In many parts of the tropics livestock such as cattle, pigs, and chickens are important sources of both food and income. However, the nutritional requirements of these animals often cannot be met by the marginal pastureland available. Typically, farmers make up the difference by purchasing bags of concentrated animal feed that contain grain, protein, and various necessary minerals and nutrients. The feed is expensive, though, which can lead farmers to overuse their pasture, causing the soil to erode and compact. As pastures become less productive, farmers then cut down trees to create new pasture, which leads in turn to further deforestation.
January 21, 2014