The study was carried out at Duware farm along Yola-Fufore Road Adamawa state. Nigeria to determine the hematological and biochemical indices, rumen pH, ammonia concentration in rumen liquor and urine pH of white Fulani (Bunaji) bull Yearling calves fed graded levels of urea and molasses ensiled rice straw supplemented with maize offal and cowpea husk. Six yearling white Fulani (Bunaji) bull calves weighed 80kg-100kg was used for the research. The treatments diets consist of graded levels of urea and molasses ensiled rice straw supplemented with maize offal in T1, graded levels of urea and molasses ensiled rice straw supplemented with cowpea husk in T2, and graded levels of urea and molasses ensiled rice straw only in T3 (control group). The feeds was offered at 8; 00 am in the morning and 6: 00 pm in the evening, remnants was weight before fresh feeds were offered, mineral lick and water was provided ad-libitum, and animals were weight weekly to determine their growth performance. Two weeks adaptation period was carried out, the experiment last for three months including the adaptation period. Techniques and statistical package for data analysis was completely randomize design (CRD) and the values were subjected to analysis of variance (ANOVA) using least significant difference (LSD) to separate the means. Results revealed that the hematological and biochemical indices PCV, RBC, WBC, HBC, MCV, MCH, MCHC, Total protein, albumin, globulin, creatinine, urea Con. Lymphocytes, Neutrophils, Monocytes were significantly (P<0.05) difference across the treatments means, but are not significantly (P>0.05) difference among T2 and T3 in Eosinophil (%),rumen pH, ammonia concentration in rumen liquor NH3(mg/100ml) and urine pH were not significantly affected (P>0.05) by the inclusion level of urea-molasses in an ensiled rice straw in the diets, it can be concluded that the hematological and biochemical indices fall within the recommended values and white Fulani (Bunaji) bull Yearling calves can be fed graded levels of urea and molasses ensiled rice straw supplemented with maize offal and cowpea husk without any deleterious effects.