Serum Protein of Female Holstein Calves Fed Milk through Step-Down and Conventional Methods

The serum proteinograms of 10 female Holstein calves fed milk either through conventional (COV) or step-down (STP) milk feeding methods at different ages were evaluated. Calves fed using the COV method were fed colostrum during the first 24 hours that they stayed with their respective mothers and received transition milk for another 2 days and later, and then milk at four liters/day for 59 days. Calves fed using the STP method were fed colostrum and then milk as follows: Six liters of milk/day from days six to 25 after birth, four liters of milk/day from days 26 to 45, and two liters of milk/day from days 46 to 59 after birth. Blood sampling was performed at 7, 21, 28, 42, 49 and 56 days of age. For calves fed using either of the two milk feeding methods, the serum concentration of albumin increased, while the serum concentration of β-globulin decreased with increasing calf age. Calves fed using the COV method had higher serum total protein, globulin, β-globulin, and γglobulin concentrations, while the concentrations of A/G, α1-globulin, and α2-globulin were higher for calves in the STP group. These results are important for establishing the serum protein profile of calves, which is significantly influenced by milk feeding methods and calf age.