Seasonal Variation in the Haematological Parameters of the Adult Mallard Duck in a Tropical Environment

Abstract

Duck production is a growing poultry enterprise in Nigeria and they are mostly reared in extensive management system. However, the haematological profiles as influenced by the tropical environment have not been well documented. The objective of the present study was to examine the seasonal variation in the haematological parameters of the adult Mallard duck in the tropical environment of Nigeria; as they effects duck production adversely. The Erythrocyte, leucocyte and platelet counts, as well as the erythrocyte osmotic fragility of the domestic duck of the mallard breed during the wet and dry seasons in the hot humid tropical environment of the Experimental Animal Unit of the Department of Veterinary Physiology, Biochemistry and Pharmacology, University of Ibadan, Ibadan, Nigeria was investigated. The study showed that the values of the packed cell volume (PCV), mean corpuscular haemoglobin (MCH) and platelet were significantly higher in the dry season than in the wet season, but the red blood cell (RBC), haemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), total and differential leucocyte values were similar in the two seasons. The erythrocyte fragility was also higher in the dry season. In conclusion the higher PCV, MCH and platelet values in the dry season might have resulted from haemoconcentration occasioned by higher evaporative heat loss, which is a common occurrence in the dry season. The higher erythrocyte fragility could have been the result of stress induced by the high ambient temperature during the dry season, or higher metabolic rate associated with lactic acid accumulation, which has been shown to increase erythrocyte osmotic fragility.