Laying hens - farming (egg production systems)

Around 35 million commercial egg-laying hens were kept in the UK in 2012.

After hatching, the chicks are transferred to a pullet-rearing farm where they stay until they are about 16 weeks of age. ‘Pullet’ is the term for a young hen before she starts laying eggs. Pullets destined for non-cage systems will typically be reared in large barns, sometimes with access to an outdoor range, while many pullets destined for cages will be kept in cages from one day old.

Just before they are ready to start laying eggs the birds are then moved to a laying unit where there are facilities for egg collection. Three different types of systems can be used to house hens on a laying unit - battery cages, barn or free-range (which may also be organic).

Free-range
The majority of free-range hens on commercial farms live in buildings similar to the barn system, but with the addition of access to the outside through openings called ‘popholes’. EU laws require that free-range hens must always have access to an outside area with adequate vegetation during the daytime.

The RSPCA welfare standards permit no more than 2,000 birds per hectare of range over the life of the flock, while allowing up to 2,500 per hectare for periods of time. This allows resting of various areas and active management of the range area in order to maintain vegetation quality and minimise risk of disease. This, along with shade and shelter on the range, helps to encourage hens to enjoy the area fully.
  

Barn systems
In barn systems hens are not kept in cages, and have the freedom and space to move around, stretch and exercise within a building. Perches are also provided for the hens to roost on, as well as material to dustbathe and forage in, and nest boxes where they can perform their nesting behaviours and quietly lay their eggs. Some non-cage housing systems are ‘multi-tier’, providing additional levels above the ground, which the birds can use to move up and down.

Battery cages
Since a change in law came in to force on January 1st 2012 battery cages throughout Europe now offer 50 square centimetres more usable space per bird compared to the previous conventional barren battery cages, but in total this is still less than the size of an A4 piece of paper each. These so-called ‘enriched’ battery cages also have to provide limited facilities for perching, nesting and scratching, but we still do not believe that they provide for the full behavioural and physical needs of the birds.

Each wire cage typically houses around 80 hens and there may be as many as 9 rows of cages stacked on top of each other from the floor level in one building, with walkways for the stock-keepers in between.  

In 2012 the proportion of eggs produced in these different systems in the UK was:

• 49 per cent of eggs produced in battery cages*
   
• 4 per cent in barn systems*
   
• 48 per cent in free-range systems (of which 3 per cent were organic systems)*. 

More and more people are choosing to buy eggs from hens kept in free-range or barn systems when they buy boxes of eggs. 10 years ago 31 per cent of eggs in the UK were produced by hens kept in these systems, but this has now risen to 51 per cent.

However, although consumers are buying more free range and barn eggs when we buy boxes of eggs, about 80 per cent of eggs used as ingredients in products like mayonnaise, cakes and sandwiches are still from hens kept in cages.

All commercially reared hens are typically kept until they are 72 weeks of age, when egg production and quality declines.

source:
www.rspca.org.uk