Not Where's the Beef, but how old's the Beef?

Yep, I haven't posted in a few days. The neph-critter gave me one heck of a cold or something over Thanksgiving. First up from Reuters - How old is that US beef? Japan wants to know

CHICAGO (Reuters) - Stan Isaacson can look at the cattle in his sprawling Texas feedlot and estimate each animal's age fairly accurately. That skill has served him well in managing his cattle, but it will not be enough if he and other cattle producers intend to ship beef to Japan when that market reopens, perhaps as soon as late this month.

Japan will only be allowing the export of cattle 20 months of age or younger.