A recent article (19 Sep 2010) in the Italian business newspaper Il Sole 24 Ore shows us three chickens and asks which one we would like to have eggs from. The photograph of the three chickens suggests that the last one, perhaps raised in a very small cage, is the least healthy and therefore we would choose the eggs from the first two chickens. In fact the first two were raised in indoor cages, while the last is “free range.” Why the difference? First the facts:
Chicken A: Raised with four other hens in a cage that measures 60cm by 47cm, meaning there is 540 square centimeters per bird. Both water and food are available at all times.
Chicken B: Raised with forty-nine other hens in a cage that is 300cm wide by 200cm tall by 480cm deep, giving a space 2,570 square centimeters per bird. Water and food are available at all times, as are nests and sand for sand baths (to rid the birds of parasites).
Chicken C: Raised with 11,999 other chickens in a single cage that is seven hundred square meters. Every day from 11 in the morning until dusk the chickens are given access to a four hectare open air where they can eat, drink, and take sand baths.
Why then the difference in plumage? The article describes the native conditions of the ancestor of the modern chicken, the jungle fowl of Southeast Asia. They lived in the jungle understory in groups of between twenty and thirty birds and had a rigid hierarchy, established by aggressive pecking (the proverbial “pecking order”). It seems that despite the seemingly natural conditions of the free range birds, the inability to establish that hierarchy is extremely stressful. Every chance encounter–and there are hundreds if not thousands a day–leads to pecking to establish a hierarchy that the chickens’ brains are not complex enough to remember. ZN
Grazie ad Anna Selberg per la segnalazione.