Thermographic Evaluation of the Lower Critical Temperature in Weanling Horses

University of Kuopio, Kuopio, Northern Savo, Finland
Journal of Applied Animal Welfare Science (Impact Factor: 0.74). 02/2007; 10(3):207-16. DOI: 10.1080/10888700701353493
Source: PubMed


Accommodating weanling horses in loose housing (sleeping hall with deep-litter bed and paddock) environments in winter at northern latitudes exposes the nonhuman animals to low ambient temperatures. We determined the heat loss of nine weanling horses in a cold environment by infrared thermography to assess their thermoregulatory capacity. The rate of heat loss was 73.5 to 98.7 W/m2 from the neck and 69.9 to 94.3 W/m2 from the trunk. The heat loss was higher at -16 degrees C than at 0 degrees C and -9 degrees C (p</=.01), indicating that the lower critical temperature may have been between -9 degrees C and -16 degrees C. Surprisingly, the heat loss from the trunk was less at -23 degrees C than -16 degrees C (p<.05). The frost on the surface of the hair coat at -23 degrees C probably disturbed the thermographic examination. Thus, thermography is not necessarily suitable for determining heat loss at very cold temperatures. Our results emphasize the importance of taking the housing temperature into account in planning the feeding of cold-housed weanling horses in northern latitudes.

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    • "Abbreviations: Num DF, numerator degrees of freedom; Den DF, denominator degrees of freedom; F-test, F-statistic; Pr>F, the probability associated with an F-statistic. more mature horses (Autio et al., 2007), thus their motivation to seek shelter is higher. Further research that looks into the ideal number of sheds or shed space available to outdoor-housed horses should take age dynamics into consideration. "
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    Full-text · Article · Sep 2010 · Journal of Veterinary Behavior Clinical Applications and Research
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