Enzyme‐Linked Immunosorbent Assay, Single Radial Immunodiffusion, and Indirect Methods for the Detection of Failure of Transfer of Passive Immunity in Dairy Calves

Abstract

Background: Confirmatory tests for failure of transfer of passive immunity (FTPI) in dairy calves require direct measurements of the serum immunoglobulin G concentration. Enzyme-linked immunosorbent assay (ELISA) has advantages over single radial immunodiffusion (SRID) in terms of cost and time.Objectives: To evaluate the agreement between ELISA and SRID, and to compare the diagnostic performance of ELISA with indirect methods, in the detection of FTPI in calves.Animals: One hundred and fifteen dairy calves (aged 0-10 days) from 23 calf-rearing facilities.Methods: Prospective, observational study. The agreement between SRID and ELISA was determined by the Bland-Altman method. Fixed bias (SRID À ELISA) was calculated. For comparison of the diagnostic performance of ELISA with indirect methods, sensitivity, specificity, and area under the curve (AUC) of receiver operating characteristic (ROC) curves were calculated at cut-off values of 500 and 1,000 mg/dL.Results: The agreement between SRID and ELISA was 94%. Fixed bias (SRID À ELISA) was 140 AE 364 mg/dL. The AUC and sensitivity of ELISA at the cut-off value of 1,000 mg/dL were higher than those of indirect methods (Po.004). The specificity of ELISA at the cut-off value of 1,000 mg/dL was not higher than that of indirect methods, except for serum total protein concentration assay.Conclusion and Clinical Importance: ELISA exhibited good diagnostic performance and good agreement with SRID. ELI-SA is an adequate method for both screening and confirmatory tests for FTPI in dairy calves at the cut-off value of 500 mg/dL.

Comparison of single radial immunodiffusion and ELISA for the quantification of immunoglobulin G in bovine colostrum, milk and calf sera

“…It is unknown as to why the reference serum IgG values are similar in both kits, yet the colostrum and sera samples when tested for IgG are very different. Lee et al (2008) reported ZST to be a useful screening device, showing high specificity but recommended confirmatory diagnosis of IgG concentration with a direct measure such as sRID; this is in agreement with the findings from this study. The Brix refractometer is a useful tool to indirectly assess the IgG concentration in colostrum; it is simple to use, rapid and inexpensive.…”

“…Contrastingly, Lee et al (2008) demonstrated a modified ELISA (Bethyl Laboratories, Montgomery, TX, USA); and the protocol described by Vetter et al (2013) to exhibit a good agreement (94%) with a commercially available sRID assay (Triple J Farms, Bellingham, WA, USA). This may be a consequence of the specific test kits used, as there may be differences between IgG concentrations of standards supplied with kits depending on how they are quantified.…”

“…Various laboratory techniques are currently available to measure the passive transfer of immunity from dam to calf, including refractometry (Bielmann et al 2010;Quigley et al 2013), sodium sulphite test (Pfeiffer and McGuire 1977), zinc sulphate turbidity (ZST) assay (McEwan et al 1970), whole blood glutaraldehyde coagulation (Tyler et al 1996), γ-glutamyl transferase (Braun et al 1982), single radial immunodiffusion (sRID) (Fleenor and Stott 1981;Ameri and Wilkerson 2008;Fecteau et al 2013) and enzyme-linked immunosorbent assay (ELISA) (Kummer et al 1992;Hurley et al 2004;Lee et al 2008). Weaver et al (2000) reported sRID and ELISA to be the only true and direct measures of serum IgG; the remainder of tests mentioned merely estimate the IgG concentration based on the level of total globulins or other proteins whose passive transfer are associated with IgG.…”

Quantification of bovine immunoglobulin G using transmission and attenuated total reflectance infrared spectroscopy

“…This suggests that the likelihood of consequential misdiagnosis is small; the false-negative samples correspond to only partial FTPI, with minimal risk of calf morbidity and mortality. 15,24 The positive and negative predictive values (PPV and NPV, respectively) vary with both test performance and the population FTPI prevalence. 32 In North America, the reported prevalence of FTPI in dairy calves ranges from 19% to 40%.…”

Brix Refractometry of Colostrum from Primiparous Dairy Cows and New-Born Calf Blood Serum in the Evaluation of Failure of Passive Transfer

“…The RID assay is an expensive laboratory procedure, demands special equipment and educated technicians. Besides, it is time consuming (requires 18 to 72 h to determine the results), and as such, it is not suitable for on-farm use [16,17].…”