Horses are natural “trickle-feeders,” evolved to graze for 12 to 20 hours each day. This near-continuous intake supports digestive health, stabilizes gastric conditions, and aligns with their behavioural instincts. However, modern management practices, particularly scheduled feeding while being stalled for most of the day, as is often the case with competition horses, can disrupt these natural patterns.
Recent research combining controlled feeding trials with behavioural monitoring technologies offers deeper insight into how diet composition, forage availability, and circadian rhythms interact to shape equine feeding behaviour.
A 2025 study by Fowler et al investigated how different concentrate feeds and hay availability influence feeding behaviour and satiety in stalled horses. Eight Thoroughbred geldings were assigned to four dietary treatments: high-starch (HS), low-starch (LS), high-fiber pellets (FP), and a ration balancer (RB). Each feeding period included phases of free-choice hay access followed by restricted hay intake (1.5% of body weight). Researchers monitored how quickly horses consumed their concentrate meals, how much hay they ate, and how soon they resumed forage intake after eating grain.
The findings revealed clear differences in feeding behaviour depending on diet composition. Horses fed the ration balancer consumed the most hay (2.1% BW), while those on high-starch and low-starch concentrates consumed the least (1.8% BW). Interestingly, meal duration also varied: horses took the longest to consume low-starch feeds and the least time with ration balancers. These differences likely reflect physical and nutritional properties of the feeds, such as fibre content, energy density, and chewing requirements.
Hay restriction had a notable impact on behaviour. When forage was limited, horses began eating hay sooner after finishing their grain meals across all diet types. Additionally, horses fed high-starch diets took longer to finish their meals under hay restriction, suggesting that forage availability influences not only hunger, but also how concentrates are consumed. Even though high-fibre pellets were fed in smaller quantities, they produced satiety responses similar to larger, energy-dense meals, highlighting the importance of fibre in regulating intake behaviour.
These results underscore the complexity of satiety in horses, which is influenced by both physical factors such as chewing time and stomach fill, and post-ingestive nutrient feedback. Fibre-rich feeds may promote a sense of fullness comparable to high-calorie diets, potentially offering a strategy to support digestive health while managing energy intake.
Chewing Halter Study
Studies using innovative chewing halter technology have shed light on how horses distribute their intake over time, particularly overnight. Developed by Itin + Hoch, these halters measure chewing duration, frequency, and intensity.
One study conducted by Kentucky Equine Research examined how horses consumed timothy hay overnight when provided with either one or two hay nets. The goal was to determine whether multiple feeding points would encourage more natural grazing patterns, increase movement, and extend total chewing time. Surprisingly, the number of hay nets had less influence than the time of night.
Chewing activity followed a consistent circadian rhythm regardless of feeding setup. Intake peaked in the early evening (6:00 p.m. to 10:00 p.m.), declined gradually overnight, and reached its lowest point between approximately 9:00 p.m. and 5:00 a.m. A modest increase in feeding occurred again before morning. This pattern suggests that horses are strongly guided by internal biological clocks rather than external feeding arrangements alone.
These findings have important implications for equine management, particularly for performance horses (such as racehorses or sport horses in hot climates) exercised early in the morning. When horses consume most of their forage in the evening and eat little overnight, their stomachs may be relatively empty by the time exercise begins. This increases the risk of gastric acid exposure to sensitive tissues, as the protective fibre mat and saliva buffering are diminished. Such conditions are associated with a higher likelihood of developing gastric ulcers.
Management strategies should therefore aim to extend forage consumption into the later hours of the night. Tools such as slow-feeding hay nets, smaller mesh sizes, or staggered feeding times can help prolong chewing activity and maintain a more consistent presence of forage in the stomach. Aligning feeding practices with natural circadian rhythms may improve gastric health, comfort, and overall performance.
Another important observation from overnight feeding studies is the variability among individual horses. Differences in chewing patterns may reflect aspects of equine social biology, such as vigilance behaviour. In herd settings, horses rotate periods of rest and alertness to maintain group safety. Even in isolation, some horses may retain these tendencies, leading to variations in nighttime feeding and resting behaviour. Personality, stress levels, and prior management experiences may also contribute to these individual differences.
Take-Home Message
Taken together, the combined research highlights that feeding behaviour in horses is shaped by a dynamic interplay between diet composition, forage availability, biological rhythms, and individual traits. There is no single feeding strategy that suits all horses. Instead, optimal management requires careful observation and adaptation to each horse’s behaviour and needs.
Small changes — such as adjusting forage delivery methods, modifying concentrate composition, or timing feedings more strategically — can have meaningful impacts on feeding patterns and digestive health. By integrating knowledge of satiety mechanisms with an understanding of natural circadian rhythms, horse owners and managers can create feeding programs that better mimic natural grazing conditions, even within the constraints of modern stabling.
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