Bacterial Counts of Unprocessed Bovine Milk Produced by Small Scale Farmers in Ndivisi Ward, Bungoma County, Kenya

Aim: This study was conducted to determine the bacterial counts in unprocessed bovine milk among different sub locations, milk sources and replicates in different months having different seasons.

Study Design: A cross-sectional study design was employed whereby milk samples from randomly selected production points and outlets were collected.

Place and Duration of Study: The study was carried out in Ndivisi ward, Bungoma County, Kenya, between October 2016 to December 2016.

Methodology: 100µl of each sample was placed onto plates with plate count agar (PCA) using pour plate method to determine bacterial counts. Bacterial communities were isolated from the samples cultured on MacConkey agar and Blood agar supplemented with 5% sheep blood which were later enriched and purified on nutrient agar. The bacteriological status of milk was assessed by total plate count, isolation and identification of pathogenic bacteria. Data on bacteriological quality of milk was summarized using statistical analysis; means, standard deviation and variance. The difference in bacterial counts (CFU/ml) between sub locations, sources of milk and replicates in the study was assessed using analysis of variance (ANOVA). Statistical significance was set at p=0.05 using a computer package, SPSS software version 20.0.

Results: A total 486 were collected but only 235 samples (48.4%) were contaminated. Staphylococcus aureus was (28.1%) in abundance, pathogenic Escherichia coli (21.7%), pseudomonas aeruginosa (19.1%) Bacillus subtilis (11.5%), Citrobacter freundii (10.2%), and Klebsiella pnemoniae (9.4%) and they cause mastitis, food poisoning and diarrhoea. The presence of bacteria in milk in Ndivisi ward is associated with poor milk handling practices and contamination.

Conclusion: Milk in Ndivisi ward is contaminated hence not suitable for human consumption. High bacterial counts at production (single animal) are the main cause of mastitis in dairy animals.