Shedders panel. To compare relative sensitivity of fecal
culture and serologic tests, serum samples were collected
from 198 Mptb culture-positive cows originating from 53
dairy herds. None of these animals showed clinical symptoms
of paratuberculosis. Samples were taken from the coccygeal
vein using Clot Activator Vacutainerti serum tubes.
Tubes were identified with self-adhesive labels preprinted
that showed the bar code for each cow, as recorded in the
Dutch Identification and Registration system.15
Specificity panel. To compare specificity of the serologic
tests, blood samples were collected from approximately 20
randomly chosen cows per herd from 41 nonsuspect dairy
herds. Sampling technique was identical to collection of
samples of the shedders panel. Selected herds were managed
under a closed-herd system and were free of clinical signs
of paratuberculosis. Closed herd management for .3 yr and
absence of clinical signs for .5 yr were verified by the Animal
Health Service. Fecal pools of all adult cows (.2 yr)
were cultured for Mptb, and only negative results were obtained,
and blood samples were collected as soon as culture
results were available.