What protective function does the dark pigmentation often found beneath the Zebu coat serve?

Buffering intense UV radiation in equatorial latitudes

Although Zebu coat color can vary widely—encompassing shades like white, gray, red, and black—the skin located underneath the hair frequently displays significant dark pigmentation. This dark underlying color is a crucial evolutionary feature that offers vital protection against the constant challenge of intense UV radiation prevalent in the equatorial latitudes where these animals naturally thrive. This dark pigment acts as a buffer, absorbing and mitigating the damaging effects of the sun's intensity. A lighter-skinned animal, even one covered by a white coat, would be highly susceptible to severe sunburn and consequential skin damage without this protective melanin layer beneath the surface.