As I understand it, the ewes should be done beofre they lamb. This is the ewes annual booster and all they should need.
New lambs would be done at 4 weeks and then again at 8 weeks.
Last years lambs would be done when the ewes are done pre lambing.
If you are not sure if the ewes/last years lambs have been covered properly, do them with this years lambs (ie two jabs 4 weeks apart).
I think
