Assessment of Physicochemical and Microbiological Quality of Jersey Cattle Raw Milk at Different Stages of Lactation

The physico-chemical and micro-biological properties of raw milk from Jersey breed cows at different stages of lactation were investigated. Raw milk samples were collected from twelve Jersey cows at the colostrum, early lactation, mid lactation and late lactation stages, at a commercial feedlot dairy farm located in Edu Local Government Area, Kwara State, Nigeria. The results showed that the Jersey cows raw milk were characterised by high physicochemical qualities. The pH ranged between 5.93 and 7.00. The ranges of specific gravity (1.11), titrable acidity (0.18 to 0.23 % lactic acid), ether extract (4.83 to 6.07 %) and viscosity (175.23 to 243.50 centistrokes) were observed. The Jersey cows raw milk samples were also of good microbiological qualities. Total viable bacteria counts ranged from 1.9 x 103 cfu/ml in the late lactation milk, 2.3 x 102 cfu/ml in the colostrum, 5.0 x 102 cfu/ml in the early lactation milk and 8.6 x 102 cfu/ml in the mid lactation milk. The Bacillus species and Pseudomonas species bacteria were identified. The total viable bacteria counts observed in this study are within the 2.0 x 105 cfu/ml bacterial count of the ISI (International Standards Index) limits for raw milk. There was no coliform organism observed in the colostrum, early lactation and mid lactation milk. Aeromonas species organism with a total coliform count of 2.3 x 102 cfu/ml was observed in the late lactation milk. The value of total coliform counts observed in the current study met required standard. Rhizopus species and Aspergillus species fungi with total fungal counts of between 1.3 x 102 cfu/ml (colostrum), 2.5 x 103 cfu/ml (early lactation), 3.2 x103 cfu/ml (late lactation) and 3.3 x 103 cfu/ml (mid lactation) milk were observed. It can be concluded that the raw Jersey cattle milk samples (collected from the commercial dairy farm in Edu Local Government Area, Kwara state, Nigeria) at the different stages of lactation were of good physicochemical and microbiological qualities and this may be due to maintaining better hygiene conditions.