ABSTRACT:The aim of this study was to determine the effect of colostrum quality and composition on passive calf immunity in primiparous and multiparous dairy cows. Twenty-four primiparous and 24 multiparous dairy cows were used in this study. Calves born from primiparous dairy cows comprised the first group and calves born from multiparous dairy cows constituted the second group. After birth, colostrum samples were immediately taken from dairy cows. Venous blood samples were collected from the calves before the first colostrum intake and on the 2 nd , 7 th , 14 th and 28 th days after the first colostrum intake. Blood and colostrum samples were analysed for biochemical parameters, immunoglobulin and mineral levels. Fat and crude protein levels in colostrum were determined using the Gerber and Kjeldahl methods, respectively. Immunoglobulin levels in the colostrum of multiparous cows were significantly (P < 0.05) higher compared to primiparous cows while fat ratio, LDH activity, Ca, Mg, P and K levels were lower. There was a positive correlation among colostrum immunoglobulin, gamma-glutamyltransferase, crude protein and total protein. Serum immunoglobulin, total protein, globulin and gamma-glutamyltransferase activity in all calves were increased following the colostrum feeding. However, the serum immunoglobulin, total protein, globulin and gamma-glutamyltransferase levels in the second group of calves were higher than those of the first group of calves. There was a positive correlation among serum immunoglobulin, gamma-glutamyltransferase, globulin and total protein. Fe concentrations in all calves decreased over the course of 14 days and were lower in the second group of calves compared to the first group. In conclusion, the results of this study show that the colostrum quality of multiparous cows was better than that of primiparous cows. Colostrum crude protein, total protein, gamma-glutamyltransferase along with colostrum immunoglobulin might be used to determine colostrum quality. Serum immunoglobulin, total protein, globulin and gamma-glutamyltransferase activities could be used to determine the passive transfer status of calves.