Grass growth has been strange this year. It started growing rapidly in April but slowed down considerably in late April and May.
Leaving lambs on the ewes for longer is not a good option- they need to be weaned by 12 weeks so grass can be prioritised to growing lambs.
One option is to start forward creep grazing lambs from about 6 weeks of age to weaning.
Another option is to have creep lamb field gates, by this the lambs can creep ahead of the ewes on to better grass/clover swards which should be more digestible/palatable. This will help increase lamb growth, reduces stress and will also reduce concentrated creep.
Forward creeping lambs will also help to reduce the worm burned as they are grazing on clean swards reducing the risk of picking up worms.