Feeding and watering is also automated. Feed can include the recyled remains of unwanted male chicks and other animal products as well as growth-promoting antibiotics, yolk colourants and other additives. Hens are taken from breeding farms when 18-20 weeks old and put into cages, usually with four other birds. Each hen can produce 300 eggs per year. This compares with only 12-20 eggs produced each year by their wild ancestors.
Hens are so crowded that they are unable to move freely or flap their wings.
After twelve months, the hens egg-laying ability starts to decline. Hens are then considered spent and so are slaughtered and used in baby foods, pet foods, soups, pies and other processed foods. The natural lifespan of a hen is about 5 or 6 years. A single cage housing five birds averages only 40 x 55 cm in size. This legislation currently only covers cages built after January 1st 1988.