Haematological and Serum Biochemical Responses of Broiler Finisher Chickens to Graded Levels of Garlic (Allium sativum) Powder in Feed
Masking synthetic growth promotants, garlic (Allium sativum) is widely studied as a natural feed additive in poultry due to its antioxidant, antimicrobial, and lipid-modulatory properties. However, effects during the finisher growth phase remain under-characterised. This study evaluated the effects of three inclusion levels of garlic rhizome powder (0.5–1.5%) on selected haematological and biochemical parameters of Abor‑Acre broilers during the 4-week finisher phase. 120 Abor‑Acre broiler chickens (day-old at placement) were reared under standard starter conditions until 4 weeks of age, then randomly allocated (n = 30/treatment) to one of four finisher diets: T1 (basal, 0% garlic), T2 (0.5%), T3 (1.0%) and T4 (1.5%) garlic powder. Each treatment had three replicates of 10 birds. Finisher diets were offered from weeks 5–8. Daily feed intake and weekly growth measurements were recorded. At the end of week 8, blood was sampled from two randomly selected birds per replicate (n = 6/treatment) for hematological analysis [hemoglobin (Hb), packed cell volume (PCV), red and white blood cell counts, mean corpuscular indices, heterophils, lymphocytes, monocytes, eosinophils] and serum biochemistry [AST, ALT, ALP, total cholesterol, total protein, albumin, globulin, uric acid, creatinine]. Data were analysed by ANOVA and Duncan’s multiple range test; significance was accepted at P < 0.05. Garlic inclusion had significant effects (P < 0.05) on haematological parameters: birds in T3 and T4 showed elevated Hb, PCV and RBC counts compared to control. Mean corpuscular volume and MCHC remained within reference ranges. Lymphocyte and monocyte proportions increased linearly with garlic dose; heterophils and eosinophils were unchanged. Serum total cholesterol declined in a dose-dependent manner (T4 ≈ 15–20% lower than T1), while creatinine remained stable across treatments (P > 0.05); AST, ALT and ALP showed small but non-significant reductions. Total protein, albumin and globulin were slightly elevated in garlic groups without adverse effects. Dietary garlic rhizome powder at 1.0–1.5% enhances finisher broiler blood profiles by improving haematological indices and lowering cholesterol, without compromising kidney function. These results support the use of garlic as a natural finisher-phase additive to promote broiler health and potentially contribute to antibiotic-free poultry production.
Keywords: Abor-Acre, finisher phase, haematology, serum biochemistry, cholesterol, garlic powder
