Effect of mastitis on raw milk compositional quality

ABSTRACT

In this study, we investigated the impact of mastitisinfection on the quality of milk composition in small-scaledairy bovine herds. The purpose of this study was to finda milk quality somatic cell count (SCC) standard thatcould be used as an integral component of a controlprogram. In all, 396 quarter milk samples from lactatingcross-bred cows (Holstein & Zebu) were analyzed; 56% ofthese quarters were experiencing intramammary infection,with an overall mean SCC of 5.46x10(5)+/-2.30x10(4)cells/ml. Infected quarters had significantly (p<0.05) highermean SCC levels (6.19x10(5)+/-4.40x10(4)cells/ml) comparedto healthy quarters (2.65x10(5)+/- 2.40x10(4)cells/ml). Inhigh SCC milk and infected quarters, the concentrationsof non-casein fractions, sodium, chloride, and free fattyacid were higher (p<0.05), while the casein content,lactose, casein-to-total protein, potassium, and calciumwere lower (p<0.05) compared to normal quarters. Thesefindings suggest a mean SCC threshold limit of 5.46x10(5)cells/ml for the region. It was concluded that the resultscould be used to propose a milk quality SCC standard thatcan be used as an integral component of a control program.