Hello - I have 5 Buff Orpingtons who are 1 1/2 years old. They have been neglecting their layer crumble for the last month. They aren't eager to eat, period. They will eat berries and their scratch feed, but they aren't very enthusiastic about anything, and they aren't gobbling up the layer crumble, as they have always done in the past. The whole group is doing this. I tried buying a fresh bag of crumble, but it didn't make a difference. Also, their egg production is down to an egg a day - sometimes two. Help!