Does Protein Make Horses Hot?
No — Protein Doesn’t Make Horses Excitable. Here’s What Really Influences Energy Levels
It’s one of the most common beliefs in the horse world: “I don’t want to feed a high-protein feed because it will make my horse hot.”
It’s a belief that has persisted for years—but it’s a myth.
Protein does not make horses excitable. In fact, protein plays a completely different role in your horse’s diet, and feeding too little can sometimes do more harm than good. It is in fact a poor source of energy compared to carbohydrates, oil or fibre. Its primary role is in building and repairing muscle, supporting topline, and maintaining healthy body tissues.
If a horse becomes “hot,” the cause is much more likely to be the type of energy in the diet—particularly high levels of starch and sugar—rather than the protein content.
Why Do People Think Protein Makes Horses Hot?
Many horse owners assume that if a feed contains a higher level of protein, it will make their horse more energetic or difficult to handle.
The reality is that protein is not what drives a horse’s behaviour or energy levels.
What Actually Provides Horses with Energy?
The energy your horse uses for work, movement and performance comes from:
- Fibre
- Oil
- Starch
- Sugar
However, not all energy sources behave in the same way.
Fast-Release Energy
Feeds high in starch and sugar, particularly cereal-based feeds, provide quick-release energy.
Some horses may become more reactive or excitable when fed high levels of these ingredients.
Slow-Release Energy
Fibre and oil provide a steadier source of energy, helping to support performance without the peaks and troughs often associated with high-starch diets.
This is why many owners of sharp or sensitive horses choose fibre and oil-based feeds.
What Does Protein Actually Do?
Protein is essential for growth, repair and maintenance throughout the body.
Your horse uses protein to support:
- Muscle development and topline
- Tissue repair and recovery
- Healthy skin, coat and hooves
- Immune system function
- Everyday maintenance of body tissues
Rather than providing “sparkle”, protein helps your horse build and maintain a strong, healthy body.
Why Cutting Protein Can Be a Mistake rather than Help
If owners are worried about excitability, they sometimes choose feeds with lower protein levels.
The problem is that reducing protein unnecessarily can affect:
❌ Muscle maintenance
❌ Topline development
❌ Recovery after exercise
❌ Overall condition and performance
In some cases, horses that are struggling to build muscle or maintain topline may actually benefit from more high-quality protein, not less.
Protein Quality Matters More Than Protein Percentage
When it comes to protein, it’s not just about the percentage listed on the bag.
The quality of the protein is equally important.
Horses need essential amino acids, such as lysine and methionine, which act as the building blocks for muscle and tissue development.
A feed containing the right amino acids can often support your horse more effectively than simply focusing on a crude protein percentage.
If My Horse Is Sharp, What Should I Look At Instead?
If your horse is prone to excitability, it may be more helpful to focus on:
✅ The starch and sugar levels in the diet
✅ The overall calorie intake
✅ Whether energy is coming from cereals or from fibre and oil
✅ Workload, fitness and management factors
In many cases, choosing a low-starch, fibre-based feed is a more effective strategy than reducing protein levels.
Choosing a Low-Starch Feed for Controlled Energy
If your horse is sharp or excitable, reducing protein isn’t the answer. Instead, look for a low-starch, high-fibre feed that provides slow-release energy. These diets help support calm, manageable performance while still supplying the high-quality protein needed for muscle development, recovery and overall health.
The Connolly’s RED MILLS Horse Care Range is formulated to provide controlled energy through carefully balanced nutrition and lower starch levels.
These feeds are designed to support:
- Calm, manageable energy
- Digestive health
- Condition and performance
- Horses prone to digestive sensitivities or gastric ulcers
By focusing on fibre and controlled starch levels, they can help provide sustained energy without relying on high cereal inclusion rates.
The Bottom Line: Protein Doesn’t Make Horses Hot but High Sugar and Starch do!
If you’re worried about your horse becoming “hot”, don’t blame the protein.
DONT’s
❌ Protein does not cause excitability
❌ Lower protein does not necessarily mean a calmer horse
DO’s
✅ Protein supports muscle, recovery and overall health
✅ Starch and sugar are much more likely to influence behaviour and energy spikes
✅ Choosing the right type of energy source is often more important than reducing protein
Remember: protein supports the horse’s body — it doesn’t power their behaviour!

