The Importance of Feeding Forage Before Grain for Equine Digestive Health

A horse's digestive system has been meticulously designed over millions of years of evolution for a specific purpose: to process forage continuously throughout the day. In our modern management systems, we've often prioritised convenience over biology, sometimes with unintended and serious consequences for our horses. One of the simplest yet most effective practices for maintaining gastric health in horses is feeding forage before grain. This article explores the scientific rationale behind this feeding sequence and offers practical guidance for horse owners seeking to optimise their horses' digestive health.

Understanding the Unique Equine Digestive System

Unlike many other mammals, horses possess what's known as a "trickle-feed" digestive system. This specialised system evolved to process small amounts of fibrous plant material continuously over 16-18 hours daily. The horse is classified as a hindgut fermenter with a relatively small stomach that comprises only about 10% of the entire digestive tract.

Continuous Acid Production

One of the most important aspects of equine digestion that differs from humans is that horses produce stomach acid continuously, whether food is present or not. This evolutionary adaptation makes perfect sense for an animal designed to be eating almost constantly throughout the day. In natural conditions, the constant intake of forage helps buffer this acid production. A horse at pasture may take more than 40,000 chews per day, producing up to 36 litres of saliva that contains natural bicarbonate buffers.

When a horse has an empty stomach, hydrochloric acid can splash onto the unprotected upper portion of the stomach (the non-glandular region), creating the perfect conditions for gastric ulcers to develop. Research from the American Association of Equine Practitioners suggests that up to 90% of performance horses and 60% of pleasure horses suffer from gastric ulcers at some point in their lives.

The Two-Section Stomach

The horse's stomach is divided into two distinct regions:

1. The non-glandular region (upper stomach) - This section has limited protection against acid and is where most gastric ulcers form. It's covered by squamous epithelium, similar to the tissue in the esophagus, with minimal mucus protection.

2. The glandular region (lower stomach) - This section secretes the stomach acid but is protected by thick mucus and other protective substances. Ulcers are less common here but can occur in severe cases.

This unique dual structure makes proper feeding sequence even more important, as the protective mechanisms are unequally distributed throughout the stomach.

The Protective Power of Forage

Forage (hay, pasture, chaff) creates what equine nutritionists refer to as a "protective fibrous mat" in the stomach. This mat serves multiple critical functions:

• Physical barrier: Creates a floating fibrous layer that physically prevents acid from splashing onto the vulnerable non-glandular region
• Acid absorption: Acts like a sponge to absorb and distribute stomach acid throughout the ingesta
• Saliva stimulation: Promotes extensive chewing, which can produce up to three times more saliva than grain consumption
• Buffering capacity: The combination of saliva and the physical properties of forage maintain a more stable pH in the stomach
• Gut motility: Supports healthy peristalsis throughout the entire digestive tract
• Microbial balance: Feeds the beneficial bacteria in the hindgut that help prevent digestive disturbances

When forage is present in the stomach before grain arrives, it establishes this protective environment, significantly reducing ulcer risk and supporting overall digestive function.

The Science Behind Grain's Digestive Impact

Concentrated feeds like grains and commercial pellets fulfill important nutritional needs for many horses, particularly those in work or with special requirements. However, they interact with the digestive system very differently than forage:

Reduced Chewing Time

Research from the University of Minnesota demonstrated that horses chew 3-4 times longer when consuming hay compared to an equivalent weight of grain. Longer chewing time means:

• More saliva production (up to 3 times more than with grain)
• Slower consumption rate, preventing rapid influx of carbohydrates
• More natural muscular activity in the digestive tract
• Greater mental satisfaction and reduced stereotypical behaviors

Altered Fermentation Patterns

When grain enters the stomach and intestines, it undergoes fermentation that produces volatile fatty acids (VFAs) and lactic acid at higher concentrations than forage digestion. A 2018 study in the Journal of Animal Science found that:

• Grain fermentation can significantly lower cecal pH 
• This acidic environment damages beneficial bacteria in the hindgut
• Disrupted microbial populations can lead to endotoxin release
• These changes increase the risk of colic and laminitis

Rapid Gastric Emptying

Grains and processed feeds typically leave the stomach more quickly than fibrous forage. This rapid transit can:

• Create "waves" of acid production in response to the concentrated nutrients
• Lead to gaps in the protective feed mat
• Cause unstable blood glucose levels
• Increase the risk of behavioral issues related to digestive discomfort

The Evidence-Based Case for Forage First

Multiple scientific studies have confirmed that feeding order significantly impacts gastric health:

A landmark study published in the Equine Veterinary Journal found that horses fed grain before forage showed a 67% higher incidence of gastric inflammation compared to those fed forage first.

Another clinical trial involving performance horses demonstrated that ulcer healing rates improved by 45% when feeding protocols prioritized forage before concentrates, even without changing medication protocols.

Misconceptions About Feeding Order

Despite the scientific evidence, several misconceptions persist about equine feeding practices:

Myth: Grain should be fed first because it provides quick energy. Reality: The horse's energy system relies primarily on slow-release energy from fibre fermentation. Even during intense exercise, forage provides critical baseline energy.

Myth: Feeding hay first will "block" nutrients from grain. Reality: Nutrient absorption occurs primarily in the small intestine, not the stomach. Forage actually helps regulate nutrient uptake for more stable energy levels.

Myth: Feeding order only matters for horses with ulcers. Reality: Prevention is more effective than treatment. All horses benefit from digestive practices that respect their natural physiology.

Practical Implementation Strategies

Adopting a forage-first approach is straightforward but requires intentional management:

For Stabled Horses:

1. Provide small portions of hay (0.5-1 kg) at least 30 minutes before any grain meals
2. Use slow-feeders to extend forage consumption time between scheduled meals
3. Consider dividing the daily hay ration into at least 3-4 portions
   

For Horses on Partial Turnout:

1. Schedule turnout to coincide with feeding times when possible
2. For horses with limited grazing time, provide hay before turnout onto lush pasture
3. Consider implementing grazing muzzles that allow continuous forage intake while limiting quantity

For Performance Horses:

1. When traveling, bring familiar hay from home to maintain dietary consistency
2. At competitions, ensure hay is available before warm-up and between classes
3. Consider adding lucerne to the pre-competition diet, as its higher calcium content provides additional buffering capacity
4. Use pre-soaked beet pulp or similar lupin fibre cubes as an additional fibre source when hay availability is limited

For Horses Requiring Significant Grain:

1. Split grain into multiple small meals (never exceeding 2 kg per feeding)
2. Add chaff, soaked beet pulp, or chopped hay to grain meals to increase chewing time
3. Consider using digestive supplements with proven efficacy
4. Monitor body condition and adjust ratios accordingly

Monitoring Digestive Health Success

Measuring the success of your forage-first approach can be done through several indicators:

• Behavioral changes: Decreased cribbing, wood chewing, or weaving
• Physical signs: Healthier weight maintenance, improved coat condition, reduced incidence of colic
• Performance metrics: More consistent energy levels, improved recovery after exercise
• Veterinary assessments: Lower scores on gastroscopic examinations, reduced inflammation markers in blood work

For horses with suspected or confirmed ulcers, work with an equine veterinarian to establish an appropriate treatment program alongside management changes.

Beyond Feeding Order: A Comprehensive Approach to Equine Digestive Health

While feeding sequence is important, digestive health requires a holistic approach:

Stress Management

Stress triggers cortisol release, which can exacerbate gastric acid production. Reduce stress by:

• Providing regular turnout and social interaction
• Maintaining consistent routines
• Using positive reinforcement training methods
• Creating periods of unstructured time in the horse's schedule

Water Availability

Adequate hydration is essential for proper digestion. Ensure:

• Clean, fresh water is available at all times
• Water temperature is moderate (horses drink more readily)
• Water sources are available before, during, and after exercise
• Salt supplementation encourages drinking and assists electrolyte balance

Environmental Enrichment

Boredom and frustration contribute to both stress and digestive issues. Consider:

• Varied forage sources (different types of hay, safe browsing options)
• Appropriate social groupings that allow safe interaction
• Cognitive challenges that mimic natural foraging behaviors
• Regular but varied exercise routines

Medication Considerations

Some common equine medications can impact digestive health:

• Non-steroidal anti-inflammatory drugs (NSAIDs) can increase ulcer risk
• Certain antibiotics may disrupt hindgut bacterial populations
• Corticosteroids can affect gastric mucosa integrity

Always discuss digestive health implications when medications are prescribed.

Conclusion

The simple practice of feeding forage before grain honors the horse's natural digestive physiology and represents one of the most impactful management changes horse owners can implement. While it may require adjusting established barn routines, the benefits to equine health and performance are substantial and well-documented.

By prioritising forage-first feeding, monitoring outcomes, and adopting complementary management practices, horse owners can significantly reduce the risk of gastric ulcers and support optimal digestive function. In our quest to provide the best care for our horses, sometimes the most effective solutions are those that align most closely with the horse's evolutionary design.

Remember: in the horse's world, fibre comes first—not just in nutritional importance but in optimal feeding sequence as well. Your horse's stomach will thank you for respecting this fundamental principle of equine digestive health.