S. Ghazi - Department of Animal Science, Faculty of Agriculture, Razi University, Kermanshah, Iran.
R. Mahdavi - Department of Animal Science, Faculty of Agriculture, Razi University, Kermanshah, Iran.
A. Naseri - Department of Basic Sciences, Faculty of Veterinary Medicine, Razi University, Kermanshah, Iran.
M. Habibian - Department of Animal Science, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran.

This study was carried out to evaluate the effects of Satureja khuzistanica essential oils (SKEO) on performance, serum metabolites and differential counts of white blood cells in broiler chickens. A total of 280 one-day-old straight-run Cobb 500 broiler chickens were allocated into seven treatment groups with four replicates of 10 birds each from day 1 to 42 of age. The birds were continuously given drinking water supplemented with 0 (Control–), 100, 200, 300, 400 and 500 mg/L SKEO or 1,000 mg/L Tween-80 (control+) as seven experimental treatments. During overall period (1 to 42 days) of the study, broilers received water supplemented with 300, 400 and 500 mg/L SKEO consumed less (P < 0.05) feed compared with those given water supplemented with 100 mg/L SKEO. However, feed intake for the control broilers was intermediate and was not statistically different (P > 0.05) from either of the groups. Broilers received water supplemented with 300 mg/kg SKEO had lower (P < 0.05) weight gain compared with the control broilers, while feed conversion ratio was higher (P < 0.05) in broilers received water supplemented with 100 mg/kg SKEO compared with the control broilers. The serum concentrations of glucose, triglycerides, and total cholesterol were not affected (P > 0.05) by treatments at days 21 and 42 of age. Similarly, water supplementation with SKEO had no effect on differential counts of white blood cells and heterophil to lymphocyte (H/L) ratio at days 21 and 42 of age. Overall results of the present study showed that drinking water supplementation with SKEO had no beneficial effect on growth performance, serum metabolite concentrations and differential counts of white blood cells in broiler chickens and water supplementation with 100 and 300 mg/L SKEO decreased broiler growth performance.

Broilers, Growth Performance, Satureja khuzistanica, serum metabolites, white blood cells