Sardinia is home to nearly 4 million sheep, almost half of the entire Italian assets and that makes the island one of the areas of the world with the highest density of sheep along with some parts of UK and New Zealand (135 sheep every square kilometer versus 129 in UK and 116 in New Zealand). Sardinia has been for thousands of years specializing in sheep breeding, and, to a lesser extent, goats and cattle that is less productive of agriculture in relation to land use. It is probably in breeding and cattle ownership the economic base of the early proto-historic and monumental Sardinian civilization from Neolithic to the Iron Age.