Evaluation Of Chemical And Bacteriological Quality Of Raw Milk From Neudamm Dairy Farm In Namibia

The quality of raw milk obtained from Friesian (Holstein) cows at Neudamm dairy farm was investigated after the quality issue was raised by some milk consumers at the University of Namibia, Neudamm campus. Some consumers complained about the short shelf-life of the milk as it is sold untreated due to lack of processing facilities at the centre. Others were worried of their health as they usually ferment raw milk for home use. In addition, the farm has no proper records of the quality of its milk for dairy herd management. The Department of Food Science and Technology of the University of Namibia, Neudamm campus took an initiative to identify the cause of the problems and the consumers’ health concerns in order to come up with some remedial solutions. Samples for proximate composition and microbiological analyses were collected during the winter and summer seasons and from morning and evenings’ milk at Neudamm Dairy Farm for chemical and microbial analyses. The quality of raw milk sold to staff members was evaluated and the data were used to assist the farm with dairy herd management programme and quality assurance. The mean temperatures, chemical, microbiology and acidity tests were determined. The temperatures ranged from 35 to 37oC. Titratable acidity expressed as lactic acid had a mean of 0.18%, total protein 3.2%, fat 3.63%, total solids (TS) 12.33%; solids-not-fat (SNF) 8.7% and pH varied from 6.0 to 6.7. There were some variations in composition between winter and summer and between morning and evening milk, which are well known and significant at p<0.05. Furthermore, large variations were noted in microbiological composition of raw milk with total aerobic counts ranging from 7.8x10⁴ - 1.3x10⁶ cfu/ml, coliforms from 2.4x10² - 2.3x10³ cfu/ml and lactic acid bacteria (LAB) from 1.2x10³ - 2.6x10⁵ cfu/ml. Yeasts and moulds were less than 100 cfu/ml in all samples analyzed. From the bacteriological and chemical analysis, it is concluded that the university farm needs a processing unit to control the quality of milk, add value and for training purpose.