Anotace:
This study was aimed at the evaluation of changes in the concentrations of selected blood serum proteins in calves during the first three months of life, including precolostral, colostral, milk, transitional and solid feeding period. Nine clinically healthy calves were used in this study. The first blood sampling was performed before the colostrum intake (day 0) and then at 1, 2, 7, 14, 30, 60, and 90 days of age. Blood serum was analyzed for the concentrations of α1-fetoprotein, prealbumin, transferrin, and lactoferrin. The results showed significant changes in the serum concentrations of all the evaluated proteins in calves during the first three months of life (P < 0.01 and P < 0.001). At birth, the mean concentration of α1-fetoprotein was low and increased more than × 8 at one day after colostrum intake, then a gradual decrease was found up to day 30 of life. Similar tendency was observed in the concentrations of prealbumin and lactoferrin. While the concentrations of prealbumin increased approximately × 3.5 at one day after colostrum intake, the serum lactoferrin values showed approximately 1.5-fold increase. A subsequent gradual decrease from the 2nd day of life was found for both prealbumin and lactoferrin. In the concentrations of transferrin, a significant increase was observed on day 7 (P < 0.05). The highest values were found at the age of 14 and 30 days. These results suggest that concentrations of these proteins in calves are markedly altered during the postnatal period, which should be taken into consideration for their precise interpretation in young animals.