Conclusion and recommendations
A major achievement of the LayWel project has been the compilation of the database. Its structure and the collaborative discussions that led to this have been extremely valuable, and will undoubtedly influence and improve the design of future scientific studies of laying hen welfare. It has been extremely beneficial that LayWel partners representing seven countries, and with contacts in other EC countries, have worked together on designing and contributing data to the database. This will ensure a much more unified approach in the future and could lead to more collaborative projects.
The carefully structured layout of the database has enabled gaps in data availability to be clearly identified and has also indicated the type and format of data that future studies might collect. Additionally future methodology is likely to be more uniform.
In order to produce statistically valid models, more data are needed in most areas and thus the database ought to be expanded at least until sufficient data are entered to enable this. Data from in excess of 100 treatments (flocks) are generally required for modelling and this quantity could potentially be gathered within three years for many parameters.
We recommend that:
- financial support is given to maintaining the database for at least 3 years so that future work may be included in it and so that modelling of the data is valid
- all scientists studying laying hen welfare consider expanding the number of indicators used in future work so that individual studies measure a greater range of indices (e.g. including physiology and behaviour)
- more data are collected for areas of limited data availability(as indicated in Tables 7.7 and 7.8)
2. Integument scoring
A second major achievement of the project has been the development of feather scoring and integument (head and feet) scoring systems together with comprehensive sets of photographs. This has included developing methodology for transforming data from different scoring systems, which makes comparing different studies much easier.
We recommend:
- the integument scoring systems are widely adopted, as they represent the consensus of the LayWel partners and an integration of several previous systems
- integument scoring is routinely and frequently carried out on all farms to assist in the detection of damaging pecking, which is currently a widespread welfare problem
3. Behaviour
The most important enrichment for hens is the provision of a discrete, enclosed nest site. More scientific research is needed to determine whether perching is a behavioural priority and the extent to which hens value dustbathing and need a substrate, but there is strong evidence that both are behavioural needs. The presence of apparently purposeless behaviour or of high levels of aggression or redirected behaviours such as feather pecking and cannibalism are indicators that the housing system is not satisfactory for bird welfare.
Feather pecking is still a very predominant welfare problem in commercial flocks in non cage systems with a prevalence of between 40 and 80%. The prevalence of cannibalism is lower but with up to 20% of flocks were affected in one survey and up to 40% in another.
In furnished cages about 40 to 50% of the hens perched during the day and 80 to 90% during the night. The use of perches at night was higher in the smaller compared to medium or larger furnished cages, which could be due to design differences. The use of the dustbathing area was very different for the LayWel data from four models of furnished cages. Birds reared on floor had a slightly higher dustbathing activity than cage reared birds.
We recommend that:
- more research is carried out to determine the influence of rearing system design on behaviour during lay and on the nature of and timing of provision of key resources such as foraging mediums, perches, nestboxes etc.
- all hens be provided with discrete, enclosed areas for egg laying
- perches are provided, and that more research and development is carried out to optimise their design and use by hens
- assessment of substrate quality in different laying hen housing systems should include recording of dustbathing behaviour activity and quality and foraging behaviour (see WP4 for methodology)
- more research is carried out to determine optimum substrates for foraging and for dustbathing (in particular environmentally-friendly alternatives to peat, which is a preferred choice for dustbathing)
- more research is carried out to determine optimum design of dustbathing areas in furnished cages
- suitable genotypes with minimal tendencies for aggressive pecking are selected for use in group housing systems
4. Health
We recommend that:
- both industry and research scientists direct maximum effort to establishing the causes of outbreaks of feather pecking and designing housing systems and management strategies to minimise this risk
- causes of the high levels of fractures during lay are determined together with strategies for reduction as a matter of priority
- hens are examined (and scored) for bumble foot regularly, but especially at 35-45 weeks of age