Management practices associated with Mycobacterium avium subspecies paratuberculosis infection and the effects of the infection on dairy herds

2008 ◽  
Vol 162 (19) ◽  
pp. 614-617 ◽  
Author(s):  
F. J. Dieguez ◽  
I. Arnaiz ◽  
M. L. Sanjuan ◽  
M. J. Vilar ◽  
E. Yus
2012 ◽  
Vol 95 (4) ◽  
pp. 1855-1872 ◽  
Author(s):  
J. Cho ◽  
L.W. Tauer ◽  
Y.H. Schukken ◽  
M.I. Gómez ◽  
R.L. Smith ◽  
...  

2015 ◽  
Vol 144 (2) ◽  
pp. 413-424 ◽  
Author(s):  
K. DONAT ◽  
N. HAHN ◽  
T. EISENBERG ◽  
K. SCHLEZ ◽  
H. KÖHLER ◽  
...  

SUMMARYThe control of Johne's disease requires the identification of Mycobacterium avium ssp. paratuberculosis (MAP)-positive herds. Boot swabs and liquid manure samples have been suggested as an easy-to-use alternative to sampling individual animals in order to diagnose subclinical Johne's disease at the herd level, but there is a need to evaluate performance of this approach in the field. Using a logistic regression model, this study aimed to calculate the threshold level of the apparent within-herd prevalence as determined by individual faecal culture, thus allowing the detection of whether a herd is MAP positive. A total of 77 boot swabs and 75 liquid manure samples were taken from 19 certified negative and 58 positive dairy herds. Faecal culture, three different polymerase chain reaction (PCR) methods and the combination of faecal culture with PCR were applied in order to detect MAP. For 50% probability of detection, a within-herd prevalence threshold of 1·5% was calculated for testing both matrices simultaneously by faecal culture and PCR, with the threshold increased to 4·0% for 90% probability of detection. The results encourage the use of boot swabs or liquid manure samples, or a combination both, for identifying MAP-positive herds and, to a certain extent, for monitoring certified Johne's disease-negative cattle herds.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8081 ◽  
Author(s):  
Tapakorn Chamchoy ◽  
Deneice R. Williams ◽  
John M. Adaska ◽  
Randall J. Anderson ◽  
Sharif S. Aly

Mycobacterium avium subspecies paratuberculosis (MAP) is a bacterium that can cause substantial economic losses in infected dairy herds due to reduced milk production and increased cow-replacement costs. In order to control MAP in dairies with drylot pens, a standardized environmental sampling protocol to quantify MAP in fecal slurry was developed based on an existing protocol for freestall pens. Specifically, following a 24 h hold of the flush, a grab sample of approximately 10 ml of fecal slurry was collected every 1 m along the flush lane of the drylot pens, avoiding individual cow fecal pats. To determine the reliability and repatability of the new environmental sampling protocol for estimation of MAP bioburden at the pen level, two collectors simultaneously collected fecal slurry samples every day for 3 days from six drylot cow pens on two Central California dairies. During the study period no cow movement between pens was allowed with the exception of sick cows. The study herds had MAP seroprevalence of 5.8% and 3.2%, respectively, based on whole pen serum ELISA results. Variance components models for quantitative real-time PCR (qPCR) results showed samples collected from different pens on different dairies accounted for greater variablitiy in MAP concentration (65%), while samples collected by different collectors had the least variability (0.1%). In contrast, variability in MAP concentration in environmental samples collected on different days had 25% variability. The intraclass correlation coefficient showed high reliability (93%) of environmental sampling simultaneously by different collectors. In contrast, the reliability of environmental sampling at different days was 65%, which was similar to the reliability for sampling by different collectors on different days. Investigators can expect high reliability when employing the new environmental sampling protocol along with qPCR testing of environmental samples from drylot pens.


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