Prevalence and identification of antibiotic residues in dairy cow’s bulk tank milk produced in Lebanon

This research was aiming to evaluate in Lebanon the prudent use of veterinary antibiotics and the prevalence of antibiotic residues in raw cow’s milk. A first survey concerning antibiotics and their utilization was carried out involving 100 farmers, developing a specific questionnaire. The results have shown that most of the Lebanese dairy farmers have a very low knowledge level about antibiotics. A second study to investigate the occurrence of veterinary drug residues in dairy raw milk produced in the seven Lebanese Governorates was also carried out. A total of 1020 raw milk samples that covers big and medium size dairy farms and dairy raw milk collection centers were collected. Samples were tested using a microbiological test for inhibitors, lateral flow test for residues and high-performance liquid chromatography (HPLC) test. Results show that using microbiological test, 22% (220) out of 1020 collected samples were double positive for inhibitors. HPLC-DAD test results showed that out of 220 double positive samples tested with microbiological test, 143 (65%) samples were contaminated with penicillin G (53.6%), tetracycline (23.1%) and florfenicol (22.7%). Charm® TRIO and AMPH tests revealed that out of arbitrary 95 positive samples tested using HPLC, 92 samples were contaminated with penicillin G (62.1%), tetracycline (43.2%), amphenicol (40%) and sulfa drugs (32.6%).