Fig. 3a–d
Different habitats of the livestock herds (cattle and camels) selected for sampling. Cattle (a) and camel herds (c) grazing near Rosso (Trarza) close to the Senegal river (southern Sahel). The favorable climatic conditions permit the growth of large trees in the savanna landscape and also the cultivation of crops. In contrast, a modern dairy farm in Idini (b) is completely surrounded by desert. d Camels gathered together for sale at the highly frequented Nouakchott livestock market/slaughterhouse