4m x 3m Omlet pen, cube, new auto door still boxed and coop light

[Chickaboo]

My two girls have been on a different diet (other than layers pelletts) for last 6mths recommened by vet, as Phoebe was having a soft egg problem. She has started laying again and was thinking of gradually re-introducing the pelletts. I have an almost full sack in the garage that will be 6mths old - its dry, will this be ok to use? I know they say use within 3mths, is there any particular reason?

[Egluntyne]

I believe it is that the vitamin content begins to deteriorate.