Effect of feeding cassava (Manihot esculenta Crantz) root meal on growth performance, hydrocyanide intake and haematological parameters of broiler chicks.

The effect of feeding cassava root meal on growth performance, hydrocyanide intake, haematological indices and serum thiocyanate concentration of broiler chicks was investigated using 300-day-old male broilers. There were five dietary treatments arranged in a 2 × 2 + 1 factorial arrangement of two processing methods of cassava root (peeled and unpeeled) included at two levels (100 and 200 g/kg) plus a control diet (maize-based diet, containing no cassava root). Each treatment was replicated six times with ten birds per replicate. The feeding trial lasted for 28 days. Control-fed birds had the highest overall (P < 0.01) final liveweight and weight gain, least (P < 0.05) hydrocyanide (HCN) intake and best (P < 0.05) feed-to-gain ratio. Chicks fed with control and diet containing 100 g/kg peeled cassava root meal (PCRM) had the least (P < 0.05) feed cost per weight gain. Chicks fed with diet containing 100 g/kg cassava root meal had higher (P < 0.05) final liveweight and weight gain and reduced (P < 0.05) HCN intake than chicks fed with diet containing 200 g/kg cassava root meal. Dietary inclusion of peeled cassava root meal (PCRM) for broiler chicks resulted in increased final liveweight (P < 0.05), weight gain (P < 0.01) and feed intake (P < 0.01) when compared with birds fed with diet containing unpeeled cassava root meal (UCRM). The least (P < 0.01) final liveweight and weight gain and worst (P < 0.05) feed-to-gain ratio were obtained with chicks fed with diet containing 200 g/kg UCRM. Increased dietary inclusion levels of cassava root resulted in significant increase (P < 0.05) in white blood cell (WBC) count, heterophil count and serum thiocyanate concentration. In comparison with chicks fed with diet containing UCRM, dietary inclusion of PCRM resulted in increased (P < 0.05) red blood cell (RBC) count and haemoglobin (Hb) concentration and reduced (P < 0.05) white blood cell (WBC) count and serum thiocyanate concentration. Although inclusion of 100 g/kg PCRM showed some economic sense, dietary inclusion of either peeled or unpeeled cassava root poses a threat on growth and health status of broiler chicks.