Gebremedhin Kifle G, Fonseca Vinicius D F C, Maia Alex S C
Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 2503, USA.
Animal Biometeorology Laboratory, São Paulo State University, Jaboticabal 14884-900, SP, Brazil.
Animals (Basel). 2023 Oct 3;13(19):3087. doi: 10.3390/ani13193087.
The physical properties (hair diameter, hair length, haircoat depth and haircoat density) and spectral properties (absorptivity, reflectivity, transmissivity) of the hair and haircoat of cattle are inputs to heat and moisture exchange between the skin surface and the surrounding environment, and thus play a critical role in body temperature regulation. Physical and spectral properties of haircoats also play an important role in protecting the skin against penetration of ultraviolet radiation. The focus of this review is to identify accurate and consistent measurement procedures of these properties. Additionally, the paper shows the utilization of the properties on heat exchange models and their implications on voluntary thermoregulation of cattle. To highlight the effects and benefits of haircoat color vis-à-vis solar radiation and its implication on ecological habitation, a brief explanation is provided using polar bears (white haircoat in a cold environment) and black goats in a hot desert environment.
牛毛发及被毛的物理特性（毛发直径、毛发长度、被毛深度和被毛密度）和光谱特性（吸收率、反射率、透射率）是皮肤表面与周围环境之间热量和水分交换的输入因素，因此在体温调节中起着关键作用。被毛的物理和光谱特性在保护皮肤免受紫外线辐射穿透方面也起着重要作用。本综述的重点是确定这些特性准确且一致的测量程序。此外，本文展示了这些特性在热交换模型中的应用及其对牛自主体温调节的影响。为突出被毛颜色相对于太阳辐射的影响和益处及其对生态栖息地的影响，以北极熊（寒冷环境中的白色被毛）和炎热沙漠环境中的黑山羊为例进行了简要说明。
