Interplay of hormones and metabolite excretion with fern pattern prove saliva as a potent indicator of male reproductive status in Kangayam breed cattle.

Kangayam cattle are one of the drought breeds in India with distinct attributes. Agricultural transformation has led to a decline in many pure-breed indigenous cattle, including the Kangayam breed. Hence, a study on the reproductive physiology of male Kangayam breed cattle is necessary to disentangle problems in the area of livestock improvement. In this study, we investigated the relationship between serum hormones and bio-constituents and ascertained the potential of saliva as an indicator of the reproductive status of Kangayam cattle (Bos indicus). The present study confirms that cholesterol was higher in intact males and lower in prepubertal and castrated males. Testosterone levels were also higher in intact males than in castrated or prepubertal males. Hence, it can be inferred that high cholesterol levels contribute to active derivatization of testosterone in intact males. In contrast, reduced cholesterol availability leads to decreased testosterone synthesis in castrated and prepubertal males. Furthermore, it is reasonable to speculate that testosterone could have influenced salivary fern patterns in intact males, and thus, fern-like crystallization in the saliva was apparent. The unique salivary compounds identified through GC-MS across various reproductive statuses of Kangayam males may advertise their physiological status to conspecifics. In addition, the presence of odorant-binding protein (OBP) in saliva further supports its role in olfactory communication. This study attested to a posssible interlink between gonadal status and serum biochemical profiles. The salivary fern pattern revealed in this study can be used as a predictive tool, and the presence of putative volatiles and OBP adds evidence to the role of saliva in chemical communication.