Chickens lay best in their first year of production after they’ve begun laying. Most chickens will slowly decline in production until they stop laying sometime in their 5th or 6th year, though this can vary a bit by breed.
Our long term goal is to have a gradient of ages among our flock, so we’ve always got some at the peak of their production, and some that are tapering off. Those that are culled will be put to good use, and all new birds rotated in will be hatchlings that are certified as pest and disease free.
We created a spreadsheet to keep track of how we plan to manage the size of the flock, and how to create and maintain this gradient of ages through culls and additions.
The numbers in bold are the number of chickens we will have of a particular age in each year. For instance, in year two (next year), we will be adding 5 new chicks and culling 3 of our existing hens which will leave us with 5 that are in their first year, 10 that are in their second year, and none that are any other age.
Based on the square footage of our coop and run, the number of nest boxes, and the amount of roost space, the ideal maximum number of chickens is about 16. Going above this number will mean more work for us in keeping it clean, and less comfortable and hygienic conditions for the chickens.
The new chicks being brought in would remain in a brooder until they are an appropriate age to introduce them to the rest of the flock, at which time the culls would take place, keeping the coop from getting too crowded.
There’s also the subject of molting and broodiness. To maximize the economic efficiency of a flock, in terms of eggs produced per pound of feed cosumed, it can make sense to cull those that are beginning to molt, or that won’t give up being broody. If we do cull based on molting or brooding, it would only be up to as many as we’ve planned to cull that year.