A Quantitative Serologic Assay for Diagnosing Congenital Infections of Cattle

Abstract

SUMMARY Serums prepared from samples of blood collected from 126 bovine fetuses, 100 newborn calves before they were given colostrum, and 23 postcolostral calves were quantitatively measured by the single radial immunodiffusion technique for immunoglobulins G and M (IgG and IgM). These values were compared with the serum values for fetuses and precolostral calves with experimentally induced and naturally occurring congenital infections, including those produced by chlamydia, Vibrio fetus, Coxiella burnetii, Anaplasma marginale , bluetongue virus, bovine viral diarrhea ( bvd ) virus, and agent of epizootic bovine abortion ( eba ). The geometric mean for serum IgM concentrations in control fetuses and precolostral control calves reached 0.11 mg./ml. for newborn precolostral calves, whereas the IgG values in the same animals reached 0.16 mg./ml. The geometric means for samples from postcolostral control calves were 1.75 and 7.55 mg./ml. for IgM and IgG, respectively. Samples from fetuses and precolostral newborn calves that were infected had increased IgM (0.18 to 0.62 mg./ml.) and IgG (1.21 to 3.47 mg./ml.) values relative to the control fetal and precolostral newborn groups. Furthermore, specific antibodies appeared in calves infected with C. burnetii , bvd virus, V. fetus , bluetongue virus, and chlamydia. Collection of serum samples from precolostral calves possibly having a congenital infection, utilization of the single radial immunodiffusion test, and specific serologic tests may provide a means of diagnosing intrauterine infections.