Using serum and plasma samples to assess failure of transfer of passive immunity in dairy calves

Abstract

The objectives of this study were (1) to determine the differences in IgG and total protein (TP) content of serum and plasma samples collected from the same calves; (2) to evaluate the correlation between calf serum and plasma IgG levels, Brix scores, and TP concentrations; (3) to determine whether different cutoff values should be used for plasma and serum to assess failure of transfer of passive immunity (FTPI) in dairy calves; and (4) to evaluate the level of agreement between results obtained from using serum and plasma samples of the same calves to assess FTPI using optimal cutoff values. Blood samples (n = 217) were collected from Holstein calves at 3 to 10 d of age on 30 commercial dairy farms in Nova Scotia and Newfoundland, Canada. Paired serum and plasma samples were analyzed for IgG concentration by the reference radial immunodiffusion assay, transmission infrared (TIR) spectroscopy, digital and optical Brix refractometers, and optical TP refractometer. The IgG concentrations measured by RID and TIR spectroscopy in serum were similar to those in plasma. However, the Brix and TP refractometer readings were significantly higher in plasma than in serum. The prevalence of FTPI in serum and plasma samples based on a RID-IgG concentration <10 g/L was 43.3 and 46.5%, respectively. The RID-IgG concentration was correlated with TIR-IgG (r = 0.92 and 0.89), digital Brix (r = 0.80 and 0.80), optical Brix (r = 0.77 and 0.77), and optical TP (r = 0.75 and 0.77) refractometers in serum and plasma, respectively. The correlations between paired serum and plasma IgG content were 0.85 by TIR spectroscopy, 0.80 by digital Brix, 0.77 by optical Brix, and 0.79 by optical TP refractometer. The optimal cutoff values for TIR spectroscopy, digital Brix, optical Brix, and TP refractometers to assess FTPI using serum were 13.1 g/L, 8.7% Brix, 8.4% Brix and 5.1 g/dL, respectively; and the optimal cutoff values with plasma were 13.4 g/L, 9.4% Brix, 9.3% Brix and 5.8 g/dL, respectively. When using these optimal cutoff values, the level of agreement (88.1%) between results derived from testing serum and plasma by TIR spectroscopy was substantial, with a kappa (κ) value of 0.76. The results derived from testing serum and plasma by digital Brix refractometer showed substantial agreement (83.4%), with a κ value of 0.65, which is higher than the agreement and κ value (74.7% and 0.51) reported for the optical Brix refractometer. Substantial agreement (81.6%) between serum and plasma TP was also obtained when using the optical TP refractometer, with a κ value of 0.63. In conclusion, serum or plasma samples can be used interchangeably for measuring IgG concentrations and assessing FTPI in dairy calves. However, different cutoffs must be used to assess FTPI depending on the sample matrix. Furthermore, results obtained from serum samples showed higher agreement with the reference RID assay than those obtained from plasma samples.

Evaluation of 3 refractometers to determine transfer of passive immunity in neonatal beef calves

“…Even in dairy calves, no agreement on the most appropriate STP thresholds has been reached, with recently suggested optimal thresholds ranging from 5.1 to 5.8 g/L. 9,[26][27][28][29][30] We acknowledge the limited usefulness of our proposed thresholds for detection of IgG <10 g/L in populations similar to ours. As shown in 31,32 , and also reflects the generally high average colostral IgG concentration in western Canadian beef cows.…”

Colostrum Management for Dairy Calves

“…Other analytes, such as serum total protein (STP), have been extensively validated, are easily measured at the farm level, and are more economical than measuring IgG directly. 125,126 STP levels in healthy calves should be evaluated from blood samples collected from 24 hours after the first colostrum feeding to 10 days of age. 127 The earlier in this sampling window that samples are collected, the more accurately the results reflect true IgG absorption and the less likely it is for results to be influenced by IgG distribution/decay or dehydration.…”

Orientações a Proprietários De Equídeos De Trabalho E Lazer Em Bandeirantes E Região, Visando a Prevenção De Doenças, Acidentes No Trânsito, E Melhoria Do Bem-Estar Humano E Animal

“…Outra forma de mensurar a ingestão de colostro pelo animal é através da dosagem de proteínas plasmáticas totais (PPT). Os níveis de PPT no plasma do neonato se elevam devido à presença no sangue das IgGs do colostro 24h após sua ingestão, sendo que valores abaixo de 5,6g/dL (MACFARLANE et al, 2014) a 5,8g/dL já caracterizam falha na transferência de imunidade passiva (ELSOHABY et al, 2018). Sendo assim, as PPT não são apenas um indicativo da ingestão do colostro, mas também da sua qualidade, por mensurar a quantidade de IgG transferida (ROCHA et al, 2012).…”