Studies of milk freezing point as a measure of standardization

Abstract

Trials were carried out on ITG farms and on purchasing area of the individual sector under conditions of Pomoravlje. Milk samples were directly taken from stables and from entire milk collected in dairy from the two ITG farms as well as that purchased from the cooperatives.

Freezing point of the whole natural milk sampled directly from the Simmental and Domestic Spotted cows ‘udder was tested, followed by that of the milk collected from ITG farms and that of the cooperatives. In addition, the total milk of the Simmental and Domestic Spotted cows was supplemented with 5, 10, 15 and 20% water in order to determine milk freezing points with these dilutions. The results indicated the freezing point of the Simmental cows total milk to amount to 0.5422 °C and that with domestic spotted ones to - 0.5419 °C. Water added to the milk of Simmental and Domestic cows brought about a higher freezing point which approximated zero point per each per cent of water added on an average by -0.0060 °C in Simmental and by -0.0055 °C in domestic spotted cows.

In the milk collected from the individual sector, milk freezing point averaged -0.5195 °C, which was even higher, i.e. very much close to the zero point compared to the total and sum milk from the farms.

Testing the differences between the mean values of freezing points of the total milk taken from the Simmental and domestic spotted cows directly from udder in the stable, and from those of the total milk from ITG farms and cooperatives, taken on the dairy loading platform,e nabled us to conclude that the milk from the farms had a standard quality, whereas 5% water was added to the total one purchased from cooperatives.