The Pasture is one of the earliest improvements available. Its most important use is to give access to the first strategic resource in the game: Horses Horses. But it is used much more frequently to improve the more common Sheep Sheep and Cattle Cattle resources, giving them a much-needed Production boost.
Along with the Farm and the Camp, the Pasture's Housing bonus is an important way to ensure Population growth in the earliest stage of the game. At the same time, adopting the God of the Open Sky Pantheon will speed up your social progress greatly, thanks to the added Culture per Pasture.
Since it is a lot easier to keep track of livestock if they aren’t running loose across the countryside, it wasn’t long after grazing animals were domesticated that a lazy shepherd devised a fence for keeping them in a pasture. Even those pastoralists who practiced transhumance had crude pastures at each end of their seasonal journeys. Pastures (not to be confused with meadows) are typically grazed throughout the summer, and may be purposely planted or simply fenced-off rangeland. The fences can be made of almost anything that will keep the livestock in and the local predators (animal or human) out: rock and stone, posts and rails, thorny brush, barbed wire, or electric wire. In most places, land ownership was tied to fenced pasturage, as in feudal societies or those progressive ranchers in the American West.