Cattle cycles are measured from one cyclical low in inventory numbers to the next. The physiological requirements of cattle production give cycles considerable consistency. But because of economic factors–and other factors, such as changes in tastes and technology–cycles also vary considerably. The last cycle was different in several respects. It started in 1967 and was the longest since the 16-year cycle that ended in 1928. The cyclical downturn, which began in 1975, has been the sharpest on record.