Effects of Essential Oil Blend on Growth Performance, Carcass Traits and Blood Biochemical Profiles of Rainbow Rooster Chickens

The study aimed to evaluate the impact of different levels of essential oil (thymol‑cinnamaldehyde-menthol 1:1:1) blend on the growth performance, carcass traits, blood biochemical profiles and gut health of chickens was undertaken on a total of 160-day-old mixed-sex Rainbow Rooster chicks. The chicks were randomly assigned to four experimental groups (T1 to T4), each comprising 40 chicks divided into five replicates of eight chicks. T1 (control) group received no growth promoters, while the T2 group was given Enromycin at 80 g/ton feed. The T3 and T4 groups received the oil blend at 100 and 200 mg/kg of feed, respectively. Body weight gain, feed consumption, and feed conversion ratio were monitored weekly. Blood samples were collected on day 42. Carcass traits were assessed at the end of the trial. Results showed that the essential oil blend and antibiotic-supplemented groups had significantly lower average daily feed intake and improved FCR compared to the control group. There were no significant effects on carcass traits. The serum cholesterol level was significantly lower in the groups supplemented with a blend of essential oils compared to the control group, whereas total protein, albumin and uric acid did not differ among dietary treatment groups. In conclusion, essential oil blend at 100 mg/kg diet could serve as viable alternatives to antimicrobials in poultry production.