Abstract

A research study was conducted to investigate the effect of dietary inclusion of thyme powder as an antibiotic growth promoter substitution on performance, immune responses, hematological and biochemical parameters in broiler chicks. In this study, 192 day old chicks (Ross 308) were allocated to four treatments with four replicates based on a completely randomized design. Dietary treatments included control, antibiotic (flavophospholipol), and 5 and 10 g/kg thyme powder. Supplementing the diet with antibiotic and 5 g/kg thyme resulted in a significant increase in body weight (P<0.05). Feed intake of broilers was not markedly influenced by treatments but birds fed diets containing antibiotic had the lowest FCR (P<0.05). None of the immune related parameters tested differed significantly among experimental treatments (P>0.05). Thyme powder at 10 g/kg level significantly (P<0.05) increased HDL-cholesterol concentration but protein, albumin, triglyceride, total and LDL cholesterol concen-trations were not influenced. Treatments also failed to induce any statistical impacts on hematological parameters of broilers including red and white blood cell count, hemoglobin and hematocrit values. The obtained results suggest that supplementing broilers’ diet with 5 g/kg thyme can indicate favorable influences of antibiotic growth promoter on performance without any detrimental impacts on immune responses and blood parameters.

Key words: Broiler, thyme, growth performance, immunity, serum biochemistry, hematology.

Abbreviation

HDL, High-density lipoprotein; LDL, low-density lipoprotein; RBC,red blood cell; WBC, white blood cell; Hb, hemoglobin; FCR, feed conversion rate;HMG-CoA, 3-hydroxy-3-methylglutaryl-coenzyme A; SRBC, Sheep red blood cell.