4H Layer Pullets still not laying at 27 weeks!? Help!

[Altairsky]

Mine started laying at 7 months of age. She laid her first egg yesterday even if the days are getting shorter and shorter.
I only feed my chickens scratch, this recipe in particular https://www.backyardchickens.com/ar...eat-tears-a-calculator-or-deep-pockets.78655/