Efficacy and Function of Feathers, Hair, and Glabrous Skin in the Thermoregulation Strategies of Domestic Animals

Abstract

The objective of this review is to describe and analyze the effect of feathers, hair, and glabrous (hairless) skin on the thermoregulation of domestic and endotherm animals, especially concerning the uses and scope of infrared thermography (IRT), scientific findings on heat and cold stress, and differences among species of domestic animals. Clinical medicine considers thermoregulation a mechanism that allows animals to adapt to varying thermal environmental conditions, a process in which the presence of feathers, hair, or glabrous skin influences heat loss or heat retention, respectively, under hot and cold environmental conditions. Evaluating body temperature provides vital information on an individual’s physiological state and health status since variations in euthermia maintenance in vertebrates reflect a significant cellular metabolism deviation that needs to be assessed and quantified. IRT is a non-invasive tool for evaluating thermal responses under thermal stress conditions in animals, where the presence or absence of feathers, hair, and glabrous skin can affect readings and the differences detected. Therefore, anatomical regions, the characteristics of feathers, hair, glabrous skin such as structure, length, color, and extension, and strategies for dissipating or retaining heat together constitute a broad area of opportunity for future research into the phenomena of dermal thermoregulation in domestic species.

Is Continuous Monitoring of Skin Surface Temperature a Reliable Proxy to Assess the Thermoregulatory Response in Endurance Horses During Field Exercise?

“…Individual horse-related character differences may exist, such as nervousness that triggers sympathetic nerve activity associated with vasoconstriction of skin blood vessels. This neurophysiological response may explain varying reduced local T sks , decreased heat loss, and hyperthermia ( 23 , 55 , 78 , 89 ).…”

“…Horse-related factors include breed, body condition score, age, character (such as nervousness), and skin-related properties, such as sweat rate, skin thickness, blood vessel density, hair coat properties, clipping, and coat color ( 23 , 27 , 30 , 36 , 55 , 77 , 78 , 80 , 87 ). The sweat loss in the current study was subjectively scored from 1 to 3 by E-L.V., and, in retrospect, more accurate sweating scoring based on objective specific phenotypic descriptions would have been a better approach ( 88 ).…”

Selective Brain Cooling: A New Horizon of Neuroprotection

“…Heat stress occurs in extremely hot environments, resulting in an imbalance between internal demands and the environment, where the capacity to dissipate heat is altered ( 95 ). During heat stress, physiological mechanisms promote heat loss through cutaneous vasodilation and sensible heat loss by conduction, convection, and radiation due to the thermal gradient between the animal and the environment ( 96 ).…”

Understanding Chicks’ Emotions: Are Eye Blinks & Facial Temperatures Reliable Indicators?

“…Feathers of birds are good insulators, trapping heat between the skin and the feathers. Although this is a beneficial trait for birds in colder climates, it also makes losing heat in warmer climates more difficult and makes the animals more susceptible to heat stress (53). A rise in temperature in the core body, for example, in response to a stressor, means this heat also must be dissipated to the outer environment.…”