Assessment of bacterial contamination and milk handling practices along the raw milk market chain in the north-western region of Rwanda

Abstract

This study was conducted to assess raw milk bacterial loads and micro-organisms associated with milk handling practices and raw milk chain in the North-western region of Rwanda. A multistage sampling method was used to collect sixty-seven raw milk samples that were analyzed for milk quality at four stages of the raw milk chain: dairy farmers, milk hawkers, milk collection centres (MCC) and milk kiosks. Total bacterial counts (TBC) at different stages of the chain were determined and microorganisms were isolated. A questionnaire was distributed to gather information on factors and milk handling practices that influence milk quality at farm level. The study revealed a TBC mean values of 1.2 × 106 CFU/ml (dairy farmers), 2.6 × 107 CFU/ml (milk hawkers), 1.5 × 106 CFU/ml (MCC) and 6.9 × 106 CFU/ml (kiosks/restaurants). The prevalent micro-organisms were: Escherichia coli (E. coli), 26.9%; Salmonella spp., 16.4%; Streptococcus spp., 16.4%; coagulase- negative staphylococci (CNS), 14.9%. Bacterial load was highly associated with containers used for milk transport, cleaning time of milk containers and source of water used to clean containers. It is, therefore, highly recommended that all concerned parties in the raw milk value chain improve their milk handling and storage practices.   Key words: Bacterial contamination, milk handling, milk quality, north-western Rwanda, raw milk.