STUDY ON CHEMICAL AND BIOLOGICAL PARAMETERS OF COLOSTRUM IN ROMANIAN BLACK AND WHITE COWS

The aim of the paper was to evaluate the colostrum quality and changes in composition during the first seven days postpartum. Researches were carried out on five Romanian Black and White multiparous cows. Samples of colostrum and transition milk were collected at calving and at 6-hour interval for seven days. Samples were analyzed for chemical composition using an infrared spectrometer (fat, protein, lactose and solids non-fat), for somatic cell count using a viscosimeter, for density using a desimeter, for total bacteria count using the classic incubation on Petri dish, and for immunoglobulin concentration using a colostrometer. For study the evolution of the colostrum composition Wood incomplete gamma function was employed (y=abxe(-cx)). Results showed a dramatic change in colostrum yield and composition from the first milking right after calving until the next milking occurred at 6-hour interval. Yield was very low in the first milking (0.9 kg) and increased rapidly with each milking, reaching 11.2 kg in the seventh day postpartum. In the first colostrum the concentrations of milk fat, protein and total solids were high (11.56%, 17.73% and 32.08%, respectively) and were almost half in the second milking, after 6 hours. Lactose concentration was low at the beginning (1.89%) and increased slowly until the seventh day postpartum to 4.39%. Density was as high as 1.74 kg/liter in the first colostrum and decreased rapidly at 1.49 kg/liter. In the seventh day the density was 1.029 kg/liter. Immunoglobulin content had an atypical evolution. It was low in the first colostrum (34.48 mg/ml) and the highest in the second milking (43.66 mg/ml). After that it was decreasing until the end of experiment. Somatic cell count and total bacteria count were high in the first milking (1,575,488 cells/ml and 46,834 cfu/ml, respectively) and decreased after that