Iranian Journal of Veterinary Medicine 195 IJVM (2015), 9(3): Comparison of broiler performance, blood biochemistry, hema- tology and immune response when feed diets were supplemented with ginger essential oils or mannan-oligosaccharide Ghasemi, H.A. 1 , Taherpour, K. 2* 1 Department of Animal Sciences, Faculty of Agriculture and Natural Resources, Arak University, Arak, Iran 2 Department of Animal Sciences, Faculty of Agriculture, Ilam University, Ilam, Iran Abstract: BACKGROUND: Nutritional strategies targeting improvement of poultry performance and disease prevention are currently being developed and in this respect the dietary intake of spiced essential oils and pre-biotics in raising broilers is receiving at- tention. OBJECTIVES: This study was conducted to compare the effects of diet containing ginger essential oils (GEO) and man- nan-oligosaccharide (MOS) on growth performance, biochem- ical and hematological parameters, lymphoid organ weights and antibody response of broilers. METHODS: A total of 375 day old male broiler chicks were randomly assigned to fve treatments (fve replicates per treatment). Dietary treatments included basal diet as control, GEO-supplemented diets with inclusion levels of 50 (GEO1), 100 (GEO2) or 200 (GEO3) mg/kg, and MOS supplemented diet with an inclusion level of 2 g/kg. RESULTS: The birds fed on MOS and GEO3 diets exhib- ited better feed conversion ratio and higher body weight gain from 1 to 42 day of age compared with control birds (p<0.05). Serum low density lipoprotein cholesterol level in the MOS, GEO2 or GEO3 groups was lower than that of the control group (p<0.05). Serum cholesterol level was also lower in the GEO2 and MOS groups (p<0.05). Feeding on GEO3 and MOS diets signifcantly increased relative bursa weight and second- ary antibody titer against infectious bursal disease (IBD) and infectious bronchitis (IB) vaccines as compared with control diet (p<0.05). CONCLUSIONS: The results showed that higher level of GEO (200 g/kg) similar to MOS supplementation, im- proved feed effciency and immune response. This could meet consumers’ demand for a safe feed additive. Key words: ginger essential oils, prebiotic, performance, immune response, broilers Correspondence Taherpour, K. Department of Animal Sciences, Faculty of Agriculture, Ilam University, Ilam, Iran Tel: +98(841) 2226903 Fax: +98(841) 2227015 Email: kamran_taherpour@yahoo. com Received: 7 April 2015 Accepted: 13 July 2015 Introduction The main objective of poultry farming is to ensure high growth performance and good quality of poultry products, which are suit- able for further processing. With increasing commercialization and intensifcation in poul- try production, the economic implications of poultry diseases are becoming more important because of the upsurge in stressful conditions (Castanon, 2007). Under such conditions, uti- lization of suitable additives including, prebi- otics and more recently herb and spice prod- ucts in the poultry feed to improve growth and 195-205