I went to the food store today because I was fresh out of duck food, and they were also fresh out of the grower. So they gave me layer crumbles instead. Of course they didn't mention it and I noticed when I got home. My ducklings are only 8 weeks old and they live with their mom and dad. Should I just give them the crumbles for now and try to see when they get some more grower in? Will it be okay for them?