Many of the great sheep countries of the world are dry, semi-arid areas. Most breeds of sheep flourish best in this sort of terrain. They are susceptible to fewer hazards of health or parasites where the climate is dry. But in those same regions it is neither natural nor common to find green pastures. Green pastures were the product of tremendous labour, time, and skill in land use. Green pastures were the result of clearing rough, rocky land; of tearing out brush and roots and stumps; of deep ploughing and careful soil preparation; of seeding and planting special grains and legumes; of irrigating with water, and husbanding with care the crops of forage that would feed the flocks. Green pastures are essential to success with sheep. A hungry, ill-fed sheep is ever on it's feet, on the move, searching for another scanty mouthful of forage to try and satisfy its gnawing hunger. Such sheep are not contented, they do not thrive. But because of their own peverseness sheep often prefer to feed on the barren ground around them. They will at times actually choose inferior forage.