Blood plasma protein and lipid profile changes in calves during the first week of life

The present study was undertaken to determine blood plasma protein and lipid profile changes in healthy Polish Holstein-Fresian calves of Black-and-White variety. Blood was drawn immediately after birth, before first colostrum intake and at the 3rd, 6th, 12th, 24th, 36th, 48th and 72nd hour of life. Subsequent four blood samples were collected at 24 hour intervals until the 7th day of life. Plasma proteins within the isoelectric point ranging from 3.0 to 10.0 were separated using high resolution two-dimensional electrophoresis. Among the 74 protein spots detected and analyzed, 16 were significantly altered during the first week of life. Differentially expressed spots were excised from the gels and subjected to peptide mass fingerprinting using MALDI-TOF MS. In total, 12 spots were successfully identified, which correspond to three proteins, namely: apolipoprotein A-I, apolipoprotein A-IV and fibrinogen gamma-B chain. A gradual increase in plasma triglyceride, total cholesterol, HDL and LDL cholesterol values was shown during the first seven days of calves life. The lowest concentration of these indicators were observed at birth and was followed by a rapid increase during the first week of postnatal life. These changes appear to be related to the transition in energy sources, from a maternal nutrient supply comprising mainly carbohydrates and amino acids to a diet which was rich in fat--colostrum and milk. This was reflected by the intense up-regulation of plasma proteins related with lipid transport and lipoprotein metabolism during the first week of life.