When you solve the problem that is associated with the attention, the attention disappears. This means:
For the Tag (I)FE: as soon as the cow starts eating again.
For the Tag (I)FER(P): as soon as the cow starts eating, ruminating or showing other active behavior again.
For the Tag Leg: as soon as the cow starts standing again.
Also, when you select the cow and click on Action > Seen, the urgent attention disappears.