STUDY ON ROLE OF KISSPEPTIN IN REPRODUCTIVE DEVELOPMENT AND INTER-RELATIONSHIP WITH ENDOCRINE MARKERS FOR NILI-RAVI BUFFALO BULLS (BUBALUS BUBALIS)

Kisspeptin, a neuropeptide, is known to be a regulator of the hypothalamic-pituitary-gonadal axis and is considered to have a role in the onset of puberty. The objective of the present study was to investigate the potential role of kisspeptin and its correlation with anthropometric parameters, testicular biometry, serum profiles of reproductive as well as selected metabolic hormones in prepubertal and postpubertal Nili-Ravi buffalo bulls (Bubalus bubalis). Anthropometric parameters and testicular biometry were measured, and blood samples were collected from prepubertal (n = 20) and postpubertal (n = 20) buffalo bulls during slaughtering. Serum samples were analysed for the assessment of circulating levels of kisspeptin, gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, triiodothyronine (T3), thyroxin (T4), and insulin-like growth factor (IGF-1). Results demonstrated that there was a non-significant change in serum concentration of kisspeptin between prepubertal and postpubertal animals. However, concentrations of GnRH (P <= 0.001), FSH (P <= 0.05), T3 (P <= 0.01) and most of the anthropometric parameters were higher in the postpubertal calves than the prepubertal calves. Correlation analysis revealed that LH had significant correlation (P <= 0.05) with testicular developmental parameters and IGF (P <= 0.01) in postpubertal calves. Kisspeptin showed positive correlations (P <= 0.05) with the width of the chest and width of the pelvis in prepubertal and postpubertal calves respectively. The IGF, testosterone, and T3 also have shown associations with some of the anthropometric parameters showing their roles in the pubertal development of calves. In conclusion, the circulating level of kisspeptin did not influence either reproductive or selected metabolic hormones suggesting that there are some other unknown mechanism(s) that influence the reproductive developments of buffalo bulls which need to be addressed in further studies.