We have 4, 9 Month old Rhode Island reds, we want more hens and trying to decide what’s best, we want more hens. Do we get babies and integrate around 2 months old? Or buy full grown and integrate after a couple weeks? We think full grown would be easiest. How far apart do we need to keep the new birds before integrating? Any help would be appreciated.
People do this different ways. What is best for one may not be best for someone else, but mostly it's doing it in a way that works for you. One big factor in any of these methods is how much room you have. In feet or meters, how big is your coop? Your run? Photos of what they look like could be useful. People that start off with only four often don't have enough room to integrate more. Integration takes more room than housing them after they are integrated.
Chicks from a standard hatchery should be disease and parasite free. To me, those are extremely safe. Chicks from a feed store are from a hatchery so are most likely safe, I'd not worry about disease or parasites from them but there is a slight possibility they could catch something from people that have chickens just walking by. Any others have the possibility of having a disease or parasites, especially if they have recently been around chickens not from their flock.
One method to counter this is quarantine. Chicken diseases and parasites can spread by chickens sharing the same ground, eating and drinking from the same bowls, by birds or insects like mosquitoes or grasshoppers, or on the wind. They can be spread on your clothing as you go back and forth between them, especially your shoes. Very few of us have the facilities for a good quarantine. We just can't isolate them that well. But if you decide to quarantine do the best you can.
Regardless of the age you get there are some generic things you can do. Housing them across wire so they can get used to each other without being able to hurt each other is helpful. When you try to merge them give them as much room as you can. You can sometimes improve the quality of what room you have by adding clutter. That means giving them things they can hide under, behind, or over. Providing widely scattered feed and water stations (hopefully out of line of sight) can help reduce conflict. Try to let them work things out at their pace instead of forcing them to share a tight space is good.
If you add mature hens that is basically it. If you add POL (Point of Lay) pullets they probably are not fully mature. They may need more separation than mature hens but will eventually blend in. If you add chicks, whether just hatched at a hatchery or older from another source it generally takes longer. Until they mature the older hens outrank them on the pecking order and are likely to peck them if the chicks invade their personal space. POL pullets can suffer the same because they are not fully mature. Most of mine seem to mature enough about the time they start to lay.
My brooder is in the coop and has wire sides. The chicks pretty much grow up with the flock. When they hit five weeks I just open the brooder door and they are integrated. A key for this to work is that I have a lot of room in the coop and outside. An 8' x 12' coop and over 3,000 square feet outside. Most backyard flocks are not going to have that kind of room. Another key is that I have the weather where they can be outside all day every day when I am integrating so they are not forced to be together in a tight space. What I do won't likely work for you but I don't know what weather you will have when you try this or how much room you have.
People integrate chicks of all ages to their flock of mature hens. There are tricks and methods we use to make this go easier. If we knew how much room you have and what they look like we may be able to come up with specific suggestions for you.
