Evaluation of Peppermint and Clove oils on Growth Performance and Hematological Parameters of Broiler Chickens

Abstract

The impact of peppermint and clove oils on the growth performance and hematological parameters of broiler chickens was investigated during the 2025 season on a private farm in Bani Walid, Libya. We bought 41-day-old broiler chicks (Ross 308) from a nearby hatchery. Based on a fully randomized design, the birds were weighed upon arrival and then randomly assigned to one of nine treatments, each consisting of three replicates of 12 birds. Peppermint (PO) (200, 400, 600, and 800 mg/kg) and clove oils (CO) (150, 300, 450, and 600 mg/kg) were the dietary treatments; the control treatment was a baseline diet. The average active ingredient concentration of clove and peppermint oils was taken into consideration when selecting the dosages of dietary supplements as treatments. The results obtained indicated that increasing the amount of clove oil up to 600 mg/kg resulted in a higher value of weight gain, whereas increasing the amount of peppermint oil up to 600 mg/kg resulted in a higher value of weight gain. Additionally, the control treatment recorded higher values of feed intake and feed: grain ratio, respectively. Furthermore, increasing the amount of clove oil up to 600 mg/kg resulted in greater values of RBC, WBC, Hb, HCT, PCV, MCV, and MCH than the control treatment, which had lower values of these parameters. In contrast to the control treatment, which recorded greater values of glucose, total cholesterol (TC), triglyceride (TG), and LDL, increasing the amount of peppermint up to 800 mg/kg resulted in higher values of total protein and HDL. When taken as a whole, these results show that peppermint and clove oils can be useful natural substitutes for growth stimulants, supporting not only enhanced performance but also improved intestinal health and immunological status in broiler production systems.