Individual and combined effects of dietary supplementation of probiotic and essential oil on the growth performance, immunity status, gut health and jejunal histomorphology of broiler chickens

The present study was conducted to evaluate the individual and combined effects of probiotic and essential oils on the performance of broilers. Day-old broiler chicks (240) were allocated to 5 groups in completely randomized design to give 6 replications per treatment group with 8 birds in each replicate. The birds of different groups were supplemented with antibiotic growth promoter (CTC 15%) at the level of 335 mg/kg (T-1), essential oil formula (TCLVC 1.5x) (T-2), L. fermentum NKN51 (107 cfu/g) along with MOS (0.3%) and sodium butyrate (0.03%) (T-3), and combination of L. fermentum NKN51 (107 cfu/g) and essential oil formula (TCLVC 1.5x) in presence of MOS (0.3%) and sodium butyrate (0.03%) (T-4). The control group was provided basal diet only with no other supplementation. The birds were reared for a period of 6 weeks and examined for growth performance including weekly body weight, average daily gain, weekly FCR, average feed intake, cell mediated and humoral immunity, gut microbiology, jejunal histology and stress parameters including heterophil-lymphocyte ratio and serum corticosterone levels. The group supplemented with combination of probiotic and essential oil formula (TCLVC 1.5x) had significantly better growth performance, cell mediated and humoral immunity and improved jejunal histology in terms of villus height, villus width, VH: CD ratio and intestinal absorptive surface area. No significant difference was observed in stress levels of different groups in terms of heterophil-lymphocyte ratio and serum corticosterone levels. The study depicted that combined supplementation of probiotic and essential oil had affirmative response on performance parameters of broiler chickens.