Factors Affecting the Rate and Measurement of Feed Intake for a Cereal-Based Meal in Horses.
Authors: Campbell Tara E, Doughty Hunter, Harris Patricia A, de Laat Melody A, Sillence Martin N
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: Rate and Measurement of Feed Intake in Horses Rapid consumption of cereal-based concentrates poses recognised risks for gastric ulceration, colic, and stereotypic behaviours, yet little has been established about which practical management factors reliably slow intake rate in horses. Campbell and colleagues conducted four separate trials examining mechanical, dietary, temporal, and individual variables affecting oat consumption rate, involving between 6 and 71 horses across different breeds and body weights. Adding chaff proved highly effective—intake rate decreased significantly when chaff comprised more than 15% of the meal, reaching a plateau at approximately 50% addition, with this effect independent of stem length; conversely, meal size and molasses supplementation had no bearing on intake speed, whilst intake rate naturally declined substantially during a meal (from 74 g/minute in the first five minutes to 16 g/minute after 30 minutes). Breed emerged as a substantial variable, with Clydesdales consuming feed notably faster than Thoroughbreds of equivalent body weight (82 versus 66 g/minute), whilst exercise, age and sex showed negligible influence. For practitioners, these findings reinforce chaff's utility as a straightforward tool to moderate consumption velocity and reduce associated health risks, though the authors importantly emphasise that establishing standardised measurement protocols across research will be essential for meaningful comparison of intake rates in future studies.
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Practical Takeaways
- •Adding chaff at ≥15% of cereal-based meals effectively slows intake rate and may reduce risk of gastrointestinal and behavioral problems; stalk length does not matter within the tested range
- •Breed-specific differences exist in eating speed (Clydesdales faster than Thoroughbreds), so feeding protocols may need adjustment accordingly
- •Standardized measurement protocols are essential for comparing ROI data between studies, as intake rate changes substantially throughout a single meal
Key Findings
- •Chaff addition above 15% significantly decreased rate of intake (ROI), with plateau effect at ~50% addition, independent of stalk length (1.4 cm vs 4.1 cm)
- •Meal size (0.5-4 g/kg BW) and 10% molasses addition did not affect ROI in cereal-based meals
- •ROI decreased markedly during consumption from 74 g/minute in first 5 minutes to 15.8 g/minute after 30 minutes
- •Clydesdales had significantly faster ROI than Thoroughbreds of similar body weight (81.8 ± 6.8 vs 66.0 ± 3.35 g/minute); body weight affected ROI in Clydesdales but exercise, age, and gender did not significantly impact ROI