Bacteriological Quality Assessment of Milk in College of Veterinary Medicine (Cvm) Dairy Farm and Kalamino Dairy Farm in Mekelle, Tigray, Ethiopia

Abstract

Milk is an important source of nutrients to human and animals, but due to its high-water activity and nutritional value, it serves as an excellent medium for growth of many kinds of microorganisms under suitable conditions. The present cross-sectional study was conducted to assess hygienic practices, determination of bacterial quality of milk and isolation and identification of bacterial pathogens in milk at each critical control point throughout the value chain in MU-CVM and Kalamino dairy farms in Mekelle from August to November 2017. A total of 40 respondents were interviewed and subsequently, 84 milk samples were collected for laboratory analysis including bacterial load assessment and isolation and identification of bacteria. Total bacterial plate counts from milk were conducted. Isolation and identification of the bacteria in the milk was also conducted following standard methods. Results showed that, attendants of study dairy farms, managing their cattle in moderate hygienic environments and practicing intensive farming system. The mean total bacterial plate counts of raw milk samples analyzed were 2.15x108 cfu/ml (udder), 3.4x108 cfu/ml (storage area in the farm) and 5.96x108cfu/ml (distribution center milk container). The increment of both counts at each critical control points was observed statistically significant (P=0.000). However, there was no significant variation between the two farms (P= 0.074) in the mean total bacterial count. About 26.7%, 50%and 62.5% from teat, storage area in the farm and distribution center milk containers, respectively at MU-CVM and 40.9% from the teat, 62.5% from milk storage area and 75% from distribution center milk containers, respectively at Kalamino dairy farm were graded of poor quality. In the course of this study, the frequent bacterial pathogens isolated from raw milk samples taken from different critical points include: E. coli, S. aureus and Streptococcus spp. From the result there were hygienic practices in the study farms, but the quality of milk used for human consumption area was found inferior quality according the standard level. Thus, it is important practice proper and restricts hygienic practices, proper transportation and storage and reducing the milk storage time, raising the awareness of dairy workers to enhance the quality of milk used for human consumption. Keywords: Bacterial load; Bacterial isolation; Critical control point; Dairy farms; Milk