Project MC1003 Assessment of the benefit to public and animal health, and animal welfare of post ...

218 Pages·2011·5.12 MB·English

RESEARCH PROJECT -
FINAL REPORT FORM

Section 1 : Project Details

1.1 Agency Project Code(s) MC1003 / FS245010

Outcomes and values of current ante and post-
mortem inspection tasks & assessment of the
Project Title
1.2 benefits to public and animal health of post-mortem
(from Contract)
inspection of green offal in red meat species at
slaughter.

1.3 Project start date 01 May 2010

1.4 Project end date 31 January 2011

1.5 Date final report submitted 11 February 2011

1.6
Agency Project Officer Carles Orri

1.7 Name and address of
Royal Veterinary College
Lead Contractor
Hawkshead Lane
North Mymms
Hatfield AL9 7TA
Herts, UK
1.8 Lead Contractor Project Leader

Nam e Silvia Alonso

Tele phone [phone]

FAX [phone]

E-ma il [email protected]
E
1.9 Colla-borating Partners or Danish Agriculture and Food Council (DAFC),
sub-cmontractors Denmark
a
i Food Institute for Risk Analysis, Germany
l
Section 2: Key Findings - Executive Summary

The aim of this research project is to address the following policy questions:
a) what is the value of current ante and post-mortem inspection tasks; and
b) what are the contributions to public health, animal health and welfare of post-mortem inspection of
green offal in red meat species at slaughter.
These two questions were merged into one project as most of the preparatory work was common to
both pieces of research. However, findings are reported separately so as to provide a cohesive
response to each individual question.
Background
The current meat inspection (MI) system for cattle, sheep and pigs in Europe was established at the
end of the 19th century with the aim to protect consumers from diseases such as tuberculosis,
brucellosis and human teaniasis acquired from animals.
This MI system consists of checking animals and their organs for lesions and abnormalities, which is
done visually, through palpation or incision as required. Post-mortem inspection relies solely on the
detection of macroscopic lesions (visible to the naked eye) caused by pathogens or other hazards in
the carcase and organs of affected animals. After targeted effort, including surveillance and
eradication programmes, many of these diseases have either been eradicated in Europe, or their
prevalence has been greatly reduced, decreasing their significance to public and animal health.
MI requirements are set out in directly applicable EC regulations. The current MI system allows for
limited flexibility and does not follow risk assessment principles. This is a costly system that requires
a great deal of public resources dedicated to carcase inspection.

Rationale and Objectives
Today, the most important meatborne hazards causing human disease are Campylobacter,
Salmonella, Yersinia and E. coli. These do not typically cause clinical disease nor are they visible to
the naked eye, and are therefore unlikely to be effectively detected by traditional MI tasks. They are
usually transmitted to the carcase through faecal or other contamination routes during the slaughter
process. In this context, the MI system as a whole, or some MI tasks in particular, may no longer be
fit for purpose. Thus, MI should be reviewed and more effective ways of addressing the new threats
to human health should be considered. In addition to that, consideration should be given to the
potential contribution of MI tasks to cross-contamination of carcases.
Notwithstanding this, many important hazards and conditions associated with animal health (including
endemic and exotic infectious diseases) and animal welfare can be detected at the slaughterhouse.
This adds complexity to the study of the contribution of each MI task to protecting animals and
humans.
Elimination of MI tasks that do not contribute meaningfully to the detection of hazards could
potentially free resources that could be used elsewhere to control meatborne diseases. However, this
might result in an increased risk to humans and animals from pathogens currently being controlled. In
order to evaluate the contribution of MI to public health, animal health and welfare, an assessment of
the effectiveness of all MI tasks in relation to the most important hazards must be carried out.

Approach
Work has been carried out in three stages:
1) Identification of relevant hazards
The most important public health (PH), animal health (AH) and animal welfare (AW) hazards
associated with red meat production (cattle, sheep and pigs) were identified using available scientific
literature and published reports. Legally required MI tasks (both ante-mortem, AM and post-mortem,
PM) for these three species were mapped and their potential to detect the identified hazards was
evaluated.
2) Development of a tool to evaluate the effectiveness of the MI system
This step addresses the first policy question. A tool was developed for the qualitative assessment of
the detection capacity of each MI task. The assessment of effectiveness is mainly based on two
parameters: the Sensitivity (Se) and the Positive Predictive Value (PPV). Sensitivity is defined as the
proportion of positive (i.e. infected) carcases that are identified as positive by the MI task. PPV is the
proportion of carcases identified as positive that are actually positive. The combination of these two
parameters provides a general estimate of the capacity of a task to effectively detect a hazard. For
this model, literature, available databases and expert opinion were used to obtain Se and PPV
estimates for each task. These were then transformed into qualitative estimates (very low, low,
medium, high and very high), and combined to produce an overall qualitative score which defined the
task‟s “capacity of detection” of a hazard. The qualitative assessment tool was applied to a selection
of hazards with the purpose of validating the model. The hazards included were:
Public health - Salmonella in pigs and Toxoplasmosis in sheep;
Animal health - M. bovis (bTB), M. avium subsp paratuberculosis (MAP) in cattle and
Classical Swine Fever in pigs;
Animal welfare - Tail Biting and Hernia in pigs.
3) Risk assessment of green offal inspection
This step relates to the second policy question. An assessment of the risk to animals and humans
from changes in MI practices, specifically in green offal inspection, was carried out for the
abovementioned selection of hazards, using the Codex Alimentarius risk assessment framework. A
risk pathway mapping all the steps of red meat production from lairage to chilling of the carcase was
developed. Three main factors were considered for each step: presence of a hazard, detection of the
hazard and actions undertaken as a result of detecting the hazard. Current MI requirements dictate
that green offal (including intestines and associated lymph nodes) must undergo visual inspection
and palpation. For this risk assessment PH, AH and AW risks associated with three scenarios have
been studied:
(i) current GO inspection regime;
(ii) only visual inspection; and
(iii) total absence of GO inspection.
The assessment aimed to produce a measure of the likelihood of a hazard to be present in a carcase
at chilling and to establish risk differences between the scenarios.
Data and supporting information necessary for this research were obtained from official databases,
official reports and scientific literature. Expert opinion was used to address information and data
gaps.
Conclusions
Effectiveness Assessment Tool
The results of the initial validation of the tool were satisfactory. It showed a good discrimination
capacity that allows for appropriate comparison of effectiveness among MI tasks. However, further
validation would confirm the suitability of the model for a greater number of hazards. The results so
far are promising and further work should be encouraged.
The assessment findings suggest that only 20 out of the 33 legally required MI tasks may be
contributing realistically to the detection of the hazards tested in this project. The outcomes on the
selected hazards were in line with the experts‟ expectations and experience.
A great constraint on the work was the lack of data and information to include in the model. It will
require a substantial amount of field-based research to obtain precise data.
Risk Assessment
The qualitative risk assessment for the three GO inspection scenarios showed that for the hazards
studied in this research – bTB, toxoplasmosis (in sheep), MAP, Salmonella (in pigs), CSF, hernia and
tail bites (in pigs) – the contribution of GO inspection was found to be of limited value because
lesions associated with these hazards are seldom manifested in GO alone or their detection is not
always followed by remedial action. Therefore, removal of this MI task would not make a substantial
difference to the detection of these hazards and to their consequent risks to PH, AH and AW.

Understanding the results
The findings of this research highlight the correlation between pathogens, animal health and welfare,
meat production and safety of food products. These relationships must be considered in order to
understand:
o which MI tasks have a significant impact on the protection of public health, animal health and
welfare.
o which MI tasks have a significant impact on the presence of hazards.
o whether the slaughterhouse is the best place to control certain PH, AH and AW risks.

The outputs of the project will help to assess the value of the current MI process and to identify areas
where improvements can be made to increase effectiveness while ensuring an appropriate level of
public health, animal health and welfare protection.
Section 3 : Achievements of Project Targets
SCIENTIFIC OBJECTIVES (from Scope of Work section SW1):

Objective 01
Create an inventory of hazards to human health, animal health and animal welfare related to
meat production and its related conditions. Identify available meat inspection tasks at the
slaughterhouse (including ante and post-mortem) for each of them.

Extensive literature review was conducted to identify all hazards (public health, animal health
and welfare) associated with meat production in the UK. Inspection data from FSA were also
consulted. Meat inspection practices at the slaughterhouse (as described in the relevant
European legislation) were mapped as well as their suitability to identify a selection of hazards
(the most relevant hazards). The focus of this review was on biological hazards; however, a
narrative review of chemical and physical hazards associated with meat production was also
carried out and it is included in the report.

Objective 02
Development of a qualitative approach to assess the relative effectiveness of inspection
activities. This will produce a scientifically valid assessment tool to evaluate effectiveness of
the various available meat inspection activities.

A computer based model has been developed that maps the meat inspection practices at the
slaughterhouse (ante and post-mortem). The model produces, by analysing numerical inputs
(sensitivity and positive predictive value), a qualitative score that indicates the inspection
task‟s capacity of detection of a specific hazard. It can be applied to public health, animal
health and animal welfare hazards.
For each hazard, the qualitative scores of the different tasks are comparable; the outcome can
be therefore understood as a “relative capacity of detection”.

Objective 03
Evaluate the suitability of each inspection task for a selection of hazards (for human health,
animal health and animal welfare).

The model has been applied to 7 hazards (3 for public health, 2 for animal health and 2 for
animal welfare). The model has been evaluated by different external experts involved in the
project and modified accordingly. Although initial validation has been achieved, the validation
should be expanded to include other hazards to make sure the model responds appropriately
to a great range of situations. A report on the activities undertaken as part of this objective
along with an electronic version of the model accompanies the final report.
Objective 04
Create a generic risk assessment model mapping all inspection tasks at the slaughterhouse.

Please refer to report N3 for information on the „risk pathway‟ assessment.

Objective 05
Qualitatively evaluate the level of risk for specific hazards associated with the current and
alternative green offal inspection activities.

Two modifications to the original proposal have been introduced. The pathway developed
under objective 4 was simplified in order to be used for objective 5. Specifically, for objective 5
we focused on activities that take place at the slaughterhouse (i.e. we did not evaluate risks at
the farm or during transport).
Secondly, the original proposal stated (objective 05. Task 02): “... the evaluation of the risk is
understood in this project as the probability of detecting the condition associated with a
specific hazard (...) and the consequences for public health, animal health and animal
welfare.” Our risk assessment evaluates the likelihood of a specific hazard being present at
the end of the slaughter line (e.g. chiller).
Instead of accurate measurement of consequences, we have made a general comment of
what implications will the presence of hazards in/on the carcase in the chilling room have for
public health, animal health and animal welfare. This has been done assuming that all
subsequent steps will not impact in the level of contamination of the carcase/meat.
Project MC1003

Outcomes and values of current ante- and post-
mortem meat inspection tasks
and
Assessment of benefit to public and animal health of post-mortem

inspection of green offal in red meat species at slaughter

Project Report N.1

Authors: Silvia Alonso, Lecturer in Veterinary Public Health
Nikolaos Dadios, Research Assistant
Neville Gregory, Professor in Animal Welfare Physiology
Katharina Stärk, Professor in Veterinary Public Health

Department of Veterinary Clinical Sciences, RVC

Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA
Tel: [phone] Fax: [phone] Email: [email protected]
Project MC1003 2010

Outcomes and values of current ante- and post-mortem
meat inspection tasks
Project code: MC1003

PROJECT REPORT N.1 (Objective 1) – Inventory of hazards to human
health, animal health and animal welfare related to meat production and
its related conditions. Identify available meat inspection tasks at the
slaughterhouse for each of them.

SCOPE OF STUDY
This report outlines the activities conducted and results obtained as part of the first
objective of the project MC1003. The scope of this first objective was to create an
inventory of hazards to public health (PH), animal health (AH) and animal welfare
(AW) related to meat production and to assess the extent to which the current meat
inspection tasks at the slaughterhouse address those hazards. The project focus is on
red meat production, and specifically cattle, pig and small ruminants.

BACKGROUND
Meat inspection (MI), comprising ante- and post-mortem inspection, represents a
fundamental control point for the various hazards associated with the meat
production chain. It was established in the nineteenth century, when it was
discovered that some serious human diseases originated in food animals and could
be transmitted to humans through the consumption of meat (Edwards, Johnston et
al. 1997). The aim of such inspection was to prevent transmission of infectious agents
from animals to humans by detecting sick animals or infected carcases and
preventing them from reaching the consumer. The underlying principle was that
animal diseases presented with macroscopic lesions in specific organs of the animal
and those were easily identifiable during carcase inspection (Pointon, Hamilton et al.
2000). Identification of such lesions was followed by appropriate measures to stop
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Project MC1003 2010

those animals or parts of the animals to get to the subsequent steps in the food chain
(Edwards, Johnston et al. 1997). Meat inspection practices have not changed much
since its inception and still rely heavily on the detection of macroscopic signs and
lesions in organs and carcases (Reg. (EC) 854/2004). In addition, it appears to be a
rigid and very prescriptive inspection (Gracey, Collins et al. 1999). It has been
transposed and use in areas and countries of great geographical distance, where
farming methods and animal diseases were very different to those in Europe
(Hathaway 1993).
Later, meat inspection practices started playing an increasingly important role in
protection of animal health and welfare. Inspection at the slaughterhouse is one of
the most suitable points along the food chain to collect a variety of data that can be
used not only for early identification of epidemics or emerging diseases but also to
guide the formulation of future policies regarding animal health on the national herd
(Gracey, Collins et al. 1999; Garcia, Gonzalez et al. 2003). Nevertheless, the primary
role of MI is still nowadays the protection of public health.
It is well recognized that the traditional meat inspection has accomplished a very
important role in protecting the public from meatborne zoonoses. Many diseases that
not very long ago were ravaging human health have now reduced their incidences,
and in some cases virtually disappeared from the main part of the European
continent (Edwards, Johnston et al. 1997). Illnesses that were affecting big parts of the
human population are now been seen only sporadically and are many times
imported from other countries. This is especially common with parasitic diseases that
are connected to unsanitary conditions in the human population and low meat
inspection standards (Sciutto, Fragoso et al. 2000; Garcia, Gonzalez et al. 2003).
Although meat inspection at the point of slaughter was only one part of a broader
process, it is well accepted that it represents an important one (Garcia, Gonzalez et al.
2003).
Despite the success of MI to contain major human health hazards, today new
threats seem to have become more prevalent. These new hazards, helped by the
modern, industrialised way of food processing and distribution, and the increased
mobility across the globe of a big part of the human population, can reach a greater
number of people and have very serious consequences. Examples are spongiform
encephalopathy agents, campylobacter, drugs residues and chemical contaminants.
While some of these hazards may cause clinical disease on the animal host, many
exist subclinically. As a result it is currently questioned to what extent the traditional
inspection practices are suitable to deal with these hazards (Pointon, Hamilton et al.
2000). Even more, experts have suggested that traditional meat inspection may
contribute to the spread of these agents (Edwards, Johnston et al. 1997; Pointon,
Hamilton et al. 2000).
3 Outcomes and values of current ante- and post-mortem meat inspection tasks – Report 1
Project MC1003 2010

Policy makers and stakeholders suggest the traditional meat inspection system at
the slaughterhouse is not fit anymore to protect the public against these diseases and
a radical overhaul and a new way of thinking is necessary (Edwards, Johnston et al.
1997; Mousing, Kyrval et al. 1997; Gracey, Collins et al. 1999; Pointon, Hamilton et al.
2000). The argument is based on the fact that, the diseases identifiable in traditional
MI rarely present a risk for the consumer. The real risk currently lies with the
invisible hazards(Mousing, Kyrval et al. 1997).
In order to evaluate the suitability of the current meat inspection practices to
protect public and animal health and animal welfare, risk assessment principles
should be applied in the identification and assessment of hazards, to make the most
effective use of limited existing resources (Pointon, Hamilton et al. 2000). A holistic,
or “farm to fork”, approach should be taken, that will focus on the most critical steps
in the identification of hazards from the farm till the final product (Desmarchelier,
Higgs et al. 1999).
The first part of this project, outlined in this first report, examines the extent to which
the most common meatborne hazards are suitable of being identified via the
traditional MI practices as outlined in Regulation (EC) 854/2004. The evaluation
includes public health, animal health and animal welfare hazards. A comprehensive
list of hazards is created, followed by a process of selection of those particularly
relevant to the meat production. In a second step, the tasks that a meat inspector is
legally required to carry out at the slaughterhouse are listed and then matched to
each of the hazards they are suitable to identify.

TYPES OF HAZARDS
The project looked at biological, chemical and physical hazards. Nevertheless, on the
bases of (a) the actual relevance for either animal and public health and animal
welfare and (b) the capacity of current meat inspection tasks, based primarily in
visual inspection, palpation and incision, to identify each of these types of hazards,
the research work presented in this report focuses primarily in biological hazards.
Some considerations in relation to physical and chemical hazards are provided in the
discussion session of this report.

4 Outcomes and values of current ante- and post-mortem meat inspection tasks – Report 1