Oromo society is modelled on the Gada system. This system represents one of the most complex systems of social organization ever devised by humans. Men are divided into age-groups according to two criteria, their physical age and the Luba generation to which they belong. The Luba is determined by the generation position of the father, not by the age of the son. The complete cycle is eighty years, divided into two periods of forty years each, counting 10 grades or Gadas, which last about 8 years each.

Throughout their lives, males pass through these grades, each of them having certain social activities required of their members, such as ceremonies and ritual sacrifices.

The Borana people live in southeast Ethiopia, just north of Kenya. They are semi-nomadic and dedicated primarily to herding. Their zebu cattle (Bos Indicus) are known for their robustness and quality.

The Borana are divided into two groups, Gona and Sabbo, that include all the calns. They are polygamous and all marriages are contracted between both groups (the three Gona clans and the fourteen Sabbo clans). Linage is patrilineal and their social organization, based on the Gada system, an example of pyramidal democracy.

The encampments are set up around a vital water point. The singing wells (hella) are of great importance. The Abba Hella regulates the access of the herds to the wells, as well as establishing the ‘‘human chain pumps’’ to extract the deep water in stages via levels or terraces. Two or three men at each level draw the water up to the upper level using rebber or plastic containers or lorry tyres (they used to be made of giraffe skin), to the rhythm set by their songs.

Within the Borana, certain clans dedicate themselves to the extraction of salt from the lakes formed by volcanic craters. The most important of these lakes is Chew Bet, near Yabello. Transported by mule, the salt ascends the steep sides of the crater and covers the needs of humans as well as those of the valuable livestock.