[Show abstract][Hide abstract] ABSTRACT:
A change in management from pasture to stabling is a risk factor for equine colic.
To investigate the effect of a management change from pasture with no controlled exercise to stabling with light exercise on aspects of gastrointestinal function related to large colon impaction. The hypothesis was that drinking water intake, faecal output, faecal water content and large intestinal motility would be altered by a transition from a pastured to a stabled regime.
Within-subjects management intervention trial involving changes in feeding and exercise using non-invasive techniques.
Seven normal horses were evaluated in a within-subjects study design. Horses were monitored whilst at pasture 24 h/day, and for 14 days following a transition to a stabling regime with light controlled exercise. Drinking water intake, faecal output and faecal dry matter were measured. Motility of the caecum, sternal flexure, and left colon (contractions per minute) were measured twice daily by transcutaneous ultrasound. Mean values were pooled for the pastured regime and used as a reference for comparison with stabled data (Days 1-14 post-stabling) for multilevel statistical analysis.
Drinking water intake was significantly increased (pasture 2.4 ± 1.8 (mean ± s.d.) vs. stabled 6.4 ± 0.6 l/100kgBW/day), total faecal output was significantly decreased (pasture 4.6 ± 0.02 vs. stabled 1.8 ± 0.05 kg/100kgBW/day) and faecal dry matter content was significantly increased (pasture 18.7 ± 2.28 vs. stabled 27.2 ± 1.93%DM/day) on all days post-stabling compared to measurements taken at pasture (p<0.05). Motility was significantly decreased in all regions of the large colon collectively on Day 2 post-stabling (-0.77 contractions/min), and in the left colon only on Day 4 (-0.62 contractions/min) (p<0.05).
There were significant changes in large intestinal motility patterns and parameters relating to gastrointestinal water balance during a transition from pasture to stabled management, particularly during the first 5 days.
[Show abstract][Hide abstract] ABSTRACT:
Management regimes have been identified as risk factors for equine intestinal motility disorders. However, it is not known how management factors affect gastrointestinal motility.
Large intestinal motility was similar in horses on a stabled and a pastured management regime.
To investigate the effect of 2 different management regimes on large intestinal motility assessed with ultrasonography.
A within-subjects crossover design was used to compare large intestinal motility between a stabled and a pastured regime in 16 working horses. Group A was managed under a standardised stabled regime throughout the study. Group B was maintained at pasture for the first monitoring phase and then transferred to the stabled regime for the second monitoring phase. Motility of the caecum, sternal flexure and aboral left ventral colon (contractions/min) was measured twice daily for 2 consecutive days using transcutaneous ultrasonography. Mean values for each management regime were pooled for analysis using multilevel statistical modelling.
Significant variables identified by the model included: time of day, region of intestine, management regime, and combination of region of intestine and management regime. Motility assessed by ultrasound was significantly lower in stabled horses compared to pasture-kept horses. Intestinal motility for caecum was 1.7 ± 0.3 contractions/min (pastured = 2.0, stabled = 1.4), sternal flexure was 1.6 ± 0.2 contractions/min (mean (pastured = 1.7, stabled = 1.5), and left ventral colon was 0.8 ± 0.3 contractions/min (pastured = 1.0, stabled = 0.7).
The null hypothesis was disproven. Large intestinal motility assessed by ultrasound was significantly reduced in stabled horses compared to pastured horses. This effect was most marked in the aboral left ventral colon.
This study has demonstrated a possible mechanism for the increased risk of large intestinal impactions in stabled horses.