Physical properties of mammary secretions in relation to chemical changes during transition from colostrum to milk.

摘要: We examined the physical and chemical changes in milk during early lactation, how these were affected by leaving one quarter unmilked either first or second milking, with purpose of discriminating between colostrum normal milk. Milk samples collected from each 17 cows 5 d after calving then about 7 14d. Samples analysed for somatic cell count (SCC), fat, protein, casein, lactose, IgG1, colour, plasmin, pH coagulation properties. Large variations occurred both properties throughout study period. Within six milkings, concentration casein decreased 60%, IgG1 94%, lactose increased 34%. At milking number 6, rennet time was lowest curd firmness highest. The 6.4 to 6.7 over period experiment, colour changed yellow (reddish) white. Coagulation fell within range five milkings. Measurement density appeared be a potential method detection unsuitable dairy factory. Effects omitting differed components, but seemed little importance