A Nyangatom boy catches blood from the artery of a cow in a gourd. The cow is bled by firing an arrow with a very short head into the artery of the cow. Several pints of blood will be collected which will then be mixed with milk and drunk by the Nyangatom. The Nyangatom or Bume are a Nilotic tribe of semi-nomadic pastoralists who live along the banks of the Omo River in south-western Ethiopia.