Housing Systems for Laying Hens
July 3, 2018
The CVMA holds that primary consideration should be given to the welfare of the birds when housing systems for laying hens are adopted. To provide good health and welfare for laying hens, the CVMA supports the evaluation and implementation of both enriched/furnished cage systems and non-cage colony systems that are compatible with good standards of animal welfare.
- The 2017 National Farmed Animal Care Council (NFACC) Code of Practice requires that traditional battery cage systems be phased out;
- The CVMA considers that enriched/furnished cage systems as well as cage-free systems should be considered as viable options;
- Enriched/furnished cage systems were developed on the basis of scientific research to meet the behavioural needs of laying hens while retaining the health and welfare advantages of caging;
- The CVMA encourages further research and development on housing systems for laying hens;
- The focus of the CVMA position on housing systems for laying hens is the welfare of the birds and the necessity when adopting a housing system to continue to consider all options that are compatible with good standards of animal welfare.
The National Farmed Animal Care Council (NFACC) Code of Practice for the care of laying hens (1) contains requirements that will phase out the traditional battery cage system and producers will need to adopt an alternative housing system. The options for producers are an enriched/furnished cage system or a non-cage colony system (including systems such as free-range, free-run, barn, aviary or litter).
The Code, the associated scientific review (2) and other academic evaluations (3,4) recognize that all housing systems for laying hens have advantages and disadvantages.
The CVMA acknowledges that it is a legitimate ethical position for individuals and organizations to lobby for and state their preference for hens to be housed in “cage-free” systems. However, from a scientific and veterinary perspective on animal welfare, the CVMA considers that enriched/furnished cage systems also offer an option that is compatible with the provision of good standards of health and welfare (4).
Enriched/furnished cage systems were developed on the basis of scientific research to meet the behavioural needs of laying hens while retaining the health, welfare advantages of caging. Although, non-cage systems provide hens with a greater opportunity to express their full behavioural repertoire, especially foraging and exercise (leading to improved bone strength), large group sizes in non-cage systems can be associated with increased risk of injury and mortality from feather pecking, cannibalism and smothering. The type of housing system also affects the risks of animal and zoonotic diseases and exposure to poor physical environmental conditions (3-6).
The focus of the CVMA position on housing systems for laying hens is the welfare of the birds, and the need for continued consideration of all options that are compatible with good standards of animal welfare (6,7). The CVMA encourages further research and development on housing systems for laying hens that meet the welfare requirements of the birds, and on breeding to reduce the risk of injurious behaviours that can occur when hens are kept in large groups (8).
- NFACC. 2017. Code of Practice for the Care and Handling of Pullets and Laying Hens. Available from: https://www.nfacc.ca/codes-of-practice/poultry-layers Last accessed October 17, 2017.
- Widowski TM, Classen H, Newberry RC, Petrik M, Schwean-Lardner K, Cottee SY and Cox B. Code of Practice for the Care and Handling of Pullets, Layers, and Spent Fowl: Poultry (Layers). Poultry (Layer) Code of Practice Scientific Committee, Review of Scientific Research on Priority Issues 2013. Available from: http://www.nfacc.ca/resources/codes-of-practice/poultry-layers/Layer_SCReport_2013.pdf Last accessed October 17, 2017.
- LayWel 2004. Overall strengths and weaknesses of each defined housing system for laying hens, and detailing the overall welfare impact of each housing system. In: Welfare implications of changes in production systems for laying hens (www.laywel.eu). Available from: http://www.laywel.eu/web/pdf/deliverable%2071%20welfare%20assessment.pdf Last accessed October 17, 2017.
- Lay DC, Fulton RM, Hester PY, Karcher DM, Kjaer JB, Mench JA, Mullens BA, Newberry RC, Nicol CJ, O'Sullivan NP, Porter RE. Hen welfare in different housing systems. Poultry science, 2011;90:278-294. Available from: https://doi.org/10.3382/ps.2010-00962 Last accessed October 17, 2017.
- Weeks CA, Lambton SL, Williams AG. Implications for welfare, productivity and sustainability of the variation in reported levels of mortality for laying hen flocks kept in different housing systems: a meta-analysis of ten studies. PLoS ONE 2016;1:e0146394. Available from: https://doi.org/10.1371/journal.pone.0146394 Last accessed October 17, 2017.
- Mench JA, Sumner DA, Rosen-Molina J. Sustainability of egg production in the United States-the policy and market context. Poult Sci 2011;90:229-240. Available from: https://doi.org/10.3382/ps.2010-00844 Last accessed October 17, 2017.
- Weary DM, Ventura BA. von Keyserlingk MAG. Societal views and animal welfare science: understanding why the modified cage may fail and other stories. Animal 2016;10:309-317. Available from: https://doi.org/10.1017/S1751731115001160 Last accessed October 17, 2017.
- Rodenburg TB, Turner SP. The role of breeding and genetics in the welfare of farm animals. Animal Frontiers 2012;2:16-21. Available from: https://doi.org/10.2527/af.2012-0044 Last accessed October 17, 2017.
((Adopted July 2018))