Assessment of microbiological status and presence of antibiotic residues in cow milk produced in Bagamoyo and Kisarawe districts, Tanzania

Abstract

A cross-sectional study was conducted to assess milk quality supplied to collection centres in Bagamoyo and Kisarawe districts in Pwani region between February and May 2012. A total of 186 milk samples were collected during starting of the rainy season (February to March, n=95) and towards the end of the rainy season (April to May, n=91). Total bacterial count (TBC) and Coliform counts (TCC) were established and used as indicators of microbial contamination of the milk. Presence of antibiotic residues was also determined qualitatively using the Delvotest kit. Questionnaires were administered to 93 suppliers of milk sold at the collection centres to identify management factors which may influence milk quality. Overall results indicated that ony10.2% and 14% of the tested milk samples would qualify as grade I milk based on TBC and TCC, respectively, both parameters being significantly different between districts and between start and end of the rainy season. Least Square Means indicated source of water used for sanitation to have significant effect on TBC and type of storage containers to have significant effect on TCC. Twenty one percent of the milk samples tested had antibiotic residues and
there was no significant difference between districts and seasons. It is concluded that milk supplied to the collection centres in Pwani region is of poor quality and could pose public health risks to consumers. Interventions to address these problems are required.

Key words: Antibiotic residues, Total bacterial counts, Coliform counts, Public health significance