Hair and hair-coat properties are significant because they are inputs to heat and mass transfer models of animals. They work as an interface between animal and animal hair coat. Moreover, hair and hair-coat properties help us to select animal breed for different environment. Therefore, it is useful to identify heat tolerant cows. For hair and hair-coat properties, there are physical properties (hair length, hair diameter, density of hair coat, depth of hair coat, and weight of hair coat) and optical properties (absorptivity, reflectivity, and transmissivity). There are many factors such as body location of hairs, climates, and breeds that affect physical properties of hair coat of cows. The optical properties of hair coat of cows are significantly affected by hair-coat color.