A total of two hundred twenty five one-day-old Indian river broiler chicks (IR) were distributed into five different treatment groups (A, B, C, D and E), of three replicates (15 chicks / replicate). The chicks in control group (A) were fed control diet with β- mannanase (Hemicell®), groups B and C were fed diets containing SFM (2.5 and 5%, respectively) without β-mannanase (Hemicell®). While groups D and E were fed diets containing SFM (2.5 and 5%, respectively) with β-mannanase (Hemicell®). Effects of inclusion Sunflower meals with or without β-mannanase (Hemicell®) on performance showed that groups containing Sunflower meals 2.5%with or without enzyme show improvements than other groups. Erythrogram profile showed a significant (p≤0.05) difference between control group and other groups in Hb, RBCs, PCV and MCV levels, while there was a significant (p≤0.05) increase in MCH and MCHC in group E (SFM 5%+Hemicell®) when compared with other groups. Leukogram showed non significant changes between control group and other groups. It was concluded that inclusion of sunflower meals 2.5% had a positive role in improvement final body weight changes and final body weight gain. Partial replacement diet with sunflower meals (2.5 and 5% with or without Hemicell®) did not induce side effects on hematological parameters.