MICROBIOLOGICAL QUALITY OF RAW MILK IN BHUTAN

Abstract

A two-year longitudinal study was undertaken with the objective to establish a bench-mark for microbiological quality of milk in Bhutan. A total of 2191 milk samples were collected from nine functional and relatively more organized farmers’ dairy groups located in eight different districts and two government dairy farms. Samples were aseptically collected and subjected to rapid field mastitis tests, followed by laboratory culture, isolation, identification and further characterization. The study revealed that 89% of the samples had udder infection, with prevalence rate of sub[1]clinical and clinical mastitis at 67% and 20.7%, respectively. This indicates contamination of raw milk with both contagious and environmental pathogens. A variety of pathogenic organisms of 18 different groups comprising 944 isolates were isolated and identified. There was a significant prevalence of anti-microbial resistance for milk borne pathogens. There was also a significant seasonal variation in the microbiological quality of raw milk. Based on this study, there is a need to improve the microbiological quality of milk through adoption of hygienic milk production techniques and improved udder health control programme.