Sexual Dimorphism of Male and Female Bali Cattle (Bos javanicus) Hair Morphology

Abstract

Sexual dimorphism in mammals is a fundamental aspect of biological diversity, often reflected in physical characteristics, including hair structure. This study aims to investigate sexual dimorphism in the hair structure of Bali cattle (Bos javanicus) by comparing samples from three male and three female. Observed parameters included macroscopic and microscopic characteristics of dorsal and ventral hair. The results showed differences between male and female Bali cattle. Male Bali cattle have shorter hair and a smaller diameter than female cattle. Male hair tends to be more blackish-brown, while female hair is yellowish-brown. The cuticle structure of male and female cattle does not differ, with a regular to irregular wave pattern and smooth to rippled scale edges. However, the scales of male Bali cattle appear denser. The medulla of male and female Bali cattle has a lattice structure and a multicellular composition, with a higher medulla index in male than in female cattle. These findings indicate that sexual dimorphism in the hair structure of Bali cattle not only reflects biological differences between males and females but also as a mechanism of thermoregulation. The results of this study have potential applications in livestock management and breeding programs.