Microbiological Quality of Raw Cow Milk across the Milk Supply Chain in Eastern Ethiopia

Abstract

The risk of milk contamination with spoilage and pathogenic microorganisms is high for milk produced in developing countries like Ethiopia especially in lowland region as their milk production practices is traditional type which lack appropriate hygienic control. To protect the raw cow milk from spoilage loss and consumers from milk born public health risk, the availability of documented information on the microbiological quality of raw milk across the milk supply chain is critically important as such information may be important for different organization to undertake relevant development intervention on hygienic practices essential for safe milk production and handling. This study was, therefore, conducted to determine the microbiological quality of informally marketed raw cow milk across the milk supply chain in eastern Ethiopia. A total of 360 pooled raw cow milk samples (each with a volume of 450 mL) were collected from udders and milk handling equipment of producers in rural areas of Babile district; from the equipment of collectors/transporters in Harar and Dire Dawa towns as well as from the equipment of vendors and consumer at Babile, Harar and Dire Dawa towns during February 2014 to January 2015. The milk samples were subjected to laboratory analyses to evaluate total aerobic mesophilic bacteria count (TAMBC), total coliform count (TCC), yeast count (YC) and mold count (MC) in the laboratory to determine the microbiological quality of the milk. Mean TAMBC, TCC, YC and MC for raw cow milk samples collected directly from the udders were 6.02±0.14, 4.23±0.12, 2.57±0.10 and 2.67±0.10 log₁₀ cfu mL^-1, respectively. The values for the samples collected from the equipment of producers upon arrival at their selling points were 7.17±0.14, 5.86±0.12, 3.46±0.10 and 3.70±0.10 log₁₀ cfu mL^-1 for TAMBC, TCC, YC and MC, respectively. Mean TAMBC, TCC, YC and MC for samples collected from the equipment of collectors/transporters were 7.96±0.10, 6.49±0.07, 3.99±0.07 and 4.37±0.07 log₁₀ cfu mL^-1, respectively. The microbial counts for samples collected from the equipment of vendors were 8.78±0.08, 7.32±0.07, 4.98±0.06 and 5.04±0.07 log₁₀ cfu mL^-1 for TAMBC, TCC, YC and MC, respectively. The values for samples collected from equipment of consumers were 8.82±0.08, 7.37±0.07, 5.10±0.06 and 5.11±0.07 log₁₀ cfu mL^-1 for TAMBC, TCC, YC and MC, respectively. It could be concluded that raw cow milk samples collected from all towns and milk source were severely contaminated with aerobic mesophilic and coliform bacteria, yeast and molds, with loads exceeding the respective acceptable limits.

Keywords: Dairy production system; Herd size; Microbiological quality; Milk supply chain, Raw cow milk