Authors : Jae-Hoon Kim, Tamanna Jahan Mony, Fazle Elahi, Suman Paul, Mohammadmejbah Uddin, Jong-Soo Lee and Md. Bashir Uddin
Abstract: Avian Salmonellosis is considered as one of the major diseases in layer industry. In resource-limited condition diagnosis of Salmonellosis is based on subjective postmortem examination. Discriminatory power of this subjective diagnosis has not been systematically examined before. Thus, the present study examined the discriminatory power of the postmortem lesions for diagnosing Salmonellosis in the layer flocks. Multivariable diagnostic model based on postmortem lesions was developed to diagnose Salmonellosis in layer chicken. Post-mortem examinations of 430 dead chickens have been performed of which 138 (32.09%) were found Salmonellosis positive based on the postmortem lesions. The 17.4% (24 out of 138) of postmortem suspects were confirmed Salmonella positive by laboratory tests. In univariable analysis enlarged liver, bronze liver, enlarged spleen, oophoritis, haemorrhage in the intestine and necrotic foci in the liver all produced a p = 0.1 and were included in the multivariable model. The multivariable diagnostic model was developed using logistic regression and backward elimination procedure. Enlarged liver, bronze liver, enlarged spleen, oophoritis, the haemorrhage in the intestine were found significant (p = 0.05) in the final model. Hosmer and Lemeshow goodness of fit statistics for the final diagnostic model had a p-value estimate of 0.544 which indicates a good model fit. The area under the ROC curve was 0.826 which shows moderately high diagnostic discriminatory power. As the postmortem lesions demonstrated a moderately high discriminatory power to differentiate Salmonella positive birds from negative birds, postmortem lesions based diagnosis of Salmonellosis could be considered as a useful approach in resource-limited countries where access to the diagnostic laboratory is limited.
Jae-Hoon Kim, Tamanna Jahan Mony, Fazle Elahi, Suman Paul, Mohammadmejbah Uddin, Jong-Soo Lee and Md. Bashir Uddin, 2017. An Assessment of Discriminatory Power of Postmortem Lesions for Diagnosis of Salmonellosis in Field Condition in Laying Flocks. Journal of Animal and Veterinary Advances, 16: 69-74.