Related Experiment Video
Updated: May 21, 2025
Intranasal Immunization and Milk Collection in Studies of Maternal Immunization in New Zealand White Rabbits Oryctolagus cuniculus
Published on: July 31, 2021
The diagnostic accuracy of the Brix refractometer in determining mare colostrum with high and low immunoglobulin G
1Department of Livestock, Dalaman Agricultural Enterprise, General Directorate of Agricultural Enterprises, 48770 Dalaman, Muğla, Türkiye.
Background:
Foals, that receive poor-quality colostrum, are exposed to a risk of failure of transfer of passive immunity. The Brix refractometer can be used for the estimation of the immunoglobulin (IgG) concentration of mare colostrum, yet there is a scarce literature available on Brix refractometer thresholds for use in the detection of mare colostra with high and low IgG concentrations.
Aim:
This study aimed to assess the diagnostic accuracy of the Brix refractometer in determining mare colostra with IgG concentrations of <50g/L, <60g/L, ≥80g/L, ≥100g/L and ≥125g/L.
Materials And Methods:
Two hundred and seventeen Arabian mares had colostral IgG concentrations measured with the radial immunodiffusion assay and estimated with the Brix refractometer. Brix thresholds were determined by performing a receiver operating characteristics analysis.
Results:
The mean colostral IgG concentration was 83.73 ± 2.46 g/L and colostral IgG concentrations had a high correlation (Pearson's r=0.78) with Brix percentages. The optimal refractometer thresholds for the determination of colostral IgG concentrations of <50, <60, ≥80, ≥100 and ≥125 g/L were ascertained to be ≤19.6 %, ≤20.1 %, >21.6 %, >23.6 % and >27.3 %, respectively. The sensitivity and specificity of the Brix refractometer for the determination of colostral IgG concentrations of <50, <60, ≥80, ≥100 and ≥125 g/L were found to be 89.3 % (95 % CI: 71.8-97.7 %) and 83.8 % (95 % CI: 77.5-89.0 %); 82.0 % (95 % CI: 68.6-91.4 %) and 88.1 % (95 % CI: 81.8-92.8 %); 85.3 % (95 % CI: 76.9-91.5 %) and 73.7 % (95 % CI: 63.9-82.1 %); 84.8 % (95 % CI: 73.0-92.8 %) and 76.1 % (95 % CI: 68.2-82.8 %); and 75.0 % (95 % CI: 53.3-90.2 %) and 90.4 % (95 % CI: 85.1-94.3 %), respectively.
Conclusion:
The digital Brix refractometer showed a good performance in determining mare colostra with low and high IgG concentrations.
