Smallholder dairy processing in Zimbabwe: hygienic practices during milking and the microbiological quality of the milk at the farm and on delivery

The hygiene practices during milking and the microbiological quality of milk at the farm and on delivery at three smallholder dairies in Zimbabwe were studied. Petrifilm™ was used for the determination of Escherichia coli, coliforms and aerobic mesophilic counts (AMC). Using AMC Petrifilms™ as contact plates, 83% (n=66) of the utensils used for milking had >300 cfu per 20 cm². Of milk samples at the farm, 95% (n=24) had E. coli counts $\text{<10}{}^1\text{cfu}\text{ml}{}^{\mathrm{-1}}$, and all had $\text{AMC}\text{<10}{}^5\text{cfu}\text{ml}{}^{\mathrm{-1}}$. On delivery at the dairy, the proportion of milk samples with $\text{AMC}\text{>10}{}^5\text{cfu}\text{ml}{}^{\mathrm{-1}}$ was 28%. The increase in number of microorganisms in the milk was correlated with factors which would increase delivery time.