Effect of in-ovo injection of lavender oil and dietary supplementation of lavender powder on growth, intestine histomorphology, and serum parameters in broilers

The research was conducted at Animal Production Department, College of Agricultural Engineering Sciences, University of Duhok, Iraq. A total of 400 Ross 308 eggs were incubated, and 348 chicks were hatched. From the hatched chicks, 240 were randomly divided into 5 treatment groups, each with 4 replicates and 12 birds per pen. The treatments included a control group (no additive or injection), eggs injected with 0.05 mL of Lavender essential oil (T1), eggs injected with 0.1 mL of lavender essential oil (T2), birds fed with 0.5% lavender powder (T3), and birds fed with 1% lavender powder (T4). Results indicated that during days 0-10, birds injected with lavender essential oil (T1) exhibited significantly higher body weight gain as compared to T3 and T4. By day 24, the body weight of birds in T2 was significantly increased compared to control and T4. Treatments T1, and T3 showed significantly higher body weight gain compared to T4. Additionally, T1 and T2 reported significantly higher body weight and increased feed intake with no significant differences in feed conversion ratio among treatments by day 35. Villi height, crypt depth, tip, basal, and villi/crypt ratio was increased significantly in birds of T1 group compared to those fed a control diet. All treatments showed a higher villi height/crypt depth ratio over the control. The concentration of AST serum in control group was higher than overall treatments. It was concluded that the in-ovo injection and dietary supplementation of lavender essential oil or powder had a positive effect on broiler performance and gut health.