PERFORMANCE, CARCASS, HAEMATOLOGY AND BLOOD CHEMISTRY OF BROILERS FED ON COOKED WILD COCOYAM [ Colocasia esculenta   (L.) Schott] CORMS AS PARTIAL SUBSTITUTES FOR MAIZE

A 28-day feeding experiment was carried out to investigate the performance, carcass and health status of broilers fed Cooked Wild Cocoyam [Colocasia esculenta (L.) Schott] Corm (CWCC), as partial substitutes for maize. One hundred and twenty (120) 4-weeks old Hybro broiler chicks were randomly distributed to four dietary treatments of three replicates each. There were 10 birds per replicate in a completely randomized design experiment. Four diets were formulated such that diet 1 contained no CWCC and served as the control, while diets 2, 3 and 4 contained 10, 20 and 30% CWCC respectively. Results indicated that the highest weight gain (304.48g/b/wk) obtained in the control reduced to 260.87, 254.58 and 253.03g/b/wk respectively for birds fed 10, 20 and 30% CWCC-based diets (P < 0.05). The feed conversion ratio (2.56) of birds fed with 0% CWCC-based diet increased to 2.92, 3.12 and 3.24 respectively for those fed 10, 20 and 30% CWCC-based diets (P < 0.05). Mortality was the same across all dietary treatments. The dressed weight (64.78%) of the control decreased to 62.93, 61.01 and 60.57% respectively for birds fed 10, 20 and 30% CWCC-based diets(P < 0.05).The heart weight (HW) and gizzard weight (GW) differed significantly (P < 0.05) across the dietary treatments. All the haematological parameters did not differ (P > 0.05) among the dietary treatments. The value of cholesterol was 134.54, 132.80, 125.48 and 121.91mg/dl respectively at 10, 20 and 30% CWCC. Cost of a kilogramme of feed significantly (P < 0.05) decreased from ₦50.01 (control) to ₦38.42 (10% CWCC), ₦36.84 (20% CWCC) and ₦35.26 (30% CWCC) respectively. Cost of feed per kilogramme weight gain(₦127.86) obtained in birds on control (0% CWCC-based diets) was significantly (P<0.05) higher than ₦112.19, ₦114.82 and ₦114.36 respectively for 10, 20 and 30% CWCC-based diets. Although substitution of maize with CWCC at 10-30% was cheaper than control with no adverse effect on bird’s health, however, the weight gain, dressed weight, cost per kg feed and cholesterol level decreased (P < 0.05) with increasing substitution levels and birds fed 10% CWCC-based diets had the least cost of feed per kg live weight gain. Therefore, 10% level of substitution was recommended for optimum profitability.

Keywords
Cooked wild cocoyam; anti-nutrients; broilers; blood indices; replacement; performance