How turnout, stress and routine affect digestion

We tend to think of equine nutrition as the science of calories, minerals, and macros – choosing the right concentrates, balancing the forage, and tweaking the supplements. But true nutrition goes far beyond what’s in the feed bag or supplement tub. The way a horse is managed – how much turnout they get, how predictable their routine is, how often they experience stress – has a profound impact on whether they can digest, absorb, and benefit from the food we provide.

This article explores the often-overlooked connections between management, stress, behaviour, and digestion, and why good feeding starts with good daily care.

The gut under pressure

The horse’s digestive system evolved to process small, frequent meals over many hours while moving. In the wild, horses graze up to 16 hours a day, and their gastrointestinal tract is in near-constant motion. In contrast, domesticated horses may be confined for much of the day, fed two to three large meals, and exposed to unpredictable or stressful environments—a drastic mismatch with their biology.

This mismatch matters. When a horse experiences stress, the body diverts resources away from digestion and toward the ‘fight or flight’ response. Cortisol levels rise, blood flow to the gut is reduced, gut motility slows, and stomach acid production continues unchecked creating a perfect setting for gastrointestinal upset and ulcer formation.

Turnout

Horses with limited turnout are at significantly higher risk of digestive dysfunction, particularly colic and gastric ulcers. While the exact turnout needs vary by individual, most horses benefit from a minimum of four to six hours of free movement and grazing daily, with more being better.

Turnout supports digestion in several key ways:

• Increased saliva production through near-constant chewing of forage, which helps buffer stomach acid.
• Physical movement enhances gut motility, facilitating the passage of feed through the intestines.
• Mental relaxation reduces stress-related cortisol spikes that can impair digestion.

Even a paddock with sparse grazing can offer important behavioural and physiological benefits if forage is supplemented and movement is encouraged.

The gut-brain axis

A growing body of research in both human and veterinary medicine supports the existence of the gut-brain axis, a two-way communication system between the gastrointestinal tract and the nervous system. In horses, this means that stress doesn’t just affect mood; it alters gut function at the microbial and cellular level.

Stressed horses may show:

• Reduced appetite
• Slower feed transit time
• Disruption to the gut microbiome, leading to dysbiosis
• Increased permeability of the gut wall (‘leaky gut’), which contributes to inflammation and systemic issues

Management strategies that reduce stress, including regular routines, social interaction, soft handling, and sufficient forage, are not luxuries; they’re core to nutritional health.

Feeding forage first

Forage should form the foundation of every horse’s diet, ideally making up 1.5–2% of bodyweight daily in dry matter. But how and when forage is fed can be just as important as the total volume.

Best practices include:

• Ad lib to hay or grazing to mimic natural feeding patterns.
• Use of slow feeders or hay nets to prolong eating time and reduce boredom in stabled horses.
• Avoiding periods without forage, as this increases ulcer risk and stress behaviour.

Routine, predictability, and behavioural wellness

Horses thrive on routine and find safety in predictability. A disorganised, erratic schedule, with irregular turnout, inconsistent feeding times, and sporadic exercise, can create low-grade chronic stress, even in horses that appear outwardly calm.

Signs that routine may be negatively affecting gut health include:

• Wood chewing or cribbing
• Intermittent colic symptoms
• Sudden feed refusals
• Faecal water syndrome
• Unexplained girthiness or sensitivity in grooming

Where possible, horses should be kept on a stable daily rhythm, with feed, turnout, work, and rest occurring at roughly the same time each day. Horses that travel or compete frequently may benefit from supportive gut health strategies – such as gastric buffers or live yeast probiotics – but these should supplement, not replace, good management.

Takeaway

The takeaway is simple: nutrition starts with management.

Even the most expensive feeds and supplements won’t provide full benefit if your horse is chronically stressed, stabled for most of the day, or has inconsistent access to forage. Nutrition doesn’t begin with choosing the right pelleted feed; it begins with giving the horse a life that supports their biological needs.

A balanced ration, thoughtfully constructed, is important. But, without considering factors such as turnout time, social needs, stress levels, routine, and feeding patterns, it’s only part of the picture.