Housing Systems For Laying Hens

When assessing the welfare issues of housing systems for laying hens, the “five freedoms” (FAWC Press Statement, 1979) are a good, although not perfect, indicator when evaluating the pros and cons of each system. The “five freedoms” are freedom from hunger and thirst; freedom from thermal and physical discomfort; freedom from pain, injury and disease; freedom from fear and distress; freedom to exercise most normal patterns of behaviour.

The most common housing systems for hens in industrial farming are conventional cages, enriched cages, non-cage housing (barn and aviary) and free range. Conventional cages were banned in the EU in 2012 due to welfare issues including the restriction of natural behaviours, cage-related injury and feather pecking (AVMA, 2017), although the “top three egg-producing countries (China, the United States of America, and India) still rely heavily (over 90%) on battery cages for egg production” (UFAW, 2016). It is evident that suffering is greater in battery cages than in well managed alternative systems (Appleby, 1991).

Enriched or furnished cages provide more space for each bird and also feature a perch, nest box/area and a litter or scratch area (AVMA, 2017). Enriched housing allows the birds more freedom to exercise patterns of normal behaviour compared to conventional cages but this also varies depending on the layout and amount of space for each bird. Dietary health is easier to control in confined housing and mortality rates are lowest in enriched housing. The main disadvantage is that furnishing in the cage can be poorly designed or malfunction causing injuries, harbouring disease or sparking aggression.

Barns are non-cage housing systems and are large sheds in which hens are housed on the floor, aviaries are similar but also have multi-tiered levels and perches. They both normally provide nest boxes and litter. There are advantages such as more freedom to roam but the disadvantages include an increase in the transmission of disease, high numbers of keel bone fractures, an increase in the risk of pecking and pecking mortality depending on group size and housing containing litter systems show an increase in levels of ammonia (The welfare aspects of various systems of keeping laying hens, 2005).

Free-range housing provides the birds with some access to indoor and outdoor areas meaning they have more opportunities to exercise normal behaviours and feather conditions are generally improved compared to cage and non-cage housing. Although the birds have a more natural environment, the use of an outdoor area exposes them to poor weather conditions, predators, toxins and diseases. Generally, free-range housing systems show higher mortality rates compared to any cage systems (Burch, DGS, 2012).

Organic housing systems are similar to free-range but standards can vary. According to the Soil Association, their certified organic farms are required to provide housing systems for laying hens with lower stocking densities, more exits from the hen house to the outdoor area to encourage ranging and they also prohibit beak trimming as they acknowledge feather pecking can be avoided by supplying a stimulating environment for the birds (2017). A study on the welfare of organic laying hens in Denmark showed differences in the welfare and mortality rates of the hens on different farms were due to the design of the housing, management of the flock, type of cover and vegetation of the outdoor area (Hegelund, Sørensen and Hermansen, 2006).

I believe well managed free-range systems can provide the best psychological and physical animal welfare. Good design of both the indoor and outdoor space to protect the hens and prevent injury and disease is necessary. Positive results with this type of housing require effort from the farmers to maintain the housing system and provide high standards of hygiene for the birds. Research has shown that some producers have been able to keep free-range hens with high productivity, a low mortality rate and good feather conditions (Hegelund, Sørensen and Hermansen, 2006). Management, housing design, breed, and rearing conditions are all important factors when considering optimal hen welfare and productivity (Lay et al., 2010).

The main barriers to implementing free-range housing systems are costs and farmer management skills. To overcome these barriers, further research into the ideal environment for laying hens, and for different breeds, is needed. Farmers also need to be educated on the importance of welfare and the benefits it can have to production in the long-term. The ban on battery cage systems in the EU has had a positive impact on the psychological welfare of hens but has shown an unexpected increase in fractures of the keel bone in hens (Nasr, Nicol and Murrell, 2012) so this system is not satisfactory. A ban on cage systems would be needed to implement widespread use of free-range systems with training on how to ensure high standards of welfare to the hens.

There are still many welfare issues that can arise from free-range and organic farming if housing is not maintained properly and other considerations such as handling, I hope that one day we will see the end of the egg industry altogether.

References

Appleby, M. (1991). DO HENS SUFFER IN BATTERY CAGES?. [ebook] Compassion in World Farming. Available at: https://www.ciwf.org.uk/includes/documents/cm_docs/2008/d/do_hens_suffer_in_battery_cages_1991.pdf [Accessed 2 Oct. 2017].

AVMA. (2012). Welfare Implications of Laying Hen Housing. [online] Available at: https://www.avma.org/KB/Resources/LiteratureReviews/Pages/Welfare-Implications-of-Laying-Hen-Housing.aspx [Accessed 1 Oct. 2017].

AVMA. (2010). Welfare Implications of Induced Molting of Layer Chickens. [online] Available at: https://www.avma.org/KB/Resources/LiteratureReviews/Pages/Welfare-Implications-of-Induced-Molting-of-Layer-Chickens.aspx [Accessed 2 Oct. 2017].

Farm Animal Welfare Council Press Statement. (1979). [online] Available at: http://webarchive.nationalarchives.gov.uk/20121010012427/http://www.fawc.org.uk/freedoms.htm [Accessed 2 Oct. 2017].

gov.uk. (2007). Opinion on Enriched Cages for Laying Hens. [online] Available at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/325142/FAWC_opinion_on_enriched_cages_for_laying_hens.pdf [Accessed 2 Oct. 2017].

Green, A., Wesley, I., Trampell, D. and Xin, H. (2007). Air Quality and Hen Health Status in Three Types of Commercial Laying Hen Houses Paper. ASABE Paper Number: 074119.

Hegelund, L., Sørensen, J. and Hermansen, J. (2006). Welfare and productivity of laying hens in commercial organic egg production systems in Denmark. NJAS - Wageningen Journal of Life Sciences, [online] 54(2), pp.147-155. Available at: http://www.sciencedirect.com/science/article/pii/S1573521406800187 [Accessed 4 Oct. 2017].

Lay, D., Fulton, R., Hester, P., Karcher, D., Kjaer, J., Mench, J., Mullens, B., Newberry, R., Nicol, C., O'Sullivan, N. and Porter, R. (2010). Hen welfare in different housing systems. Poultry Science, [online] 90(1), pp.278-294. Available at: http://www.poultryscience.org/docs/ps_962.pdf [Accessed 2 Oct. 2017].

Nasr, M., Nicol, C. and Murrell, J. (2012). Do Laying Hens with Keel Bone Fractures Experience Pain?. PLoS ONE, 7(8), p.e42420.

Soil Association. (2017). Organic vs Free-Range Eggs - What's the Difference?. [online] Available at: https://www.soilassociation.org/blogs/2017/february/organic-vs-free-range-eggs-whats-the-difference/ [Accessed 4 Oct. 2017].

The welfare aspects of various systems of keeping laying hens. (2005). EFSA Journal, [online] 3(3), p.197. Available at: http://onlinelibrary.wiley.com/doi/10.2903/j.efsa.2005.197/epdf [Accessed 1 Oct. 2017].

UFAW. (2016). Keel Damage in Laying Hens - UFAW. [online] Available at: https://www.ufaw.org.uk/why-ufaws-work-is-important/keel-damage-in-laying-hens [Accessed 2 Oct. 2017].