Impact of applying hygienic practices at farm on bacteriological quality of raw milk

Abstract

Aim: The present study was carried out to explore the potential source of contamination and the efficacy of different washing practices towards quality milk production. Materials and Methods: Probable sources of contamination viz. stored water, potable water, milker's hands, milking pail, udder of individual buffalo and milk cans were subjected to different types of bacterial counts before the actual experiment to start. Twenty milch buffaloes thereafter were divided randomly into four treatment groups where washing was performed in each step viz. milker hands, udder of individual buffalo, milking pail and milk cans before milking either with water (T0: stored water, T1: potable water) or sanitizers (T2: 200 ppm chlorine solution, T3: 50 ppm iodophore solution) for 60 days. Bacterial counts again were performed for last 5 alternate days for all the sources involved along with the microbial load of raw milk. Data obtained were subjected to standard statistical analysis. Results: It was found that for all bacterial count stored water contributed significantly higher as compared to the potable water. Among the other potential sources of contamination (log/6 cm2), standard plate count (SPC) and coliform count were significantly highest for milking pail (6.73±0.02) and udder of milch buffaloes (3.77±0.12), respectively, while for Staphylococci count both milking pail (3.24±0.02) and milking can (3.22±0.04) were contributed maximally (p<0.05) than others. Washing with stored water contributed significantly (p<0.05) more microbial load from all possible sources of contamination and too reflected on milk quality (SPC: 7.87±0.04, coliform: 4.06±0.46 and Staphylococci: 3.41±0.01) than the other washing treatments, which are followed by washing with potable water. Both the sanitizers were significantly better than the washing with the water but remained statistically similar (p>0.05) for most of the parameters, even for the raw milk quality. Conclusion: Study revealed that milker hands, milking pails, udder of animals, milk cans and stored water used for washing of equipment are the potential source of contamination in raw milk. These were counted as critical point which needs attention for the production of high-quality milk. Potable water was found to be better than stored water. The use of either chlorine 200 ppm and iodophor 50 ppm is highly effective in reducing the bacterial population for quality milk production.