Effect of hay nets on subluxations, pain-pressure thresholds, and cervical range of motion in the axial skeleton of adult horses.
Authors: DeBoer M, Rieck T, Johnson L, Redenius H, Martinson K
Journal: Journal of equine veterinary science
Summary
Intensive management practices such as hay nets are increasingly used to extend feeding time and minimise waste, yet their biomechanical consequences remain poorly characterised. DeBoer and colleagues conducted a crossover trial with 13 horses over two years, alternating between feeding from round bales with and without nets (4.45 cm openings) whilst monitoring cervical subluxations via chiropractic examination, cervical range of motion, and mechanical nociceptive thresholds at the jaw, poll, and withers across three measurement periods annually. Hay net use resulted in a statistically significant 1.6-point increase in cervical vertebral subluxations compared with control feeding, alongside a 5-degree increase in cervical flexion-extension range of motion (chin-to-chest and chin-to-fetlock measurements); however, no changes were detected in temporomandibular joint position, thoracic or lumbar subluxations, or pressure pain thresholds at any measured site. Whilst the clinical significance of minor increases in cervical subluxation warrants further investigation—particularly regarding cumulative effects beyond 12 weeks and potential links to stiffness or performance—these findings suggest hay nets produce only modest musculoskeletal perturbations in adult horses under typical management conditions. Practitioners should weigh the demonstrated benefits of extended feeding time against marginal increases in cervical mobility and subluxation frequency, especially for performance animals or those with pre-existing cervical pathology.
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Practical Takeaways
- •Hay nets may contribute to increased cervical subluxations in horses; consider monitoring neck alignment and chiropractic status in horses using nets regularly
- •The increased cervical range of motion in netted hay-fed horses may indicate postural changes or compensatory neck mechanics that warrant investigation
- •While hay nets offer management benefits (reduced waste, extended intake time), the minor skeletal impacts should be weighed against their convenience in farm operations
Key Findings
- •Horses fed with hay nets (NET) showed a significant average 1.6-point increase in cervical subluxations compared to controls (P<0.05)
- •Cervical range of motion was 5 degrees greater in NET horses for chin-to-chest and chin-to-fetlock measurements (P≤0.05)
- •No significant differences were found in mechanical nociceptive thresholds at the jaw, poll, or withers between NET and CON treatments (P>0.05)
- •Hay nets had no impact on TMJ, thoracic, or lumbar vertebral subluxations over the 12-month study period (P>0.05)