Horses wearing a blanket or rug in the winter ate less hay than their non-blanketed neighbours, a recent study has found.
Healthy horses maintain their body temperature within a narrow range (98.5°F to 101°F / 36.9°C to 38.3°C) despite a wide variation in environmental conditions.
In cold weather, they use various physiological and behavioural methods to conserve body heat, such as piloerection (hair bristling), shivering, and facing away from the wind. Eating roughage generates heat and so helps maintain body temperature.
Research by Michelle De Boer and others at the University of Wisconsin-River Falls in the US, assessed the effect of wearing a blanket on horses’ feed intake, body weight (BW), and body condition scores (BCSs). A report of the work has been published in the Journal of Equine Veterinary Science.
The project was carried out over the winter of 2019-2020, when environmental temperatures typically average about -10°C.
Sixteen adult horses were recruited to the study: eight wore a medium weight blanket; the others did not. All horses lived in a dry lot and were fed grass-legume hay ad-lib. The researchers recorded hay intake and monitored horses’ body weight and condition score before, during and at the end of the study.
Horses without blankets maintained their body weight and condition score despite the cold weather.
The researchers found that the average estimated dry matter intake (DMI) was lower for blanketed horses (2.31% BW) than for non-blanketed ones (2.51% BW) – equivalent to an average of 1kg daily.
The results suggest horses wearing blankets conserve energy leading to decreased feed intake.
The researchers emphasised that, when blanketing a horse, it is important to monitor them regularly to evaluate health, welfare, body weight and condition.
Dry Matter Intake, Body Weight, and Body Condition Scores of Blanketed and Nonblanketed Horses in the Upper Midwest
Michelle De Boer, Alexandra Konop, Bailey Fisher, Krishona Martinson.
Journal of Equine Veterinary Science (2020) vol 94, 103239