Effects of different levels of clove (Syzygium aromaticum L.) essential oil on hepatorenal histopathology and biofunction, protein profile and immunity in broiler chickens

The current study was conducted to investigate the effects of clove (Syzygium aromaticum L.) essential oil on hepatiorenal histopathology and biofunction, protein profile and immunity in broiler chickens. A 42-day fully randomized trial was conducted using 180 male broilers (Ross 308) divided into 4 main groups (15 birds in each) with three replicates, supplemented with the different levels of herbal essential oil as follow: I) Control (basal diet only); II) basal diet + 250 ppm oil; III) basal diet + 350 ppm oil; Ⅳ) basal diet + 450 ppm oil. The following indices were evaluated: relative weights of liver and kidney, renal injury biomarkers including urea and creatinine, hepatic biomarkers including the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT), protein profile including total protein, albumin and globulin and finally immunoglobulins A, G and M. Furthermore, histologic sections of liver and kidney were studied using a semi quantitative method. The obtained results indicated that clove could increase the levels of proteins and immunoglobulins dose dependently. However, the highest dose (450 ppm) could significantly alter hepatic and renal histopathology and biomarkers. Moreover, pathologic damages were more severe in liver compared to kidney. In conclusion, clove essential oil exerts beneficial effects on protein profile and immunity in broilers, however, it may damage liver and kidney in higher doses. Therefore, optimal and safe doses of the plant should be used.