Use of Animal-based Measures to Assess Welfare of Broilers
Animal-based measures (ABM) can be used effectively in the on-farm evaluation of broiler welfare in relation to laws, codes of practice, quality assurance schemes, management and also partly for ante-mortem inspection, according to a new report for the European Food Safety Authority.Some Animal-based measures can also be taken post-mortem at the slaughterhouse.
The report says that non-animal-based measures can be used when the association between them and the welfare outcome is strong and when they are more efficient than animal-based measures as a means to safeguard welfare.
They can also be useful predictors of welfare in broilers.
The study was carried out following a request from the European Commission to the Panel on Animal Health and Welfare to deliver a Scientific Opinion on the use of animal-based measures to assess the welfare of broilers.
The research was to be carried out in relation to two key areas in the Community Action Plan (2006-2010) on the Welfare of Animals:
- the first concerns upgrading existing minimum standards for animal protection and welfare, and
- the second the introduction of standardised animal welfare indicators.
The recently adopted EU Strategy for the Protection and Welfare of Animals (2012–2015) also highlights that the possibility of using scientifically validated outcome-based indicators complementing prescriptive requirements in EU legislation will be considered when necessary.
Animal-based measures such as panting, low mobility, high numbers of emaciated birds or high mortality have been used by veterinarians and farmers effectively for many years in the evaluation of the health and welfare of broiler flocks on-farm as well as by scientists to measure the responses of animals as indicators of their welfare.
However, assessment in relation to quality assurance schemes and even the new EU broiler directive focuses mainly on measures of the environment (resources) or management (practices), in other words, on risk factors rather than on their consequences for the animal.
A European Union (EU) financed project called Welfare Quality® has been influential in developing a standardised system for the assessment of animal welfare on-farms.
In line with the European Commission’s intention to adopt a more systematic outcome-based approach to animal welfare, the Welfare Quality® project focused on animal-based measures and produced a welfare-outcome assessment protocol for several species, including broilers.
The concepts of animal welfare used in the Welfare Quality® project and EFSA Scientific Opinions overlap considerably, confirming general agreement in the scientific community concerning the definition of animal welfare.
The research team said that the challenge in this Opinion was to merge the risk assessment approach of the EFSA Scientific Opinions on the welfare of broilers with the welfare assessment approach of the Welfare Quality® project, as well as other related research projects on broiler welfare.
Animal-based measures can be effectively used to evaluate the welfare of broilers in relation to laws, codes of practice and management. Many of these are also appropriate for ante-mortem or post-mortem inspection of animals at the slaughterhouse.
The study concluded that the Welfare Quality® Broiler Protocol covers the majority of the main factors identified in the EFSA Scientific Opinion on broilers (EFSA, 2010a) and that animal-based measures are very useful to determine whether or not the improvements in welfare intended by the recommendations in the EFSA Opinion have been achieved.
However, it noted that some of the factors (e.g. poor ventilation) lack specificity, which means that there are several outcomes that could be measured, and also sometimes an animal-based measure (e.g. lameness) lacks specificity, which means a welfare outcome could have one or several causes.
Thus, the links between factors (resources and management) and their welfare consequences (using animal-based outcome measures as indicators) is far from simple.
Nevertheless, a “toolbox” of valid and reliable animal-based measures is described, from which the most appropriate measures or combination of measures can be selected. The selection will depend on which welfare outcomes (consequences) are to be assessed and the reason for wanting to assess them (e.g. whether part of a management/breeding strategy or to enforce legislation).
Several animal-based measures listed in this Scientific Opinion are already fully developed and have a high potential for automation in commercial practice, as is already the case in some countries (e.g. detection and score of foot-pad dermatitis) and injury scores.
Other animal-based measures have been widely used for a longer time (e.g. automatic weight gain monitoring, feed and water consumption at flock level).
Such data from the standardised use of some of these measures, in a variety of real life situations, could be collected on a regular basis and the database analysed to describe these complex associations.
This would continually improve the selection process of appropriate animal-based measures for different contexts. It would also pave the way for a move towards quantitative risk assessment of broiler welfare, the research team said.
There are several ways in which animal-based measures can be and are used to assess the welfare of broilers.
Many of the animal-based measures that are referred to in the opinion are related directly or indirectly to the health and production of broilers as well as to specific environmental conditions (e.g. high temperatures, heat stress, panting).
Most often, the indicators are used to identify animals whose welfare is already poor.
Animal-based measures (such as panting), together with automatic surveillance systems, could be used to identify that welfare is being affected so that changes can be made before the consequences become too severe (e.g. early recognition of panting and increase of ventilation rate to avoid deaths attributable to heat stress).
The report says that in this way, in monitoring and surveillance systems some animal-based measures may be useful, not only because they can indicate current welfare problems in the flock, but also because they can serve as a tool for early detection of consequences that may indicate a potential, future, negative situation.
Although animal welfare issues can be addressed using animal-based measures, several situations in which a non-animal-based measure is preferable in practice have been identified. The most common reason is that there is a resource-based measure easier to record (e.g. elevated ambient temperature, high levels of atmospheric ammonia) or that the animal-based measure is too time-consuming to collect or requires specific skills or analysis. In some cases, no single measure is fully adequate.
The greatest potential to improve animal welfare in broiler production is seen in the application of a range of appropriate animal-based measures to be assessed and documented in the slaughterhouse in the course of visual meat inspection.
Such measures can also be used to document welfare changes over time.
The research team recommends that this should include the development of automatic monitoring and assessment systems as well as both initial and ongoing training of assessors in the field and in the abattoir to ensure valid and reliable welfare measurement.
There are currently no animal-based measures to use as welfare outcome indicators on-farm or in the slaughterhouse to assess the issues of pain, frustration, boredom and other positive and negative emotional states in the standard broiler.
The study says that research in this area is lacking.
It shows that there are limited management options to prevent the negative consequences of factors arising from most housing-related problems with when the flock is still in the house.
The same applies to negative effects arising from genetic selection.
Changes in breeding goals may take a long time to improve welfare as indicated by animal-based measures noted at the farm level, the report says. Some factors, such as changing the litter or stocking density, can be made between flocks whereas others, such as changing the ventilation system, remain difficult even between flocks.
The probability of a feature in the environment becoming a hazard depends on the characteristics of the animal, including its genetics and its age. Therefore, animal-based measures, describing the consequences of animal exposure to factors, are the preferred indicators of animal welfare and should be used whenever possible in future EFSA risk assessments of broiler welfare, the EFSA report says.
The study team has called for more work to be carried out including more systematic herd monitoring and surveillance programmes in the broiler industry.
The report says that data on animal-based welfare-outcome indicators can be collected on-farm or at the slaughterhouse, provided that there is adequate traceability, either by observation or inspection of the animal, or from other sources, such as meat inspection, disease-reporting systems and production records. Furthermore, although welfare is a characteristic of the individual animal, many of the animal-based measures in broilers are in fact reported at the flock level.
It concludes that benchmarking is increasingly used to track changes within the same farm over time or, more often, to compare farms. When the same animal-based measure is compared among farms with similar housing systems and management practices, it facilitates the identification of those farms that are outside the normal range of variation and this information is also relevant to the assessment of broiler welfare.
Further Reading
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July 2012