The Science Behind our Feeding Calculator

At 4 The Love of Horses, we believe horse owners deserve to understand exactly how their horse’s feeding plan is calculated. Our calculator is built on veterinary science, equine nutrition research, and decades of practical feeding experience.

Let’s break down the science behind each calculation.

📏 Step 1: Estimating Your Horse’s Weight

Accurate weight is the foundation of any feeding plan. If you don’t have access to a livestock scale, our calculator uses the industry-standard weight tape formula:

Where:

• Girth = Heart girth measurement (around the widest part of the chest, just behind the front legs)
• Length = Body length (from point of shoulder to point of buttock)

Weight Tape Accuracy Tips

• Measure on level ground with your horse standing square
• Ensure the tape is snug but not tight
• Take measurements at the same time of day
• For best accuracy, take three measurements and use the average

🌾 Step 2: Calculating Forage Requirements

Forage (hay, haylage, or grass) should form the bulk of every horse’s diet. Our calculator determines forage needs based on dry matter intake, which research shows should be:

Workload	Daily Dry Matter (%)
Light work	2.0% of body weight
Moderate work	2.1% of body weight
Heavy work	2.2% of body weight
Very heavy work	2.3% of body weight

Adjustments for Individual Circumstances

The base percentage is then adjusted for your horse’s specific situation:

• Good turnout + lush pasture: Reduce by 0.2-0.3% (they’re getting nutrition from grazing)
• Limited turnout + poor pasture: Increase by 0.2% (more reliance on provided forage)
• Stabled most of the time: Increase slightly to maintain gut health

Converting Dry Matter to “As-Fed” Weight

Different forages have different moisture content:

• Hay: ~90% dry matter (multiply DM by 1.0)
• Haylage: ~70% dry matter (multiply DM by 1.3)
• Fresh grass: ~20-25% dry matter (horses graze significantly more by weight)

🌾 Step 3: Determining Concentrate Needs

Concentrates (grain, pellets, mixes) provide additional energy and nutrients when forage alone isn’t enough. The amount depends primarily on workload:

Workload	Concentrate Range	Typical Scenarios
Light	0-0.5% body weight	Pleasure riding, light hacking
Moderate	0.2-0.8% body weight	Regular schooling, competitions
Heavy	0.4-1.2% body weight	Advanced training, eventing
Very Heavy	0.6-1.5% body weight	Racing, elite competition

Special Considerations

The calculator adjusts concentrate recommendations for:

• Young horses (0-5 years): +15% for growth and development
• Senior horses (16+ years): May need senior-specific feeds with adjusted protein and easily digestible ingredients
• Good pasture + extensive turnout: Reduces concentrate needs significantly
• Poor pasture + limited turnout: +10% to maintain body condition

🎯 Why These Numbers Matter

Preventing Common Health Issues

Underfeeding forage can lead to:

• Gastric ulcers (horses produce stomach acid continuously)
• Stereotypies (cribbing, weaving, wood chewing)
• Weight loss and poor body condition

Overfeeding concentrates can cause:

• Colic and digestive upset
• Laminitis in susceptible horses
• Behavioral issues (“hot” or nervous behavior)
• Developmental orthopedic disease in young horses

The Forage-First Philosophy

Our calculator always prioritizes quality forage as the foundation of equine nutrition because:

1. Digestive health: The horse’s hindgut evolved to ferment fiber
2. Behavioral welfare: Horses naturally graze 16-18 hours per day
3. Nutritional completeness: Good forage provides most vitamins and minerals
4. Cost-effectiveness: Forage is typically more economical than concentrates

📚 Scientific References

Our calculations are based on research and guidelines from:

• National Research Council (NRC) – Nutrient Requirements of Horses, 6th Edition
• Equine nutrition research from universities including Cornell, Kentucky, and Edinburgh
• British Horse Society feeding guidelines
• Practical feeding experience with thousands of horses across all disciplines

🔄 Monitoring and Adjusting

A feeding plan is never “set and forget.” Monitor your horse regularly:

• Body condition scoring every 2-4 weeks
• Weight tracking monthly (using tape or scale)
• Energy levels during work
• Manure consistency and frequency
• Coat condition and overall appearance

Adjust feeding based on these observations. Weight changes take time – allow 2-3 weeks before making significant adjustments.

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Disclaimer: This calculator provides general feeding guidelines based on scientific research and industry best practices. It does not replace professional veterinary or equine nutritionist advice. Always consult with your veterinarian, especially for horses with health conditions or special dietary needs.