Chick grit in brooder - when to add?

[Lumikko]

Hello all. Newbie question but when do you recommend adding chick grit to the brooder? Thank you.

 

[Ol Grey Mare]

I introduce plugs of sod to be picked through by the end of the first week, they take grit from that and I sprinkle some in their soaked feed as well....appropriate grit at all stages develops a strong, healthy gizzard for pater, regardless of if you are only offering chick crumbles at that point