Welcome!
I have Derbyshire Gritstones, a hill breed, who are quite well covered at the minute and also due to lamb the end of March.
They have just started hay and have a crystalyx energy bucket which will continue until after lambing.
This year I haven't scanned (normally do so I know what to feed) so I plan on condition scoring them regularly but will probably feed a 'cover all bases' of about 250-300g in the last 3 weeks of pregnancy. If any seem lean based on the condition scores they may get extra, earlier and be split up from the others.
I'd like to say they do well on minimal feeding as gritstones typically only have one, sometimes two lambs but last yea we have 30% triplets which required a lot of tlc hence the regular condition scoring this time.
Hope that helps