One hundred and two Friesian cows and their offspring were used to identify factors associated with colostrum quality, risk factors associated with failure of passive transfer of immunity, and to monitor changes in serum IgG and total protein (TP) concentrations during the first week of age.The time from calving until the first milking, dam parity, the calving date, and calf gender were recorded.The volume, chemical composition of colostrum, and IgG levels were determined. Blood samples of each calf were collected daily until 7 days of age. Concentrations of IgG and TP in blood serum were measured. Significantly higher concentrations of TP and total solid and the percentage of cows that had IgG ≥50 g/L in colostrum were recorded in the winter season, fourth or greater lactation, and when cows were milked within two hours after calving.To assess the passive transfer of immunity for calves, both the IgG and TP concentrations were measured in serum at 24 h after colostrum feeding. The percentage of calves affected by the failure of passive transfer of immunity was 29.41%. Significantly higher concentrations of IgG and TP were recorded in the serum of Friesian calves that received ≥2Lfrom colostrum containing IgG ≥50 g/Lat first feeding within2h after birth, as wellas calves born during the winter season or their dams of the second or more parity. The concentrations of serum IgG and TP in the calves showed no significant changes during the first week of age. They showed the highest values at 24 h after colostrum feeding (24.46 g/L and 6.09±1.44 g/dL, respectively) .Thereafter,the values insignificantly decreased gradually until the end of the first week of age. Concentrations of serum IgG and TP measured from day 2 to 7 were highly correlated with the value recorded 24 h after colostrum feeding (r ≥0.905 and r ≥0.765, respectively). Values of serum IgG and TP concentrations were highly correlated (r= 0.842;P <0.0001) during the first week of age. This indicates that determination of serum TP concentration up to day 7 can provide a reliable estimate of passive transfer as analternative method for rapid and simple monitoring of passive transfer in calves.