The Model Code of Practice for the Welfare of Animals - Domestic Poultry, sets out space requirements for free range hens. Both indoor and outdoor space is defined. It is important to know that if you are locking your birds in at night, the indoor space requirements must be complied with. Your good intentions could actually be detrimental to hen welfare if you are confining them in an inappropriately small space especially if there is little ventilation, no cooling system or fans. Overcrowding can also lead to behavioural problems such as feather pecking.
Section 3 of the Model Code defines Space Allowances and special attention should be paid to clause 3.2 which states:
"The stocking density will also depend on the quality and type of housing and the capacity to achieve and maintain acceptable levels of temperature, humidity, air exchange, removal of noxious gases and lighting..."
Section 6 Ventilation states in clause 6.3 that:
"The housing facilities of free range hens must be designed to ensure adequate airflow and temperature control at maximum stocking densities when birds cluster or perch at night or during extreme weather conditions."
Appendix 2 of the Model Code sets out the indoor stocking density for layer hens and meat birds in clause A2.1.2. It also states that:
"These maximum densities may be used only if there are cooling systems and ventilation fans in place to ensure temperature control during extreme conditions. Lower stocking densities should be targeted, and will frequently be lower than the maximum stated here."
The PROOF Standards for Poultry require an indoor stocking rate of 16kg of bird weight per square metre, or, approximately 8 hens per square metre. This is a lower density that the maximum allowed in the Model Code of 30 kg of bird weight because mobile outdoor sheds are generally not fitted with cooling systems, ventilation systems or fans and therefore allowances must be made to ensure that temperature, humidity, air exchange and removal of gases is optimal for the welfare of the hens. Small sheds and caravans can heat up quickly. Housing needs enough floor space to allow air movement around each bird to lower its temperature and the humidity in such a close environment. Measure the floor area of your hen house but don't include the perches if they are over the floor area (birds below will be fouled on). You cannot expect the hens to spend the entire time they are locked up to remain confined to a perch. Each system will be assessed on its own merits as sheds, caravan and mobile housing vary greatly between farms. Compliance is much less complicated when birds are not confined indoors.
If you feel it is necessary to house your hens at night for protection, you must consider the type of housing you have and if it is in the best interests of the hens to confine them to it or, will you find yourself non-compliant with the Model Code? Does the housing have adequate roof ventilation, what is it constructed of, are you expected the birds to only use perches for the duration of confinement, is the flooring going to prevent foot and leg injuries, is there feed and water available? Is your farm management good enough to ensure that the hens are let out at daybreak every day? Would you want to be locked in there all night?
There are other options to protect your hens: