EVALUATION OF DIETARY ESSENTIAL OILS AS NATURAL ANTIFUNGAL AGENTS AGAINST ASPERGILLUS INFECTION IN BROILER CHICKENS
Keywords:
Avian Aspergillosis, Broiler Nutrition, Essential Oils, Origanum vulgare, Phytogenics, Thymus vulgaris.Abstract
Background: Avian aspergillosis, primarily caused by Aspergillus fumigatus, poses a significant threat to global broiler production, leading to respiratory distress, immunosuppression, elevated mortality, and reduced feed efficiency. With growing restrictions on synthetic antimicrobials and antifungal resistance concerns, dietary phytogenic compounds offer a viable, natural therapeutic alternative.
Objective: This study evaluated the protective efficacy of dietary supplementation with thyme oil and oregano oil, individually and in combination, against experimentally induced Aspergillus infection in broiler chickens.
Methods: A total of 100 broiler chickens were randomly allocated to four treatment groups: Control (0 mg/kg), Thyme Oil (350 mg/kg), Oregano Oil (350 mg/kg), and Thyme+Oregano Combination (350 mg/kg total). Birds were monitored over 42 days. Parameters evaluated included growth performance, pulmonary Aspergillus fungal burden, culture positivity rate, and pulmonary lesion severity scores. Data were analyzed using One-Way ANOVA, Tukey's HSD post-hoc test, and Kruskal-Wallis tests.
Results: Oregano Oil and Thyme Oil significantly improved final body weight (2008.77 ± 74.02 g and 1985.00 ± 64.71 g vs. 1919.80 ± 74.05 g in Control; p<0.01). FCR significantly improved in Oregano Oil (2.04 ± 0.08) and Thyme Oil (2.06 ± 0.07) groups (p<0.01). Fungal load was markedly reduced by Oregano Oil (1.26 ± 0.64 log10 CFU/g) and Thyme Oil (1.45 ± 1.17 log10 CFU/g) compared to Control (3.46 ± 2.52 log10 CFU/g; p<0.001). Culture positivity dropped from 48% in Controls to 8% in Oregano Oil and 12% in Thyme Oil groups. Lesion scores were lowest in Oregano Oil (0.96 ± 0.79) and Thyme Oil (1.52 ± 0.87) compared to Control (2.20 ± 0.58; p<0.05). The combination treatment showed less efficacy, indicating potential competitive antagonism.
Conclusion: Dietary supplementation with individual oregano or thyme essential oil at 350 mg/kg significantly mitigates Aspergillus infection in broiler chickens. Monotherapy with oregano oil demonstrated the highest efficacy.
