Southdown sheep no longer economical and smaller flocks averaged only 135 ewes apiece. The use of artificial fertilizers had gained ground, and the combine-drill, which sowed grain seeds and fertilizer together, rendered close-folding by sheep unnecessary. Gradually surrendering to basic arable farming changes, the Southdown became largely a grassland breed. During the interwar years, the United Kingdom was known for farm animal breeding, and pedigreed Southdowns were still being exported to most parts of the world, especially New Zealand. In 1937, the number of exported Southdowns reached 459 head. During the Great Depression, a severe and prolonged fall in the prices of
Rare breed (agriculture) Rare breed (agriculture) In modern agriculture, a rare breed is a breed of poultry or livestock that has a very small breeding population, usually from a few hundred to a few thousand. Because of their small numbers, rare breeds may have a threatened conservation status, and they may be protected under regional laws. Many countries have organizations devoted to the protection and promotion of rare breeds, for which they each have their own definition. In botany and horticulture, the parallel to rare animal breeds are heirloom plants, which are rare cultivars. There are several definitions of "breed" and "rare breed".