Technical note: Evaluation of digital refractometers to estimate serum immunoglobulin G concentration and passive transfer in Jersey calves
| Autor: | M.M. McCracken, A.L. Fordyce, Howard D. Tyler, K.M. Morrill |
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| Rok vydání: | 2017 |
| Předmět: |
Immunity
Herd Immunodiffusion 040301 veterinary sciences Sensitivity and Specificity Immunoglobulin G 0403 veterinary science Animal science Refractometer Freezing Genetics Animals Total protein Radial immunodiffusion Brix Chromatography biology Chemistry Colostrum 0402 animal and dairy science Immunization Passive Technical note 04 agricultural and veterinary sciences 040201 dairy & animal science Refractometry Animals Newborn biology.protein Animal Science and Zoology Cattle Food Science |
| Zdroj: | Journal of dairy science. 100(10) |
| ISSN: | 1525-3198 |
| Popis: | Previous data have demonstrated that refractometers can be used to estimate serum IgG, and that a cut-point of 7.8% Brix should be used to identify failure of passive transfer (FPT) in 1-d-old Holstein calves. The objective of the present study was to validate the use of refractometry to estimate serum IgG concentrations and evaluate FPT in Jersey calves. Blood samples (n = 97) were obtained from 1- to 3-d-old Jersey calves and centrifuged at 3,300 × g for 20 min at 25°C. Serum was analyzed for % Brix, total protein (TP), and refractive index (nD) using a Sper Scientific Digital Refractometer (model #300036, Sper Scientific, Scottsdale, AZ) within 12 h of sampling. Samples were then frozen and later analyzed in the laboratory for IgG by radial immunodiffusion. The mean serum IgG concentration for all calves was 23.7 mg/mL (SD = 12.5), with a range of 2.3 to 65.5 mg/mL. Mean serum % Brix was 8.9 (SD = 1.1; range 6.5 to 12.0). Serum % Brix was moderately correlated with IgG concentration (r = 0.77). Total protein and IgG were moderately correlated (r = 0.790). Regression was used to determine cut-points for approximately 10, 12, and 14 mg of IgG/mL and to determine the sensitivity and specificity of refractometry to identify FPT (serum IgG |
| Databáze: | OpenAIRE |
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