ORIGINAL ARTICLE Growth performance, carcass quality, biochemical and haematological traits and immune response of growing rabbits as affected by different growth promoters Y. A. Attia 1,2 , A. M. El-Hanoun 3 , F. Bovera 4 , G. Monastra 4 , W. S. El-Tahawy 2 and H. I. Habiba 2 1 Arid Land Agriculture Department, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, Saudi Arabia, 2 Department of Animal and Poultry Production, Faculty of Agriculture, Damanhour University, Damanhour, Egypt, 3 Animal Production Research Institute, ARC. Ministry of Agriculture, Giza, Egypt, and 4 Department of Veterinary Medicine and Animal Science, University of Napoli Federico II, Napoli, Italy Summary The aim of the article was to study the effect of different growth promoters on growth performance, carcass qual- ity, biochemical and haematological traits and immune response of growing rabbits. A total number of 105 male growing NZW rabbits during 35–91 days of age were randomly distributed among 7 groups fed the same basal diet and submitted to different dietary treatments: the first group was unsupplemented and used as control; the other groups were supplemented respectively with bee pollen and/or propolis at 200 mg/kg BW of each and inu- lin and/or mannanoligosaccharides (MOS) at 35 mg/kg BW of each. Body weight gain, daily feed intake, feed conversion ratio (FCR), biochemical and haematological blood parameters, carcass characteristics, histological studies of ileum and spleen and economical efficiency were measured. Bee pollen administered alone or with propolis significantly (p < 0.01) the body weight gain and improved FCR in respect of the control group. Inulin with MOS significantly improved just FCR than the control group. Bee pollen with propolis and MOS supple- mented-groups resulted in significantly higher (7.96 and 8.41% respectively) white blood cells compared to the control group. Plasma total cholesterol was significantly higher for the MOS group in respect of the control, bee pollen, inulin and inulin with MOS supplemented-groups. Propolis resulted in significantly higher dressed car- cass percentage than the control group and higher carcass index than only bee pollen with propolis supple- mented-group. Bee pollen, in particular if in combination with propolis, could be used as a supplement in the growing rabbits during days 35–91 of age with positive effects on growth rate and feed conversion ratio. Keywords rabbits, growth performance, bee pollen, propolis, immune response Correspondence Fulvia Bovera, Department of Veterinary Medicine and Animal Science, University of Napoli Federico II, Via F. Delpino, 1, 80137 Napoli, Italy. Tel.: +39 081 2536497; Fax: +39 081 292981; E-mail: bovera@unina.it Received: 13 September 2012; accepted: 16 January 2013 Introduction For several decades, antibiotics in sub-therapeutic doses have been used in animal production to improve animal welfare and performance and to reduce medication costs. However, there are increas- ing concerns about the risk of developing cross- resistance and multiple-antibiotic resistance in pathogenic bacteria both in man and in livestock. The European Union has banned all of in-feed use of antibiotics since 2006, and the use of antibiotics in feed is being consid- ered for elimination (or intense regulation) in other parts of the world. In rabbit production, the ban of antibiotic growth promoters poses a serious challenge as because of the very complex and peculiar digestion (caecotrophy, microbial fermentation), the rabbit is susceptible to enteric diseases, particularly after weaning. For this reason, several studies have been conducted to find alternatives to replace dietary antibiotics (Eiben et al., 2008). Bee pollen enhances immunizing function of poul- try, promotes animal growth, protects intestinal tract health and improves animal products quality and security (Liu et al., 2010). Also, bee pollen has ability to protect kidney, and bee pollen and propolis can decrease the level of triglycerides, cholesterol, creati- nine and blood urea nitrogen in rats (Hu et al., 2003). Propolis is a natural additive with natural antibiotic properties and may have potential in improving Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH 1 DOI: 10.1111/jpn.12056