DIURNAL VARIATIONS IN TESTOSTERONE, PROLACTIN AND HAEMATOLOGICAL PARAMETERS IN THE NIGERIAN INDIGENOUS COCK

Résumé

Hormones, such as testosterone and prolactin, play essential roles in growth, reproductive and physiological functions of animals. This research focused on the diurnal variation in the concentrations of testosterone and prolactin in Nigerian indigenous cocks, exploring the impact of photoperiod on hormone secretion. Six (6) adult cocks of domestic chicken each from a group of four (4) birds weighing about 1.00 kg to 1.50 kg were used in this study. Blood samples were collected every two hours over a 24-hour period, with subsequent analysis for testosterone and prolactin concentrations. Blood parameters such as white blood cell count, red blood cell count and hemoglobin concentration were also examined. Results indicated significant (P<0.05) diurnal variations in testosterone secretion peaking in the morning (1.27 ng/mL) and declining in the evening (0.79 ng/mL). Prolactin, while not significantly (P>0.05) different over the 24-hour period, exhibits diurnal variations. Red and white blood cell counts are higher during daylight hours, emphasizing the
influence of activities and exposure to stress during the day. In Conclusion, this research showed that photoperiod have significant effects on the secretion of testosterone and considerable diurnal variations in the concentrations blood parameters examined. This highlights the importance of considering diurnal variations and photoperiod in hormone concentration studies, providing valuable insights into the reproductive and physiological dynamics of Nigerian indigenous cocks.