TY  - JOUR
A1  - Ghaffari, Morteza Hosseini
A1  - Bernhoeft, Katrin
A1  - Etheve, Stephane
A1  - Immig, Irmgard
A1  - Hoelker, Michael
A1  - Sauerwein, Helga
A1  - Schweigert, Florian J.
T1  - Technical note: Rapid field test for the quantification of vitamin E, beta-carotene, and vitamin A in whole blood and plasma of dairy cattle
T2  - Journal of dairy science
N2  - Fast and easy tests for quantifying fat-soluble vitamins such as vitamin E and vitamin A, as well as beta-carotene, in whole blood without a need to preprocess blood samples could facilitate assessment of the vitamin status of dairy cattle. The objective of this study was to validate a field-portable fluorometer/spectrophotometer assay for the rapid quantification of these vitamins in whole blood and plasma of dairy cows and calves. We measured the concentrations of vitamin E and beta-carotene in whole blood and plasma from 28 dairy cows and 11 calves using the iCheck test (Bio-Analyt GmbH, Teltow, Germany) and compared the results with the current analytical standard (HPLC) in 2 independent laboratories, one at the University of Potsdam (Germany) and at one at DSM Nutritional Products Ltd. (Kaiseraugst, Switzerland). For vitamin A, the HPLC measurements were done only in the laboratory in Germany. The whole-blood concentrations of vitamin E as determined by iCheck (blood-hematocritcorrected) ranged from 1.82 to 4.99 mg/L in dairy cows and 0.34 to 3.40 mg/L in calves. These findings were moderately correlated (R-2 = 0.66) with the values assessed by HPLC in dairy cattle (cows + calves). When calves were excluded, the correlation was higher (R-2 = 0.961). The beta-carotene and vitamin A values obtained by the reference method HPLC were highly correlated with the iCheck methods in whole blood (R-2 = 0.99 and 0.88, respectively). In plasma, we observed strong correlations between the concentrations assessed by iCheck and those of HPLC for vitamin E (R-2 = 0.97), beta-carotene (R-2 = 0.98), and vitamin A (R-2 = 0.92) in dairy cattle (cows + calves). For vitamin E, beta-carotene, and vitamin A, we compared the relationship between the differences obtained by the iCheck assay and the HPLC measurements, as well as the magnitude of measurements, using Bland-Altman plots to test for systematic bias. For all 3 vitamins, the differences values were not outside the 95% acceptability limits; we found no systematic error between the 2 methods for all 3 analytes.
KW  - vitamin
KW  - cow-side assay
KW  - HPLC
KW  - method comparison
Y1  - 2019
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/47762
SN  - 0022-0302
SN  - 1525-3198
VL  - 102
IS  - 12
SP  - 11744
EP  - 11750
PB  - Elsevier
CY  - New York
ER  -