JOURNAL OF THE HELLENIC VETERINARY MEDICAL SOCIETY, cilt.73, sa.4, ss.4965-4972, 2022 (SCI-Expanded)
In this study, the effect of dietary supplementation of oregano and rosemary essential oils (EO) on growth performance and cecal microbiota of broilers were investigated. A total of 450 1-d-old male Ross-308 broilers were divided into 5-experimental groups (10 replicates of 9 chickens): a Control (C), fed a basal diet; four treatments, which received a basal diet supplemented with oregano and rosemary EOs individually (O, 300 mg/kg oregano EO; R, 300 mg/kg rosemary EO) and combined (OR1, 150 mg/kg oregano EO + 150 mg/kg rosemary EO; OR2, 200 mg/kg oregano EO + 200 mg/kg rosemary EO). Body weight (BW), feed intake (FI), body weight gain (BWG), feed conver-sion ratio (FCR), and cecal microbiota (coliforms, clostridia and lactobacilli) were determined weekly, and at 42 d, re-spectively. BW in R (p < 0.05) and OR2 (p < 0.001), and BWG and FCR in OR2 (p < 0.05) were significantly higher than C at 42 d, despite no difference in FI in any group during experimental period. Counts of cecal coliforms (p < 0.001) and clostridia (p < 0.01) decreased, and lactobacilli (p < 0.001) increased substantially between C and treatment groups. Results indicated that combined oregano and rosemary EO (200 mg/kg ea) supplementation significantly increased BW and BWG, improved FCR in 1-42 d, lowered coliform and clostridial, and increased lactobacilli counts suggesting a beneficial shift in cecal microbiota.