DETERMINATION OF MILK-BORNE PUBLIC HEALTH HAZARDS IN RAW MILK FROM RETAIL OUTLETS AROUND MANZINI CITY

Abstract

Following milk price deregulation in the late 1990’s, the number of dairy farmers selling raw milk direct to consumers increased remarkably. The public health safety of such milk has not been ascertained. This study was carried out to determine milk-borne public health hazards in raw milk sold by retail outlets around Manzini. Milk samples were obtained from seven raw milk retail outlets around the Manzini- Malkerns corridor. Total bacterial counts, psychrotrophic bacterial counts, coliform counts, Escherichia coli counts, yeast and moulds counts were determined. Milk samples were also tested for milk freshness, composition, adulteration and presence of antimicrobial substances. The overall results obtained revealed that raw milk was of poor hygienic quality and could be a health hazard to the public. Milk samples from all the retail outlets did not meet the international standards for acceptable hygienic quality. Total bacterial counts reached up to (5.2 x 107 cfu/mL), psychrotrophic bacterial counts reached (1.1 x 107 cfu/mL), coliform counts were (2 x 109 cfu/mL), E. coli counts reached (3.8 x105 cfu/mL) and yeast and moulds counts were (2.7 x 106 cfu/mL). All the raw milk samples had lactic acid above the standard, <0.22 %(v/v) for fresh milk. Storage temperatures from all the milk samples were above the maximum standard temperature (10oC). About 82% of the milk samples tested positive to unacceptable antimicrobial residues sensitivity levels. There was also a big variation in butter fat percentage among samples taken during the study period. Milk from Retailer 2 had specific gravity lower than the minimum level, 1.025g/cm3. This corresponded to at least 5% (v/v) water addition. These results have suggested that poor milk hygienic quality may be attributed to poor cleaning and sanitising of milking and storage equipment, poor storage temperatures, long storage hours of raw milk at the farm, poor routine hygienic practices and ill health of both the milking cows and personnel handling the milk. Variations in butter fat percentages can be attributed to poor agitation in milk shop cooler tanks as most of them had no stirring facilities. Promotion of measures concerning elementary hygiene at farm level and at the market level is highly recommended. Of major importance, efforts must be made to strengthen the country’s quality control system in order to develop a competitive and a sustainable dairy industry.