Original Research ARTICLE
Comparison of alternative meat inspection regimes for pigs from non-controlled housing – considering the cost of error
- 1Food Safety & Veterinary Issues, Danish Agriculture and Food Council, Denmark
- 2Department of Economics, School of Arts and Social Sciences, City of London College, United Kingdom
- 3Department of Hygiene and Preventive Medicine, Kafrelsheikh University, Egypt
- 4Veterinary Epidemiology, Economics and Public Health Group, Royal Veterinary College, United Kingdom
- 5Department of Epidemiological Sciences, Animal and Plant Health Agency (United Kingdom), United Kingdom
Denmark has not had cases of bovine tuberculosis (bovTB) for more than 30 years but is obliged by trade agreements to undertake traditional meat inspection (TMI) of finisher pigs from non-controlled housing to detect bovTB. TMI is associated with higher probability of detecting bovTB but is also more costly than visual-only inspection (VOI). To identify whether VOI should replace TMI of finisher pigs from non-controlled housing, the cost of error – defined here as probability of overlooking infection and associated economic costs - should be assessed and compared with surveillance costs.
First, a scenario tree model was set up to assess the ability of detecting bovTB in an infected herd (HSe) calculated for three within-herd prevalences, WHP (1%, 5% and 10%), for four different surveillance scenarios (TMI and VOI with or without serological test, respectively). HSe was calculated for six consecutive 4-week surveillance periods until predicted bovTB detection (considered high-risk periods HRP). 1-HSe was probability of missing all positives by each HRP. Next, probability of spread of infection, Pspread, and number of infected animals moved were calculated for each HRP. Costs caused by overlooking bovTB were calculated taking into account Pspread, 1-HSe, eradication costs, and trade impact. Finally, the average annual costs were calculated by adding surveillance costs and assuming one incursion of bovTB in either 1, 10 or 30 years. Input parameters were based on slaughterhouse statistics, literature and expert opinion.
Herd sensitivity increased by high-risk period and within-herd prevalence. Assuming WHP=5%, HSe reached median 90% by 2nd HRP for TMI, whereas for VOI this would happen after 6th HRP. Serology had limited impact on HSe. The higher the probability of infection, the higher the probability of detection and spread. TMI resulted in lowest average annual costs, if one incursion of bovTB was expected every year. However, when assuming one introduction in 10 or 30 years, VOI resulted in lowest average costs. It may be more cost-effective to focus on imported high-risk animals coming into contact with Danish livestock, instead of using TMI as surveillance on all pigs from non-controlled housing.
Keywords: surveillance, Outdoor production, early warning, Mycobacterium bovis, Meat inspection, cost of error, pigs
Received: 21 Dec 2017;
Accepted: 13 Apr 2018.
Edited by:Marta Hernandez-Jover, Charles Sturt University, Australia
Reviewed by:GUSTAVO MACHADO, University of Minnesota, United States
Céline Faverjon, Universität Bern, Switzerland
Copyright: © 2018 Hansen, Nielsen, El Tholth, Haesler, Foddai, and Alban. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Lis Alban, Danish Agriculture and Food Council, Food Safety & Veterinary Issues, Copenhagen, Denmark, email@example.com