Comparison of turbidometric immunoassay and brix refractometry to radial immunodiffusion for assessment of colostral immunoglobulin concentration in beef cattle.
J Vet Intern Med
; 37(5): 1934-1943, 2023.
Article
in En
| MEDLINE
| ID: mdl-37596893
ABSTRACT
BACKGROUND:
Colostral immunoglobulin G (IgG) concentration is critical to the attainment of adequate transfer of passive immunity in cattle, however, studies comparing available tools for measurement of colostral IgG concentration in beef cattle are limited.OBJECTIVES:
To report the agreement between 3 commercially available tests for evaluating IgG concentration in beef colostrum. ANIMALS Two hundred six beef-breed cows hospitalized for calving management or dystocia.METHODS:
Retrospective study to assess IgG of whole colostrum measured stall-side via turbidimetric immunoassay (TI) and brix refractometry (BRIX), compared to fat separated (FS) analysis via single radial-immunodiffusion (RID; reference standard), TI-FS and BRIX-FS. Test performance was assessed using Passing Bablock regression, Bland-Altman analysis, and area under the curve to determine optimal thresholds.RESULTS:
Correlation between RID and TI-FS, BRIX-FS, or BRIX was similar (Spearman's ρ = 0.717, 0.715, 0.716, respectively) but correlation for TI was poor (ρ = 0.586). Regression analysis identified a substantial constant (-214.75 [CI -272.03 to -178.07]) and proportional (13.24 [CI 11.81-15.37]) bias between the RID and TI-FS which was similar for TI. TI-FS concentrations of 28.47, 38.75, and 50.62 g/L, BRIX-FS of ≤21.9%, ≤24.0%, and ≤27.4%, and BRIX of ≤21.3%, ≤23.8%, and ≤26.4% indicated IgG concentrations <50, <100, and <150 g/L, respectively; appropriate cutoffs for TI could not be generated. CONCLUSIONS AND CLINICAL IMPORTANCE Both TI and TI-FS demonstrated a large constant and proportional bias compared to RID; BRIX and BRIX-FS were well correlated with RID and remain a reliable method for estimation of colostral IgG concentration in beef cattle.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Refractometry
/
Colostrum
Type of study:
Observational_studies
/
Prognostic_studies
Limits:
Animals
/
Pregnancy
Language:
En
Journal:
J Vet Intern Med
Journal subject:
MEDICINA INTERNA
/
MEDICINA VETERINARIA
Year:
2023
Document type:
Article
Affiliation country:
United States
Publication country:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA