Effect of udder inflammation on milk immunoglobulins and phagocytosis

Udder inflammation was induced in two quarters in each of eight cows by infusing oyster glycogen in saline solution. Milk was collected before and after infusion for immunoglobulin (Ig) and phagocytosis assays. Milk Ig and bovine serum albumin were measured by single radial immunodiffusion. The concentrations (mg/ml) of the immunoglobulins (IgA, IgG1, IgG2, and IgM) and bovine serum albumin before and after infusion were: IgA = 0.064 (before), 0.084 (after); IgG1 = 0.323, 0.486; IgG2 = 0.046, 0.094; IgM = 0.091, 0.124; and bovine serum albumin = 0.207, 0.451. The fact that IgA, IgG1, IgG2, and IgM were significantly correlated with bovine serum albumin within the cows before and after inflammation suggests a passive transfer of these Ig during inflammation. Phagocytosis was determined by incubating polymorphonuclear leukcotyes collected after infusion with 32P-tagged Staphylococcus aureus in autologous skim milk collected before and after infusion. The difference in percentage of phagocytosis before (42%) and after (36%) infusion was not significant. None of the Ig were significantly correlated with phagocytosis.