[SallyintNorth]

  -where?? in December?

Precisely.  Hence why I said

less available when lambing in winter, unfortunately

and made suggestions (keeping lamb warm, giving vitamins) that may substitute for sunshine 

[Marches Farmer]

If the lamb recovers I wouldn't breed from it.

[Penninehillbilly]

although the little ones now scramble to get at mums feed, yes the lambs a very cute, 

Sounds where are the photos, we like cute photos most of all