Comparison of rapid laboratory tests for failure of passive transfer in the bovine

Abstract

BackgroundFailure of passive transfer of maternal immunity via colostrum can occur in the bovine, and a number of blood tests have been developed to test calves for this failure. It is not clear which test is most suitable for this purpose. The objective was to examine the most commonly used tests for failure of passive transfer and to decide which is most suitable for routine laboratory use. 126 serum samples were taken from calves of dairy cows after birth but prior to colostrum feeding, and at 48 h of age. Five different tests were compared against radial immunodiffusion which is considered the appropriate reference method. These tests were serum gamma-glutamyltransferase levels, serum protein levels, serum globulin levels, an enzyme linked immunosorbent assay and the zinc sulphate turbidity test.ResultsThe tests examined displayed high sensitivity but widely varying specificity. Examination of the use of different cut-off points allowed some improvement in specificity at the expense of sensitivity, but the tests which had performed best at the original cut-off points still displayed the best performance. Gamma-glutamyltransferase levels as a measure of colostrum absorption returned, in this study, the best balance between sensitivity and specificity. The ELISA used in this study and serum globulin levels displayed performance similar to the gamma-glutamyltransferase levels. Serum total protein was less successful than others examined at providing both sensitivity and specificity but may, when performed via refractometer, be useful for on-farm testing. As currently performed the poor sensitivity for which the zinc sulphate turbidity test is most often criticized is evident. Modification of the cut-off point to increase specificity is less successful at balancing these parameters than the ELISA, gamma-glutamyltransferase levels, and globulin levels.ConclusionsGamma-glutamyltransferase levels, ELISA testing and circulating globulin levels performed best in detecting failure of passive transfer in serum samples, although all three had some practical considerations.

Evaluation of 5 methods for diagnosing failure of passive transfer in 160 Holstein calves

“…In this study, the ZST test had the lowest AUC for diagnosing http://FTPI. The majority of studies that evaluated the diagnostic performance of the ZST test for detecting FPTI found variable Se and Sp values for diagnosing FPTI . Our results were in agreement with the findings of most studies; we identified an Se = 100% and an Sp = 67% at an optimal cut point for the ZST test of <14.6 g/L for diagnosing FPTI.…”

“…A diagnostic test with a high Se should be selected as a screening test. Concerns have been expressed about the effect of temperature on the ZST reaction, the effect of CO 2 on the ZnSO 4 solution, and the effect of the degree of hemolysis in the serum samples, although modifications have been proposed to reduce errors due to hemolysis …”

“…The diagnostic test performance at the optimal cut point was compared to the performance at standard or currently recommended cut points. Test characteristics were also compared using the following standard cut points for the 4 tests: Brix refractometry, 7.8%; STP concentration measured with digital refractometry or a photometric method, 52 g/L; serum GGT activity, 750 and 1000 U/L; and ZST test, 10 and 12 g/L (unpublished observations from Ghorbanpour and Zakian).…”

Serum proteins and their diagnostic utility in veterinary medicine: a review

“…The addition of salts causes turbidity, which may be visually evaluated or measured using a spectrophotometer as units of turbidity. This method may be used as a field test for the evaluation of suckling efficiency or failure of passive transfer of maternal immunity via colostrum in calves and foals (Sedlinska et al 2005;Hogan et al 2015). Currently, the bromcresol green (BCG) and bromcresol purple methods are the basis for the determination of serum albumin (Watanabe et al 2004).…”

Brix Refractometry of Colostrum from Primiparous Dairy Cows and New-Born Calf Blood Serum in the Evaluation of Failure of Passive Transfer

“…Protection from infectious diseases of newborn calves is completely dependent on the success of passive transfer of maternal IgG via the colostrum [2]. Because of that, failure of passive transfer (FPT) of colostral immunoglobulins, composed mainly of IgG [2], is associated with increased morbidity and mortality [2][3][4][5][6][7][8][9][10][11]. FPT of immunoglobulins is defi ned as a circulating IgG concentration less than 10 g/L in newborn calves between 24 and 48 hours of age [12,13].…”