Why I Prioritize Grass in My Horse’s Diet

Have you ever wondered why horses instinctively graze on grass and hay? I used to ask myself the same question until I dove deeper into equine nutrition. Horses are natural foragers, designed through evolution to consume fibrous plants steadily throughout the day. Their digestive system thrives on continuous intake of low-calorie forage, which keeps their hindgut functioning properly. Without consistent access to fiber-rich forage, they can develop health issues like gastric ulcers, colic, and even behavioral problems such as anxiety or chewing on non-food objects.

For my horses, I ensure they have 24/7 access to grass or hay, mimicking their natural feeding patterns. This not only stabilizes their digestion but also prevents boredom and stress, helping them stay mentally and physically healthy.

Understanding Grass

Grass is more than just a pasture covering; it belongs to the Poaceae family, a crucial group of flowering plants that support herbivores like horses, cattle, and wild grazers. I find it fascinating how grasses have evolved to sustain animals while withstanding continuous grazing.

The biological structure of grass consists of:

• Roots: Fibrous root systems that spread horizontally, efficiently absorbing water and nutrients.
• Stems (Culms): Hollow between the nodes, allowing flexibility while growing tall.
• Leaves: Narrow, flat, and elongated, designed to recover quickly after grazing.
• Flowers (Inflorescence): Small, wind-pollinated structures essential for reproduction.

Types of Grass I Feed My Horses

Over time, I’ve learned to choose the best grass varieties based on my horses’ needs and climate conditions:

• Cool-season grasses like meadow grass, orchard grass, timothy grass, and Kentucky bluegrass thrive in cooler climates.

• Warm-season grasses such as Bermuda grass and Bahia grass are better suited to hot, dry conditions.

• Legume forages like alfalfa and clover, while highly nutritious, are not technically grasses and require careful management in equine diets.

The Nutritional Role of Grass

Grass is a powerhouse of nutrients for horses. It provides:

• Fiber: Essential for hindgut fermentation and digestion.

• Carbohydrates: Stored as sugars and starch to fuel energy needs.

• Fats: A small but digestible source of natural fats (about 2-3%).

• Vitamins and Minerals: Rich in vitamins A, E, calcium, and magnesium.

Balancing Grass and Legume Forages

While both grasses and legumes serve as excellent forage, they differ in their nutritional profiles. I ensure my horses get the right balance:

• Grasses (Timothy, orchard, Bermuda) provide high-fiber, moderate-energy forage—ideal for horses with lower energy requirements.

• Legumes (Alfalfa, clover, birdsfoot trefoil) offer high-protein, high-energy forage, making them suitable for performance horses, lactating mares, and growing foals. However, they can be too rich for easy keepers or horses prone to metabolic disorders.

Why I Limit Alfalfa in My Horses’ Diet

Alfalfa and other legumes can be beneficial, but they’re not always ideal for every horse. I use them sparingly due to:

1. Excessive Protein Intake

→Alfalfa contains 15-22% crude protein—far more than my average horse needs.

→ Excess protein requires breakdown by the liver and kidneys, leading to increased urination and potential kidney stress.

→Too much protein can also cause ammonia buildup in the stable, which affects respiratory health.

2. High Calcium Levels

→ Alfalfa’s calcium content (1.2-1.8%) can disrupt the calcium-to-phosphorus ratio, affecting bone health, especially in young horses.

→ Horses prone to enterolithiasis (intestinal stones) are at greater risk when consuming high-calcium diets.

3. Metabolic Risks

→ Alfalfa’s high energy content can contribute to weight gain, insulin resistance, and even laminitis in easy keepers.

4. Digestive Disturbances

→ Some horses experience loose stools when eating legume-rich diets due to lower fiber content compared to grasses.

5. Overeating Risks

→ Horses love the taste of alfalfa, making them more likely to overconsume, which can lead to colic or digestive upset.

When Alfalfa Can Be Beneficial

That said, I do use alfalfa in specific cases:

• Performance Horses: They need extra protein and energy for endurance and recovery.

• Lactating Mares and Growing Foals: Their higher calcium and protein needs make alfalfa a good supplement.

• Hard Keepers: Horses that struggle to maintain weight benefit from alfalfa’s added calories.

How I Use Alfalfa Safely

For my horses, moderation is key. I never rely on alfalfa as the main forage but rather as a supplement. I always:

• Mix it with high-fiber grasses to balance the diet.

• Monitor my horses’ weight and digestion for any signs of metabolic stress or loose stools.

• Adjust portions based on individual needs, ensuring each horse gets optimal nutrition.

Final Thoughts

Grass remains the foundation of my horses’ diet, providing essential fiber, nutrients, and a natural feeding experience. While alfalfa has its benefits, I use it strategically to avoid the risks of excess protein, calcium, and energy. By maintaining a forage-first approach, I ensure my horses stay healthy, happy, and in peak condition.