Chemical Composition and Dietary Effects of Pennyroyal and Dill on Biochemical, Hematological, and Oxidative Stress Biomarkers in Broiler Chickens

The current study was conducted to determine chemical constituents present in M. pulegium L and A. graveolens L. essential oils and investigate dietary effects of the herbal powders on some biochemical, hematological and oxidative stress parameters. A 42-day fully randomized trial was conducted using 240 broilers (Ross 308) divided into 4 main groups with three replicates, supplemented with the aerial parts of the plant materials as follows: (I) Control (corn-soybean meal only); (II) 1% pennyroyal; (III) 1% dill; (Ⅳ) the combination (0.5% pennyroyal+0.5% dill). Numerous active compounds were detected in the essential oils of both plants. 1,8-cineole was found to be the major constituent in pennyroyal's essential oil and Carvone in dill. The serum cholesterol, triglyceride as well as High and Low Density Lipoprotein (HDL and LDL) levels were significantly different among treatments (P< 0.05). However, the combination of both plants had more pronounced effects on the aforementioned parameters. A significant increase in total protein content also was observed in the groups supplemented with herbal powders. Nevertheless, dill powder had no significant effect on glucose levels. Heterophil and lymphocyte counts also were different between groups (P< 0.05). Moreover, activities of glutathione peroxidase, superoxide dismutase and catalase were significantly changed following the herbal supplementation. A significant decrease in malondialdehyde content and increase in total antioxidant capacity were recorded in all supplemented groups. Conclusively, supplementation with the dried powders can improve serum biochemistry and enhance the antioxidant status. However, it seems like the combinatorial supplementation is more effective.