“By endurance we conquer”: fat tailed sheep in the twenty-first century

Abstract

In the temperate world, sheep are usually classified under two categories: wool and hair, where the latter are, in most cases, considered a relic of medieval times and not suitable for contemporary commercial sheep production. Additionally, in temperate countries, the sheep world is usually in black and white, as no other colors or mixing are commonly found. Interestingly, hair breeds are very adaptable to harsh environments like the churra breeds of the Iberian Peninsula or the Scandinavian hair breeds that thrive respectively in cold mountain ranges and sub-arctic islands. In the Tropics, however, the ovine world changes considerably: sheep have often (short) hair that tends to shed with changing seasons, and wool sheep are indeed a rare oddity. Additionally, tropical sheep are present in a vast array of coat-color patterns that eclipse the monochromatic nature of their relatives of temperate (mostly European) relatives. Besides these features, tropical sheep have a very distinctive and particular trait: the fat tail and/or fat rump, and are generally described as fat-tailed sheep (see Fig. 1). This morphological feature is characterized by an accumulation of fat mainly at the level of the hind quarters in varied shapes and volumes, and it is assumed to have similar physiological roles as those of the zebu or camel humps. Fat-tailed sheep distribution encompasses vast areas of the globe. They are the main ovine genetic resource in the Middle East and North Africa, Iran, Pakistan, Central Asian Republics, China and Mongolia, East and Southern Africa, and have important populations in agricultural export giants like Brazil or Australia. Interestingly, as to the best of our knowledge, in temperate countries, namely the European Union territory, there is only one autochthonous fat-tailed sheep breed: the Chios breed from the homonymous Greek Island near the Turkish coast. Regarding international diffusion, only two fat-tailed breeds may be classified as having acquired such preponderance: the Awassi breed original from several Middle East countries, improved in Israel and from there widespread to the entire world as a selected dairy breed and the Karakul (Astrakhan) breed form the former Soviet Union Republics of Central Asia that gained importance in the pelt production industry, curiously in fat-tailed sheep home range: Southern Africa and that nevertheless has lost the importance of the 1960s and 1970s. The wide distribution of fat-tailed sheep breeds may be explained by one particular trait: adaptability or endurance. In fact, these animals are able to thrive under extremely harsh conditions; they are able to tolerate hot weather, cope with dry environments with low pasture availability, able to walk long distances in search for pastures and drinking water, tolerate diseases and parasites, and even have gregarious and defense instincts that enable them to defend the flock from predators like jackals or foxes, similarly, to A. M. Almeida IICT–Instituto de Investigacao Cientifica Tropical & CIISA– Centro Interdisciplinar de Investigacao em Sanidade Animal, Lisbon, Portugal