01813nas a2200265   4500000000100000000000100001008004100002260007000043653001000113653002000123653001400143653002300157100001600180700001300196700001400209700001500223700001200238700001200250700001300262245010400275300001200379490000800391520113400399022001401533       2012                            d  c02/2012bSchlütersche Verlagsgesellschaft mbH & Co. KGaHannover10aBHV-110aIBR-gE antibody10apool milk10amilk concentration1 aC Schroeder1 aS Horner1 aN Bürger1 aC Engemann1 aU Bange1 aE Knoop1 aJ Gabert00aImproving the sensitivity of the IBR-gE ELISA for testing IBR marker vaccinated cows from bulk milk  a290-2960 v1253 aThe low sensitivity of the IBR-gE ELISA compared to other diagnostic ELISA tests for IBR is a major disadvantage of IBR control programmes based on IBR marker vaccination. Therefore the IBR-gE ELISA is not generally recommended for testing pooled or bulk milk samples. The aim of this study was to determine the performance of a commercially available kit for concentrating and purifying antibodies in milk in order to improve the sensitivity of detecting IBR-gE antibody positive cows from pooled and bulk milk samples.  A single IBR-gE positive cow is likely to remain undetected in a pool of 49 negative milk samples without concentration. By contrast, the bulk milk concentration procedure improved sensitivity from 5.4% to 75.7% in a positive herd. Milk samples with a high or moderate positive signal are more likely to be detected after pool milk concentration compared to weak positive samples.  Whereas a follow up study involving a monthly testing of bulk milk samples from three marker vaccinated IBR-gE negative herds over a period of seven months yielded negative results each month, bulk milk from a herd containing  a0005-9366