the following link is about the measurement that US government took when there was a risk regarding BSE in imported beef.

here’s the summary:
The Board is asked to note the measures that are in place prevent imported beef from cattle
aged over 30 months at slaughter (OTM beef) from being sold for human consumption.
The Agency has recently required enforcement activity to be stepped up. High compliance
levels have been found and the trade’s awareness of the ban and its importance have been
reawakened.

but maybe.. FTA prevents to do this kind of ban? just like UPS sued canadian postal service?