Evaluation of 3 Assays for Failure of Passive Transfer in Calves

Abstract

This study examined the sensitivity, specificity, predictive values, and classification accuracy of 3 commonly used screening tests for failure of passive transfer: the sodium sulfite turbidity test, the zinc sulfate turbidity test, and refractometry relative t o serum immunoglobulin G1 (IgG,) concentrations determined by radial immunodiffusion. Serum samples were obtained from 242 calves ranging from 1 t o 8 days of age. Using a serum concentration of 1,000 mg/dL IgG, t o define adequate passive transfer, the zinc sulfate test had a sensitivity of 1.00 and a specificity of 0.52 in the detection of inadequate passive transfer. The endpoint of the test appeared t o be higher than desired; calves testing negative had mean serum lgG, concentration of 955 mg/ dL and a large proportion of calves with adequate passive transfer were misclassified as positive for failure of passive transfer. Using the qualitative zinc sulfate test, the percentage of calves correctly classified with regard t o passive transfer status was less than that observed with either the sodium sulfite test or refractornetry. The sensitivity of the sodium sulfite assay was 0.85 at a 1 + endpoint and 1.00 at alves are born without appreciable serum concentra-C tions of immunoglobulin (Ig). Ig requirements are satisfied by ingesting and absorbing colostral 1gs.l.' Adequate passive transfer of Igs is a critical determinant of calf health and s~r v i v a l .~~' Several assays have been used to measure serum Ig concentrations in neonatal livestock. These include refractometer determination of total serum protein concentration, zinc sulfate and sodium sulfite turbidimetry, immunoassays, and the glutaraldehyde clot test.'.*-'' Assay procedures should be adapted to a practice setting. Immediacy of results permits practitioners to provide feedback to calfrearing personnel and make clinical decisions regarding the necessity of targeted intervention in individual calves with failure of passive transfer (FPT).Immunoassay procedures detecting bovine IgG have not been successfully adapted to a practice setting. Additionally, the time constraints of sample collection, sample submission, and assays procedures often relegate the results of immunoassays to historical interest. Labor and expense also have limited the widespread on-farm application of immunoassay procedures. The recently developed and marketed whole blood glutaraldehyde coagulation test attempted to address these timing and economic constraints; however, the sensitivity and specificity of the assay proved inadequate for routine diagnostic use." The primary goal of this study was to compare the sensitivity, specificity, and predictive values of 3 commonly used screening tests for the detection of FPT in calves. These test procedures included refractometry, the qualitative zinc sulfate turbidity test, and the semiquantitative sodium sulfite turbidity test. All 3 assays are readily adapted to a farm or practice setting. Assay results were compared with serum IgG I concentrations determined by radial immu...

Correlation of Serum IgG Concentration in Foals and Refractometry Index of the Dam’s Pre- and Post-Parturient Colostrums: An Assessment for Failure of Passive Transfer in Foals

“…However, the results of several reports have indicated that this test is an unreliable indicator of FPT in foals [12,34,41]. It is considered that the cause of these results is the wide range of STP concentrations in newborn foals before nursing colostrum [41], unlike in calves [45]. This finding is not surprising given that dehydration and variable serum albumin concentrations in hypogammaglobulinemic foals can produce STP concentrations within the reference range for normal foals [25].…”

“…This means this test may be routinely used on a breeding farm or in a field situation, because rapid results are required for determin-ing the necessity of therapeutic intervention in FPT cases in foals. However, several reports have indicated that this test is an unreliable indicator of FPT in foals [12,34,41] because unlike in calves, there is a wide range of STP concentrations in newborn foals [41,45].…”

Late gestation supplementation of beef cows differing in body condition score: Effects on cow and calf performance1,2

“…Therefore, the improved energy status of the HBCS compared with the LBCS cows prior to study initiation may have ameliorated the potential negative effects on calf birth weight resulting from the lower energy status of the LBCS cows. There was no effect of treatment on calf serum IgG level at birth (P ≥ 0.30), and all IgG levels were sufficient to indicate successful transfer of passive immunity to the calf (Tyler et al, 1996).…”

Estado inmunológico de terneras y terneros de lechería en la región Huetar Norte de Costa Rica. Año II.

“…Tyler et al (1996) compararon el desempeño de pruebas comúnmente utilizadas para determinar la TIP, demostrando que una concentración de PST cercana a los 5,5 g/dl es equivalente a una concentración de 10 g de Igs por litro.…”