Young horses still in skeletal development—generally through age three or four—benefit from alfalfa's protein and mineral density. For young stock, mixing grass hay with alfalfa or feeding high-quality alfalfa as part of the diet is genuinely beneficial for proper growth and development.

Lactating mares should definitely have alfalfa as part of their diet if it's available and manageable. A mare producing milk loses significant nutrients daily and needs nutritional support. Alfalfa's combination of protein, calories, and minerals directly supports milk production and helps the mare maintain her own condition. Many breeding operations feed lactating mares high-quality alfalfa as their primary hay for this reason.

Pregnant mares benefit from alfalfa in the later stages of pregnancy when the developing foal places significant nutritional demands on the mare. While early pregnancy doesn't necessarily require alfalfa, the final trimester when fetal development accelerates benefits from the additional nutrition alfalfa provides. A pregnant mare in the third trimester eating alfalfa is better positioned for healthy foal delivery and subsequent nursing.

Performance horses in moderate to heavy work benefit from alfalfa's energy density. A horse competing in endurance events, intensively trained for dressage or jumping, or used heavily under saddle might benefit from alfalfa as part of their forage to help maintain condition and energy without excessive grain. The easily digestible calories in alfalfa support athletic performance.

Senior horses with dental problems might actually need alfalfa more than younger horses. Alfalfa, being leafier and less stemmy than many grass hays, is often easier for older horses to chew and process. An older horse with significant dental issues might maintain condition better on alfalfa than attempting to eat stemmy grass hay. The digestibility advantage helps extract maximum calories and nutrition, important for horses with compromised digestive capacity.

Easy keepers generally should not eat alfalfa exclusively because the risk of excess weight and associated metabolic issues is substantial. An easy keeper fed 100 percent alfalfa for prolonged periods is likely to gain excessive weight. If an easy keeper must have alfalfa for some reason—perhaps they're on a shared hay supply with other horses—using it sparingly mixed with grass hay, or using it seasonally, helps manage weight. Some easy keepers do fine on a small amount of alfalfa mixed into grass hay, but this needs careful monitoring.

Horses with a history of metabolic issues, particularly insulin resistance or predisposition to laminitis, need conservative alfalfa use if any. Alfalfa's higher carbohydrate content in some cases makes it less ideal for metabolically-challenged horses. These horses are often better served by quality grass hay supplemented with other nutrients as needed rather than alfalfa. Consult with your veterinarian if your horse has metabolic concerns and you're considering alfalfa.

Mineral imbalances are the most common issue when alfalfa is fed as the sole hay source. The high calcium-to-phosphorus ratio in alfalfa can create problems with mineral absorption. While horses have remarkable ability to regulate calcium and phosphorus, chronically feeding a diet with calcium significantly exceeding phosphorus—which happens with 100 percent alfalfa plus many grain supplements also high in calcium—can eventually create problems. Excess calcium can interfere with absorption of other minerals like magnesium or zinc. The solution is mixing alfalfa with grass hay to balance the minerals or choosing grain supplements carefully to avoid further calcium excess.

Weight gain occurs readily in easy keepers and sometimes in any horse when alfalfa replaces less nutrient-dense forage. An easy keeper switched to alfalfa might gain condition within weeks, potentially triggering metabolic issues or laminitis if predisposed. If weight gain is problematic, either avoid alfalfa or feed very minimal amounts mixed with grass hay rather than alone.

Metabolic issues can be triggered or worsened in susceptible horses by excessive alfalfa feeding. The combination of alfalfa's higher energy density, its mineral profile, and its higher nonstructural carbohydrate content in some cases makes it suboptimal for horses with metabolic syndrome or insulin resistance. These horses often do better on more modest, lower-energy forage sources.

Diarrhea or loose stools sometimes occur with alfalfa, particularly in horses switched too quickly to it. The richness and higher water content can cause loose manure in some individuals. This usually resolves as the digestive system adapts, but a slower transition is often needed. Some horses with chronic diarrhea or sensitive digestive systems might not tolerate alfalfa well regardless of transition period.

Joint swelling or stock up can occasionally occur in horses on high alfalfa diets, though this is not common. Some horses seem to respond better to lower-energy forage. If a horse develops leg swelling or stock up after introducing alfalfa, reducing or eliminating it and monitoring response is reasonable.

Cost-benefit analysis becomes important if alfalfa is expensive in your area and your horse doesn't truly need it. Spending significantly more on alfalfa for a horse that does fine on grass hay is wasteful. Use alfalfa strategically for horses that genuinely benefit rather than as a default feed for all horses.

Determine whether your horse actually needs alfalfa before purchasing it. Growing horses, lactating mares, and hard keepers benefit genuinely. Performance horses in heavy work benefit. Healthy adult horses at maintenance on decent grass hay probably don't need alfalfa. Be honest about your horse's needs rather than assuming alfalfa is universally better.

If you decide to feed alfalfa, mix it with grass hay rather than feeding it exclusively. The 50/50 combination provides alfalfa's benefits while maintaining better mineral balance. You get most of the advantages with fewer potential drawbacks. For horses needing more alfalfa's nutrition, adjust the ratio toward more alfalfa, but rarely go to 100 percent alfalfa unless there's a specific reason.

Check alfalfa quality before purchasing. Bright color, leafy appearance, and lack of dust or mold indicate good quality. Poor quality alfalfa is a waste of money no matter how inexpensive it is. One bale of good quality alfalfa provides more nutrition than multiple bales of poor quality. Ask to see the hay before committing to a load.

Monitor your horse's condition closely when introducing alfalfa. Track weight changes, body condition, and how the horse looks and feels. If weight gain is rapid or problematic, reduce the amount of alfalfa or switch to a grass hay-only diet with supplementation if your horse needs additional nutrition.

Consider your horse's individual metabolic status before feeding alfalfa. If you know your horse is an easy keeper or has metabolic concerns, approach alfalfa cautiously. Talk to your veterinarian if you're unsure whether alfalfa is appropriate.

Budget appropriately for quality alfalfa if you choose to feed it. The cost difference between cheap alfalfa and quality alfalfa might seem significant, but quality hay provides better nutrition and results in better horse health, making it economical in the long run.