"Small numbers of pigs are easy to keep. They run free during the day and return home at night to receive their ration of garbage and substandard tubers, particularly sweet potatoes. Supplying the latter requires little extra work, for ths substandard tubers are taken from the ground in the course of the harvesting the daily ration for humans. Daily consumption records kept over a period of some months show that the ration of tubers received by the pigs approximates in weight that consumed by adult humans, i.e., a little less than three pounds per day per pig.
"If the pig herd grows large, however, the substandard tubers incidentally obtained in the course of harvesting for human needs become insufficient, and it becomes necessary to harvest especially for pigs.
"...The work involved in caring for a large pig herd can be extremely burdensome. The Tsembaga herd just prior to the pig festival of 1962-63, when it numbered 169 animals, was receiving 54 per cent of all the sweet potatoes and 82 per cent of all the manioc harvested."
--Roy A Rappaport, "Ritual Regulation of Environmental Relations Among a Ne Guinea People," Environment and Cultural Behavior: Ecological Studies in Cultural Anthropology, ed. Andrew P. Vayda.