Performance, serum biochemical indices and crude protein utilisation by broiler chickens fed diets based on two varieties of cassava (Manihot esculenta Crantz) grits I. Starter Phase

Résumé

Effect of dietary inclusion of cassava grits (Manihot esculenta Crantz) from two cassava varieties TME 419 and TMS 01/1371 as replacement for maize on performance, serum biochemical indices and crude protein utilization of broiler chicks was investigated in a three-week trial with Abor Acre plus broiler chicks (n=210). In a completely randomized design, birds were allotted to seven treatments, each replicated thrice with 10 birds per replicate. Diet 1 comprised 50 % maize and 0 % cassava grits, diets 2, 3 and 4 had their respective maize content replaced at 25, 50 and 75 % with cassava grits from TMS 01/1371 while diets 5, 6 and 7 was replaced correspondingly with cassava grits from TME 419 at 25, 50 and 75 %, respectively for a duration of 21-day. Increased dietary cassava grits significantly lowered (P<0.05) weight gain and metabolizable crude protein of broiler chicks. Birds on diets 3, 4, 6 and 7 had similar weight gain, feed conversion ratio and metabolizable crude protein. Except for significantly increased (P<0.05) total protein and alkaline phosphatase due to interactions of cassava varieties and inclusion levels, effects of cassava varieties and inclusion levels on other serum indices were similar (P>0.05). Regression of metabolizable crude protein on graded cassava grit inclusion for both varieties were negative and significant (P<0.05) for TME 419 (R² =0.355) and highly significant (P<0.01) for TMS 01/1371 (R² =0.6639). Both graphs clearly depicted decreased metabolizable crude protein due to increased cassava grits in the diets. Increased dietary cassava grits of both varieties resulted in lowered metabolizable crude protein and serum indices with concomitant increased feed conversion ratio of broiler starter chicks.