Three-hundred healthy female Holstein calves were used for assessing reference values and ageing influence on the protein profile throughout the first month of life. The total protein values were lower on calves younger than 8 hours of life, increasing progressively until the 4th day when were recorded the highest value, remaining like this until the 30 th day. The level of albumin increased from 24 hours of life and more intensively from the 13-15th to the 30 th day when were recorded the highest value. No differences were recorded on the alphaglobulin concentrations throughout the study. The levels of betaglobulin increased until the 7-9th day, reaching the highest value and continuing similar until the end of the experiment. Lowest gammaglobulin levels were recorded on calves under 8 hours of life, than it showed an increase until the 2nd day, when it reached the highest values, remaining at similar levels until the 11th day; after that showed a continuing decrease until the 30th day of life. The albumin:globulin ratio presented its highest value at the 8th hour followed by a significant decrease until the 2nd day of life. Then it remained at similar levels until the 15th day when they had shown an increase until the end of the study. Ageing showed a significant influence for all biochemical variables studied, but the alphaglobulin.
Serum protein; Calf; Newborn
