Is Alfalfa Hay Right for Your Horse?

Last updated: May 7, 2025

By: Miles HenryFact Checked

Alfalfa: The ‘Queen of Forages’ or a dietary dilemma? As horse owners grapple with conflicting advice, understanding alfalfa’s true place in equine nutrition is crucial. As a long-time horse owner, I’ve seen firsthand both its remarkable benefits and the importance of balanced application. For instance, managing one mare’s digestive sensitivities required carefully balancing her alfalfa intake with Bermuda hay – a practical lesson learned over years in the barn.

This guide offers a comprehensive look at alfalfa hay for horses, blending scientific understanding with decades of firsthand experience in equine nutrition and training. We’ll explore its unique qualities, benefits (particularly for performance horses), potential concerns, practical solutions, and clear feeding guidelines. My aim is to provide you with the knowledge to confidently use alfalfa to optimize your horses’ health and performance.

What is Alfalfa Hay?

Alfalfa hay is one of the most nutritionally dense forages available to horse owners. Understanding its origins, botanical features, and how it compares to grass hays helps determine when and how to feed it effectively.

Origins and Botanical Characteristics

Alfalfa (Medicago sativa) is a perennial legume that originated in South Central Asia and is now cultivated worldwide. Unlike grass hays, alfalfa’s deep root system allows it to access nutrients from deeper soil layers, contributing to its rich mineral content. Characterized by its trifoliate leaves and purple flowers, alfalfa is typically harvested in multiple cuttings throughout the growing season. Earlier cuttings generally have a higher leaf-to-stem ratio, resulting in greater nutrient density compared to later, more stemmy cuttings.

Key Differences from Grass Hays

Alfalfa hay stands apart from common grass hays like timothy and Bermuda in several key ways:

• Color & Texture: It typically has a rich green color and a leafy texture with finer stems. Grass hays tend to be lighter in color with coarser, more prominent stems.
• Palatability: Horses often find alfalfa more palatable due to its soft texture and slightly sweet taste.
• Nutritional Content:
  • Crude Protein: Alfalfa boasts a significantly higher crude protein content, ranging from 15–22% on a dry matter basis, compared to the 7–12% found in most grass hays.
  • Calcium: Alfalfa is a rich source of calcium, typically containing 1.0–1.5% on a dry matter basis, while grass hays generally range from 0.2–0.8%.
  • Digestible Energy: Alfalfa generally provides a higher level of digestible energy compared to many grass hays.
  • Fiber: Earlier cuttings of alfalfa tend to have lower levels of structural fiber (ADF and NDF) compared to grass hays and later alfalfa cuttings.
  • Vitamins: Alfalfa is a good source of fat-soluble vitamins A and K, and its Vitamin D content varies depending on sun curing.

In my own feeding program, I’ve found that understanding the nutritional differences between types of hay is essential to choosing the right mix for each horse’s needs. If you’re looking to make informed decisions based on your hay’s actual nutrient content, I highly recommend reviewing the University of Minnesota Extension’s guide on Understanding Your Hay Analysis. For a deeper dive into equine nutrition, including specific requirements by age, workload, and physiological status, the National Research Council’s Nutrient Requirements of Horses is an authoritative resource I regularly reference.

Why I Feed Alfalfa Hay: Nutritional Benefits for Horses

Alfalfa’s nutritional profile isn’t just impressive on paper—it consistently delivers results in real-world performance, health, and recovery. In my years of training Thoroughbreds, I’ve come to rely on alfalfa hay as a key component of my feeding program because of how it supports everything from stamina to appetite. Here’s why it earns a place in my barn.

Performance Benefits

In my experience training racehorses, alfalfa plays a critical role in muscle development and recovery. Its high crude protein content—typically 15–22% on a dry matter basis—is rich in essential amino acids that help repair and rebuild muscle tissue after intense workouts. I’ve observed that after a hard gallop or speed work, horses on an alfalfa-based diet recover faster and maintain better topline condition over time. This isn’t just about energy; it’s about giving them the building blocks for sustained strength and endurance.

For more on the importance of hay type and quality in an athletic horse’s diet, see Feeding Horses Hay: How Much, What Kind, and Why It Matters.

Weight Gain & Energy

I once took in a Thoroughbred off the track who struggled to maintain weight, no matter how much grass hay or grain he was given. Adding alfalfa to his forage mix—with its higher digestible energy compared to most grass hays—made a noticeable difference. Within a few weeks, he began to fill out and develop healthier muscle tone, all while staying calm and focused in training. If you’re dealing with a hard keeper, alfalfa may be a game-changer thanks to its energy density and palatability.

Here are more practical tips for feeding skinny horses.

For Picky Eaters

Alfalfa’s palatability is unmatched in my barn. I’ve had horses refuse perfectly good timothy or Bermuda hay, only to dive into a flake of alfalfa with enthusiasm. Its soft texture and slightly sweet taste make it especially useful during stressful periods, post-transport, or recovery from illness, anytime appetite might be suppressed. In situations where maintaining intake is critical, alfalfa almost always gets the job done.

Risks of Alfalfa Hay and How I Manage Them

While alfalfa offers significant benefits, it’s not the right fit for every horse. Over the years, I’ve learned to recognize and manage certain risks associated with feeding this rich forage—especially when it comes to digestive sensitivity, mineral balance, and specific health conditions.

Digestive Sensitivity

One of my mares can’t handle straight alfalfa—it causes loose manure and mild discomfort. But when I mix it 50/50 with Bermuda hay, she thrives. This is a good reminder that some horses are more sensitive to rich forages. If you notice changes in manure consistency, energy levels, or attitude, reduce alfalfa gradually and observe. Every horse’s digestive system is different, and monitoring is key.
Learn more about understanding equine digestion and how horses process feed.

Calcium-Phosphorus Imbalance

Alfalfa is high in calcium, which can interfere with phosphorus absorption. When calcium levels are too high, they may bind with phosphorus in the gut, reducing how much is available for the horse to use. I address this by:

• Mixing alfalfa with grass hay to dilute calcium levels.
• Using ration balancers or performance-focused feeds that supply more phosphorus.
• Occasionally adding phosphorus-rich feeds like oats or wheat bran (sparingly, and always under veterinary guidance).

Excess Protein

There’s a persistent myth that high-protein hay damages the kidneys. In healthy horses with access to plenty of water, this isn’t a concern. Still, I manage protein intake carefully—especially for horses not in active work. Too much protein beyond what the body needs can increase nitrogen waste, leading to more urination and water loss.
Explore more in this guide to protein content in hay and performance horses.

Other Concerns

• Blister Beetles: A serious concern in certain regions, especially the southern U.S. I always source alfalfa carefully and avoid hay from areas where blister beetles are prevalent.
• Dust and Mold: Alfalfa can be dusty if not stored properly. I inspect every bale and soak hay when needed, particularly for horses with respiratory sensitivity.
• Potassium Levels (HYPP): Alfalfa is high in potassium, which can be problematic for horses with HYPP. For these cases, I avoid it altogether or use alternatives under veterinary supervision.

How Much Alfalfa to Feed Horses: Guidelines That Work

Feeding alfalfa successfully depends on matching its nutritional density to your horse’s specific needs. Over the years, I’ve developed a few go-to strategies that have worked well across my barn, but like all feeding plans, they require ongoing observation and adjustment.

Gradual Introduction

Start slowly over 7–10 days. Sudden changes in forage can lead to colic as the horse’s digestive system struggles to adapt. I always introduce alfalfa in small amounts and gradually increase while monitoring manure consistency and overall demeanor.

Amounts by Horse Type (Based on My Experience):

• Performance Horses (40–60% alfalfa): This higher percentage helps meet their increased energy and protein demands for muscle development, stamina, and recovery.
• Underweight Horses (up to 75% alfalfa): In certain cases, the higher calorie density and protein content can aid in healthy weight gain. Always monitor digestive response and body condition.
• Maintenance Horses (20–30% alfalfa): A moderate amount can provide supplemental protein and calcium without adding unnecessary calories for horses in light work or at rest.
• Sensitive or Digestively Challenged Horses (50/50 mix with grass hay): Mixing alfalfa with timothy or Bermuda can reduce richness and improve tolerance. I’ve had good results with this approach for horses prone to soft stool or mild discomfort. Always observe carefully for changes.

These are general benchmarks from my program, not hard rules. A hay analysis gives you the exact nutrient values you need to fine-tune the ratio for your horse’s unique condition, workload, and metabolism.

Forms of Alfalfa

• Bales: Most cost-effective and widely available, but variability can occur between cuttings. Always inspect for mold, dust, and leafiness. Earlier cuttings tend to offer better nutrition.
• Pellets or Cubes: Great for older horses, those with dental issues, or situations where soaking is needed. I feed soaked cubes daily to one of my seniors with great success. These also offer consistent quality and reduce waste. Learn more in my guide to hay cubes and pellets for horses.

Monitoring Horses on Alfalfa Hay: What to Watch For

Every horse is different, and their response to alfalfa can vary significantly based on metabolism, workload, and overall health. That’s why consistent, hands-on monitoring is a core part of my feeding approach. Over the years, I’ve learned that even small signs, like a change in manure or appetite, can indicate that adjustments are needed. Here’s what I track regularly to ensure each horse is thriving on alfalfa:

• Manure consistency: Loose or overly dry manure can signal digestive upset or that the hay is too rich for the horse’s system. When I notice this, I’ll reduce the alfalfa or blend it with a lower-calorie grass hay.
• Body condition score (BCS): Whether the goal is weight gain, maintenance, or supporting high performance, tracking body condition helps me tailor the forage mix appropriately.
• Energy levels and appetite: If a horse suddenly becomes “hot,” lethargic, or starts refusing feed, I take it as a cue to reassess their diet. Sometimes a slight reduction in alfalfa—or adjusting other components—makes all the difference.

When feeding larger amounts of alfalfa, a hay analysis becomes essential. It allows you to balance protein, calcium, fiber, and energy intake with precision. Learn how to interpret a hay analysis.

For a more technical breakdown of why this kind of monitoring matters, I highly recommend Dr. Anne Rodiek’s paper, Hay for Horses: Alfalfa or Grass? presented at the UC Davis Alfalfa Symposium. She outlines how alfalfa’s nutrient density—particularly its high protein and calcium levels—can benefit certain horses but exceed the needs of others, potentially causing imbalances if not properly managed. Her research reinforces why regular observation and ration adjustment are crucial for long-term success.

Frequently Asked Questions About Alfalfa Hay for Horses

Still have questions about feeding alfalfa? You’re not alone—here are answers to the most common concerns I hear from fellow horse owners.

Conclusion: Experience + Science = Smarter Feeding

Alfalfa hay can be one of the most valuable tools in a horse owner’s feeding program—when used with knowledge and care. From my Thoroughbreds in race training to my senior gelding on soaked cubes, I’ve seen its benefits firsthand: stronger muscle tone, improved recovery, better weight maintenance. But I’ve also had to tweak, balance, and rethink my approach for each horse. That’s the heart of good horsemanship—listening, learning, and adjusting along the way.

The bottom line? Use the science we’ve explored as your foundation. Then watch your horse closely, respond to their unique needs, and never assume a one-size-fits-all answer. When experience and evidence work together, you’ll find the right balance—and your horse will show you the results.

What About You?

Have you used alfalfa hay in your feeding program? What have you found helpful—or challenging? Share your experiences, tips, or questions in the comments below. Your insight could help another horse owner make a better decision.

Below is a YouTube video discussing the benefits of alfalfa hay.