Evaluations of the diurnal variations in the haematological profiles of domestic fowls

Abstract

The diurnal fluctuation in the haematological parameters of the domestic fowls was investigated using twenty four (24) male Isa Brown chickens. Twenty four (24) apparently healthy Isa Brown chickens of average mean weight 1.99±0.12 kg (1.85-2.30kg) aged 18 weeks were used for this study. The Isa Brown chickens (24) were randomly assigned to four treatment groups (A to D) of six chickens per group in a completely randomized design (CRD). Group A: Early morning (6am), Group B: Afternoon (12pm), Group C: Evening (6pm) and Group D: Mid Night (12am). Blood samples were collected from the birds at 6:00 am, 12:00 pm, 6:00 pm and 12:00 am, during a 12-hour light and a 12-hour dark period at a six hourly intervals. The mean haemoglobin (Hb) concentration (10.40±0.09g/dl) and packed cell volume (31.00±0.41%) at 12am were significantly (P < 0.05) higher than the other diurnal periods of the day. The mean red blood cell count (RBC) at early morning (6am) was significantly (P < 0.05) higher than the values at 12pm but showed no significant (p > 0.05) difference when compared to the values at 6pm and 12am. The mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) concentrations at 12pm were significantly (P < 0.05) higher when compared to the 6am values. The mean total leucocyte count (TLC), lymphocyte count and monocyte count at 6am were significantly (P < 0.05) higher than the values at 6pm. There was however no significantly (p > 0.05) variations in the mean corpuscular haemoglobin concentrations (MCHC), heterophil count, eosinophil count, basophil count and heterophil/lymphocyte (H/L) ratio among all the diurnal periods investigated. In conclusion, the haemoconcentration produced in this study might be responsible for the higher haematological parameters during the night (12am) and early morning (6am) because the birds were neither feeding nor drinking water at this period of the day