Abstract
Background and Objective: Optimizing gut health is critical for sustaining poultry productivity while reducing antibiotic use. This study evaluated the effects of garlic, turmeric, ginger, and cinnamon essential oils administered via drinking water on growth, intestinal morphology, oxidative stability, and gut microbial population in broiler chickens.Methodology: A total of 200 a-day-old Arbor Acres broiler chicks weighing 38.47 ± 1.47 g were randomly distributed into five groups with control (CON), garlic essential oil (GAR), ginger essential oil (GIN), turmeric essential oil (TUR), and cinnamon essential oil (CIN), with ten replicates of four birds each, over a 42-day trial. Birds received a basal diet with essential oils in the drinking water. Growth indices, microbial counts, intestinal histomorphometry, and antioxidant status were evaluated using one-way ANOVA (P < 0.05).Main Results: GAR and CIN significantly improved final body weight and villus height in duodenum compared with CON, while TUR resulted in the lowest growth performance and poorer feed efficiency. Essential oil treatments increased feed intake, particularly in GAR, without consistent improvement in feed conversion ratio. GAR reduced cecal pathogenic bacteria (coliforms and enterococci) while maintaining Lactobacillus populations, whereas TUR non-selectively increased both beneficial and non-beneficial microbes. GAR and GIN significantly enhanced intestinal antioxidant activity, and all treatments reduced lipid peroxidation in the duodenum and jejunum.Conclusions: Supplementation of spice essential oils via drinking water improves gut health, oxidative stability, and growth performance in broilers, with garlic and cinnamon showing superior growth-promoting effects and ginger and garlic enhancing antioxidant capacity. These findings suggest that spice essential oils may have potential as phytogenic supplements capable of supporting broiler performance and intestinal health.