title: Physiological and pathological factors influencing bovine immunoglobulin G2 concentration in milk.
abstract: Bovine IgG2 concentration was determined by radial immunodiffusion in 355 milk samples of uninfected quarters, 101 milk samples of infected quarters, and 118 blood serum samples from 42 Holstein-Friesian cows taken at 30, 150, and 270 d. Concentration of IgG2 in blood serum (11.3 mg/ml) was highest at the beginning of lactation (30 d). Immunoglobulin G2 concentration in milk (16.81 micrograms/ml) from cows with uninfected quarters was not affected by quarter location but was correlated with IgG2 concentration in blood serum (.30; P less than .001). The IgG2 concentration in milk was lower in midlactation (150 d: 14.81 micrograms/ml) and in the two first lactations. Immunoglobulin G2 concentration in milk was correlated with SCC. Quarter infection by Corynebacterium bovis or major pathogens increased IgG2 concentration up to 47.9 micrograms/ml for Staphylococcus aureus. Only S. aureus influenced IgG2 concentration in blood serum. Correlation between IgG2 content and SCC in milk decreased when quarters were infected, regardless of bacterial species.
authors.affiliation: Université Pierre et Marie Curie, Paris, France.
authors.forename: J P
authors.initials: JP
authors.lastname: Caffin
authors.forename: B
authors.initials: B
authors.lastname: Poutrel
mesh_terms: D000818:Animals; D002417:Cattle / Q000276:immunology*; D005260:Female; D007074:Immunoglobulin G / Q000032:analysis*; D007774:Lactation / Q000276:immunology*; D008414:Mastitis, Bovine / Q000276:immunology* / Q000382:microbiology; D008892:Milk / Q000166:cytology / Q000276:immunology*; D011247:Pregnancy
chemical_list: D007074:Immunoglobulin G