Alfalfa does not directly make a horse “hot” in the sense of increasing body temperature, but it can certainly influence a horse’s energy levels and temperament, leading owners to perceive the horse as being “hot” or excitable. This perceived effect is usually related to its high nutrient content, particularly protein and energy, not a direct thermal reaction.
Deciphering the “Hot” Horse Myth
The idea that feeding alfalfa makes a horse “hot” is a long-standing belief in equine circles. This concern often comes up when owners notice changes in their horse’s behavior after introducing or increasing alfalfa in the diet. To get to the truth, we must look closely at what alfalfa actually provides and how those nutrients affect equine physiology and behavior.
What is Alfalfa, Anyway?
Alfalfa (also known as lucerne) is a legume, not a grass. This distinction is key. Legumes are known for being nutrient-dense compared to common grass hays like timothy or orchard grass.
Alfalfa is packed with:
* Higher protein levels.
* More calories (energy).
* More minerals, especially calcium.
Because it is so rich, feeding too much alfalfa without considering the horse’s workload can lead to an excess of available energy. This excess energy is often the source of the behavior issues people label as the Alfalfa effect on horse temperament.
Nutritional Causes of Horse Excitability
A horse’s demeanor—whether calm or spirited—is heavily tied to what it eats. When we talk about a horse being “hot,” we are usually talking about increased alertness, restlessness, or outright spookiness. This is directly linked to energy supply.
Protein vs. Energy
While people often blame the high protein content in alfalfa for making horses hyper, the primary driver of excitability is usually the calories or digestible energy.
The Protein Angle
Yes, alfalfa is high in protein, sometimes containing 18-25% crude protein. For a horse that is not working hard (e.g., a pasture companion or a light trail horse), this high protein intake can lead to unused amino acids. The body converts excess protein into energy, which can contribute to overall energy levels. However, the direct link between protein and hyperactivity is often overstated compared to simple energy intake.
The Energy Connection
Alfalfa generally has more Non-Structural Carbohydrates (NSCs) and Total Digestible Energy (TDE) than grass hay. If a horse consumes more energy than it burns through work or maintenance, that surplus energy must go somewhere.
- The Result: The excess energy manifests as restlessness, more lively movement, or what riders describe as a “fizzy” or “hot” feeling. This is central to the relationship between alfalfa and horse excitability.
A horse on a high-energy diet that isn’t exercising enough will always be more energetic, regardless of whether the energy comes from sweet feed or excess alfalfa hay.
Feeding Alfalfa to Horses and Behavior
When owners notice their horse is suddenly bouncing off the walls after switching to an alfalfa-heavy diet, they often blame the hay itself. However, context matters greatly when feeding alfalfa to horses and behavior.
Assessing the Horse’s Workload
The most crucial factor in feeding management for energetic horses is matching the diet to the demands placed on the horse.
| Horse Type | Typical Daily Energy Needs (Mcal DE) | Alfalfa Suitability | Notes |
|---|---|---|---|
| Companion/Light Walker | 15 – 20 | Low to Moderate | High risk of excess calories if fed freely. |
| Moderate Pleasure Horse | 20 – 25 | Moderate | Can form the base, but needs careful monitoring. |
| Heavy Training/Athlete | 25 – 35+ | High | Excellent source of digestible energy and protein for muscle repair. |
If you feed a horse designed for light work a diet rich in alfalfa, you are essentially feeding it fuel it cannot burn. This fuel becomes pent-up energy, resulting in the signs of a “hot” horse on alfalfa diet: pacing, refusing to stand still, being overly sensitive to aids, or even aggression.
Impact on Temperament
While the nutrient load drives energy, some anecdotal evidence suggests that fluctuations in blood sugar related to NSC levels could influence temperament, though solid scientific backing is limited for hay alone. High-sugar/high-starch feeds are more clearly linked to behavioral spikes. Alfalfa, especially when mature, is usually lower in sugar than rich grass pasture, but its overall caloric density remains high.
If a horse is already prone to being sensitive, adding a rich feed like alfalfa might amplify existing tendencies, making the Alfalfa effect on horse temperament more noticeable.
Can High-Protein Feed Make a Horse “Hot”?
This is a common query. Can high-protein feed make a horse “hot”? Not directly, in the way caffeine affects humans. However, the indirect path is significant.
Protein itself is used for building and repair, not immediate fuel like carbohydrates or fats. If the horse is consuming protein far beyond its daily requirement for maintenance and muscle building, the excess nitrogen must be processed by the liver and kidneys, and the remaining carbon skeleton is used for energy.
Think of it this way: Protein is like lumber for building a house. If you have too much lumber, you can’t use it right away, but you still have a lot of raw material sitting around. If the horse needs the energy from the lumber (protein) because it is lacking in grain or fat sources, it will use it, leading to high energy release.
The issue is complex, as poor-quality, mature alfalfa might contain more indigestible fiber, but excellent, young alfalfa is highly digestible and energy-dense.
Managing ‘Hot’ Horses on Alfalfa
If you suspect alfalfa is contributing to your horse being too spirited, you don’t necessarily need to banish it entirely. Managing ‘hot’ horses on alfalfa involves smart adjustments rather than outright removal.
1. Dilute the Density
The easiest fix is mixing the alfalfa with lower-calorie, higher-fiber grass hay. This maintains the chewing time and gut health benefits of forage while lowering the overall energy intake.
- Example Strategy: Feed 50% grass hay (e.g., Timothy) and 50% alfalfa. This provides the necessary calcium and protein boost without the energy overload for many horses.
2. Control Intake Timing
Free-choice feeding of rich hay can be problematic for easy keepers or energetic horses. Consider using slow-feeders or nets that restrict the amount eaten per hour. This spreads the energy intake over a longer period, potentially stabilizing blood sugar and energy levels.
3. Increase Workload
If the horse is consuming a high-energy diet (including alfalfa) and remains energetic, the most logical solution is to increase the amount of work performed. A horse that has a tough 45-minute fitness session will likely utilize the calories provided by the alfalfa much better than one that only spends an hour walking around the paddock. This addresses the nutritional causes of horse excitability by balancing intake with output.
4. Monitor Overall Diet
Look beyond the hay. Is the horse getting sweet feed, molasses treats, or other high-starch supplements? Sometimes, alfalfa gets the blame when the real culprit is a commercial grain ration that is too rich. Always look at the total diet picture when addressing alfalfa and horse energy levels.
Is Alfalfa Too Rich for Some Horses?
Yes, absolutely. Is alfalfa too rich for some horses? For many horses, especially those prone to obesity, metabolic issues like Equine Metabolic Syndrome (EMS), or laminitis, alfalfa can indeed be too rich if fed freely or in large quantities.
The Calcium Factor
Alfalfa is notably high in calcium. While this is beneficial for growing horses, pregnant mares, and horses in heavy work (which require more calcium for bone density maintenance), it can cause an imbalance if fed to horses receiving high levels of phosphorus from grain without proper balancing. Excess calcium is generally excreted, but extremely high intake can sometimes interfere with magnesium absorption, though this is rare without other dietary deficiencies.
The Energy Density Issue
For the average pleasure horse, the caloric density of alfalfa means that replacing grass hay entirely can quickly lead to weight gain. Weight gain leads to sluggishness in the long run, but initially, the high energy intake before obesity sets in can translate to behavior issues.
Interpreting the Signs: Signs of a “Hot” Horse on Alfalfa Diet
Recognizing when diet is affecting behavior is key. Here are common signs of a “hot” horse on alfalfa diet:
- Increased Movement: Pacing, shifting weight constantly, pawing excessively at the stall door.
- Sensitivity: Overreacting to stimuli (sounds, touch, rider aids).
- Short Attention Span: Difficulty focusing on tasks during training; seeming distracted or “heady.”
- Physical Signs: Sweating more easily or profusely, especially when cooling down after exercise.
- Restlessness at Rest: Inability to settle down after being stalled or tied up.
If you see these signs, and you have recently increased alfalfa or removed another calorie source, the hay is a likely contributor to the high alfalfa and horse energy levels.
The Benefits of Alfalfa: When It’s the Right Choice
It is important not to demonize alfalfa entirely. It offers significant benefits that are essential for certain types of horses.
Muscle Building and Repair
For horses in hard work—racehorses, upper-level eventers, or intensely trained dressage horses—the high quality of protein in alfalfa is invaluable for muscle synthesis and recovery.
Supporting Ulcer Prevention
Alfalfa is more highly buffered than grass hay due to its higher calcium content. This makes it excellent for buffering stomach acid. Horses prone to gastric ulcers often benefit significantly from having alfalfa mixed into their diet, as the chewing action and buffering capacity help maintain a healthy gut pH. This can actually calm a horse whose behavior is being negatively impacted by gastric pain.
Supporting Growth
Young, growing horses need the dense nutrition and high calcium levels found in alfalfa to support rapid skeletal and muscle development.
Comparing Alfalfa to Grass Hays
To put the “hot” debate into perspective, here is a quick comparison of typical nutrient profiles. (Note: Values vary widely based on maturity and conditions).
| Component | Typical Alfalfa Hay | Typical Grass Hay (e.g., Timothy) | Implication for Energy |
|---|---|---|---|
| Crude Protein | 18% – 25% | 7% – 12% | Alfalfa provides significantly more building blocks. |
| Digestible Energy (DE) | Higher (often > 1.0 Mcal/lb) | Lower (often 0.8 – 0.9 Mcal/lb) | Alfalfa contributes more readily usable calories. |
| Calcium | High (0.4% or more) | Low to Moderate | Good for bone support, but must be balanced. |
This table highlights why alfalfa is perceived as providing more fuel, thus impacting alfalfa and horse energy levels.
Final Thoughts on Alfalfa and Excitability
The consensus among equine nutritionists is that alfalfa itself is not inherently a “hot” feed, but its high energy and protein content means it requires careful management.
The problem rarely lies in the alfalfa plant itself, but rather in the mismatch between the horse’s energy needs and the energy density of its ration. If you have a horse that becomes excitable on alfalfa, look at your feeding management for energetic horses:
- Quantify: Measure how much hay is being fed.
- Evaluate Work: Is the horse working hard enough to justify the calories?
- Dilute: Mix with lower-energy grass hay.
- Observe: Track behavior changes against diet changes.
By applying sound nutritional principles, you can harness the great benefits of alfalfa—muscle support, excellent buffering—without suffering the drawbacks of a suddenly opinionated or overly energetic mount.
Frequently Asked Questions (FAQ)
Q1: If I feed my horse a 50/50 mix of grass and alfalfa, will it still get enough calcium?
A: For most adult maintenance or light work horses, a 50/50 mix offers a very good mineral balance, often eliminating the need for many calcium supplements. Horses in heavy work may still need supplemental calcium or a higher ratio of alfalfa to meet peak requirements for bone density. Always consult a veterinarian or equine nutritionist to test your forage and create a precise ration for your horse’s specific needs.
Q2: How quickly does the Alfalfa effect on horse temperament appear after starting the feed?
A: Changes in alfalfa and horse energy levels can sometimes be noticed within a few days if the horse switches suddenly from a very low-energy diet to a high-energy diet. However, significant behavioral shifts related to excess calorie storage (weight gain) take weeks or months to fully develop. Gradual introduction is always recommended to allow the digestive system and temperament to adjust.
Q3: Are there specific types of alfalfa that are more likely to make a horse hot?
A: Yes. Young, leafy, early-cut alfalfa (often labeled “first cut” or “premium”) is usually the most nutrient-dense and thus has the highest potential to contribute to excitability if overfed. Mature, coarser alfalfa (late-cut) is more fibrous and less energy-dense, making it a safer choice for horses prone to gaining weight or becoming too spirited on rich feeds.
Q4: Does soaking alfalfa change its nutritional content enough to affect a horse’s energy levels?
A: Soaking hay primarily reduces dust and, to a minor extent, leaches out water-soluble sugars and minerals. While soaking reduces the dust component (which is beneficial for respiratory health), it does not drastically reduce the energy content (calories derived from fiber and protein). Therefore, soaking alfalfa will not eliminate the perceived “hotness” if the issue is fundamentally caloric excess.