Arthur Eld realized he had to find a way to reduce the amount of mutant livestock being born. The ranches and farmers at this time prayed to the Can-char, death gods, for help. Arthur realized this was increasing the power of the Outer Dark and so he instructed his scientists to find a way to stop mutant births.
They all convened at Hemphill and started their work. They took late-generation mutant horses and carefully produced a generation of threaded stock. These were then bred with others of threaded stock and soon horses, cattle, and sheep all started to produce mostly non-mutated stock. Those which were born still mutated were immediately slaughtered.
It served at the primary source of livestock for The Affiliation, with their stock being sold once every moon at the markets in Gilead. However due to the increased skirmishes with John Farson, they found it hard to keep up with increasing demand.