The Effect of Lactation Number on Physico-Chemical and Microbiological Parameters of Milk from Small and Medium Bovine Farms located in Transilvania Region

Abstract
Milk is a biological fluid where fats are distributed in microglobules (2-10 million/cm3), in an aqueous solution of proteins, carbohydrates and other substances. The main physico-chemical properties of milk are: density, viscosity, specific heat, boiling point, freezing point, pH and total acidity. Microbiological quality is represented by the presence or absence of pathogens or alterations, which can contaminate milk as a raw material. The comparative nutritional and microbiological quality of milk from three counties, from Transilvania Region, were fat percentage, total protein, casein content, lactose, pH, urea, total germ count (TGC) and somatic cell count (SCC). The best percentages of fat were obtained in Bihor County, with mean values of all lactations of 4.00%. This was followed by Hunedoara County with 3.97% and Alba County with 3.95%. The highest protein percentages were obtained in samples collected in Bihor County, with mean values of 3.57%, followed by Hunedoara County with 3.52% and Alba County with 3.51%. Most physicochemical indices fall within the normal limits, unanimously accepted by existing standards, but microbiological indices in some cases do not meet the requirements for the admission of raw milk.