Epidemiological assessment of antibiotic residues in dairy farm milk and farm waste and water in northern India.

Antibiotics are frequently used in the dairy sector for prophylactic uses along with therapeutic purposes. Throughout the globe, antibiotic resistance has turned out as one of the greatest public health issue with greater concern in developing countries, such as India. On the matrix wise comparison of the study, slurry samples in all three farming systems show the highest proportion of positive samples. Out of 153 slurry samples, 15.6% samples showed the presence of antibiotic residues. Eighteen milk samples (11.7%) showed the presence of residues following this trend. Only one sample (0.65%) was positive of animal drinking water in the study. None of the targeted residues were found in any sample of human drinking water. The four pond water samples showed the prevalence of residues of oxytetracycline (2 samples) and enrofloxacin (2 samples). Medium size farms (10-30 animals) comprised comparative higher levels than small (< 10) and large farms (> 30). The excretion mass modelling of antibiotics released in the environment indicated 8325.41 kg of oxytetracycline and 12,498.89 kg of enrofloxacin per year. The study helps in providing understanding in the relation between antibiotics usage and dissemination of their residues to the environment which may result in likely ecotoxicological consequences.