Effects of Oregano Essential Oil (Origanum onites L.) Supplementation on Growth and Biochemical Metabolites in Merino Lambs

Abstract

After the prohibition of antibiotic usage to improve performance, the breeders have guided to natural resources for this purpose. Essential oils have many beneficial effects and they are ideal to use as a growth promoter feed additive in livestock. In our study for this reason, we used oregano essential oil (Origanum onites L.) in the treatment groups. Thirty Merino lambs (aged of 2.5 month and weighted average 30±0.1 kg) were housed in 45-day to determine the effects of oregano oil on the growth and biochemical metabolites. The main ration includes consisting of concentrate and alfalfa hay. In the control group oregano essential oil was not added. The second group (ORG 250) was supplemented with 250 mg/d oregano essential oil, third group (ORG 500) also were supplemented with 500 mg/d. Bloods were taken from 8 animals for each group in the initial and end of the study. Samples were collected into anticoagulant tubes and plasma were allocated into microtubes and stored until the analysis day. There were statistically differences in growth hormone (GH), total protein, triglyceride, AST concentrations in ORG 500 group at 45th day (p