Drug-free chicken meat production: Sh. Rahimi et al. XVII th European Symposium on the Quality of Poultry Meat Doorwerth, The Netherlands, 23-26 May 2005 326 Drug-free chicken meat production SH. RAHIMI*, M.A. KARIMI TORSHIZI, H. POORHASSAN and Z. MOGHADDAM Department of Poultry Science, College of Agriculture, Tarbiat Modarres University, P.O. Box 14115-336, Tehran, Iran *rahimi_s80@yahoo.com Keywords: antibiotic alternatives; probiotics; organic acids; anti-Salmonella antibody; poultry meat Summery Developing antibiotic resistant strains of microorganisms and drug residues in poultry meat, which potentially are dangerous for consumers, cause some deep concerns about use of antibiotics in food production, specially in poultry products. It is well established that application of growth promoting antibiotics will help in productivity and prevention of diseases in broiler farms. Extensive efforts were performed to find safe and effective alternatives for antibiotics. Present study conducted in order to investigate the effects of three antibiotic alternatives in poultry production. I. Lactic acid bacteria probiotics, II. Commercial blend of organic acid salts (Ammonium formate and propionate; Salkil®), and III. Combination of anti-salmonella antibody and a commercial probiotic; (Primalac®). The best performance of broilers in terms of live body weight achieved by using antibiotic (Virginiamycin) as growth promoter, and one of the isolated lactic acid bacteria as probiotic give the highest body weight, followed by antibody + probiotic, antibody and organic acids. Introduction Chicken meat is one of the most common used animal protein sources because of its nutritional value and relative reasonable prices in many countries. Recently problems related to other meats, like as bovine spongiform encephalopathy (BSE), leads to increasing attention to poultry products. In poultry production use of antibiotics for treatment and prevention of diseases and promotion of growth is a common practice. In some countries there is no effective authority responsible for use of animal antibiotics and it is not unusual to see self medication of poultry flocks. Extensive use of antibiotics caused some concerns about development and distribution of antibiotic resistance in animal pathogen microorganisms and consequently possible resistance in human pathogen strains. Drug residues left in edible tissue and environment contamination, which may threat public health is another aspects of this tragedy. Use of antibiotics in food animals is limited to special conditions in many countries, and growth promoter antibiotics (GPA) are prohibited in some countries. In order to decide about ban of GPA in poultry, suitable strategies must be taken. In present study efficiency of three antibiotic replacement methods were compared in separate experiments. Microflora of digestive system plays an important role in colonization resistance against pathogenic agents, while in industry conditions production introduction and development of natural digestive flora starts with delay. In the first experiment probiotics were tested as a potential replacement of GPA, in chicken meat production. Lactic acid bacteria are an important member of natural flora of digestive and reproductive tract of man and animals. It is believed that some lactic acid bacteria act as probiotics. A probiotic is "Live microbial feed supplement which beneficially affects the host animal by improving its intestinal balance" (3). In the second experiment efficiency of a commercial blend of organic acid salts (Salkil®) were examined. Efficiency of combined use of anti- Salmonella IgY produced in present study with probiotics were tested in the third experiment. Materials and methods TRIAL I Initially several lactic acid bacteria were isolated from digestive system of healthy chickens. After verification of their identity by morphological and chemical methods, three isolates (Viz. L1, L2 and L3), were selected based on probiotic criteria, such as pathogen inhibition (2), acid and bile salt tolerance, and hydrophobicity (6). The selected isolates were used as a laboratory made probiotics. At