up to from the nearest pophole of the building is permissible provided that a sufficient number of shelters and drinking troughs within the meaning of that provision are evenly distributed throughout the whole open-air run with at least four shelters per hectare. Otherwise, egg farming in EU is classified into 4 categories: Organic (ecological), Free Range, Barn, and Cages.) The mandatory labelling on the egg shells attributes a number (which is the first digit on the label) to each of these categories: 0 for Organic, 1 for Free Range, 2 for Barn and 3 for Cages. There are EU regulations about what free-range means for laying hens and broilers (meat chickens) as indicated above. However, there are no EU regulations for free-range pork, so pigs could be indoors for some of their lives. In order to be classified as free-range, animals must have access to the outdoors for at least part of their lives. United Kingdom Pigs: Free-range pregnant sows are kept in groups and they are often provided with straw for bedding, rooting and chewing. Around 40% of UK sows are kept free-range outdoors and farrow in huts on their range. Egg laying hens: Cage-free egg production includes barn, free-range and organic systems. In the UK, free-range systems are the most popular of the non-cage alternatives, accounting for around 57% of all eggs, compared to 2% in barns and 2% organic. In free-range systems, hens are housed to a similar standard as the barn or aviary. Free-range rearing of pullets: Free range rearing of pullets for egg-laying is now being pioneered in the UK by various poultry rearing farms. In these systems, the pullets are allowed outside from as young as 4 weeks of age, rather than the conventional systems where the pullets are reared in barns and allowed out at 16 weeks of age Meat chickens: Free-range broilers are reared for meat and are allowed access to an outdoor range for at least 8 hours each day. RSPCA standards state that in order for chickens to be free range, there must not be more than 13 chickens per square meter. Free-range broiler systems use slower-growing breeds of chicken to improve welfare, meaning they reach slaughter weight at 16 weeks of age rather than 5–6 weeks of age in standard rearing systems. Turkeys: Free-range turkeys have continuous access to an outdoor range during the daytime. The range should be