Effects of feeding cassava root meal and local fish meal on growth performance and carcass characteristics of broilers

An experiment was carried out to investigate the effects of replacing maize meal with cassava root meal (CRM) in broiler diets. The effects of including 5% “Small fish” meal (Fm) in these CRM diets were also studied. 240 one week old mixed sexes broiler chicks were divided into 2 blocks in time, and each clock had 8 treatments composed of 0, 10, 25 and 49=0% CRM, with 5% FM or without FM. Each experimental unit had 15 birds which were fed on the experimental diets for 7 weeks. The energy and protein content of the diets in all the treatments were nearly the same. Weight gains were significantly reduced when the dietary CRM level exceeded 10%. At 0, 10, 25 and 40% dietary CRM level, the mean weight gains were 1175.2, 1265.9, 1109.4 and 983.1g respectively. Live weight at slaughter and dressed carcass weight decreased significantly when dietary CRM level was in excess of 10%, but no significant treatment differences were observed when the dressed carcass weight was expressed as a percentage of live weight. The proportions of non-carcass components and carcass chemical components were also not significantly affected by dietary CRM level. There was, however, a tendency for the carcass fat percentage to increase and the carcass crude protein percentage to decrease with increasing dietary CRM level. Increasing level of CRM in the diet did not significantly affect the dietary crude protein and metabolizable energy utilization. The birds fed diets with 40% CRM gave the highest gross margin/kg carcass produced when FM was not included in the diets. The inclusion of 5% FM resulted in insignificant improvements in live weight gain. At 0, 10, 25 and 40% dietary CRM level, the mean weight gains for birds on 5% dietary FM were 1184.6, 1311.5, 1184.1 and 1009.7g respectively, while mean weight gains for birds on 0% dietary FM were 1165.8, 1220.3, 1034.7 and 956.5g respectively. Live weight at slaughter, dressed carcass weight, proportions of non-carcass components and carcass chemical components were also not significantly affected by the inclusion of 5% FM in the diets. There were no significant differences in dietary crude protein and metabolizable energy utilization between the birds on different dietary FM levels. When the gross margin/kg carcass was considered, there was a general tendency for it to be higher in birds fed diets containing 5% FM. The birds fed 10% CRM and 5% FM in the diets gave the highest gross margin/kg carcass produced.