The epidemic in cattle in Britain reached incredible proportions; by 1993 more than 1,000 cases per week were being reported. More than 160,000 infected cows have now been identified, involving more than 50% of the dairy herds in the UK. Protein supplements containing sheep and cattle offal were banned in the UK in 1988, but it was not until 1991-1992 that the ban was strictly enforced. Given the long incubation of BSE, the epidemic curve (number of new cases reported per week) didn't start downward until late 1993. It is now down to about 250 cases per week.