Introducing new chicks/chickens to existing flock

[Deanamw30]

This is our 2nd year with raising chickens. We have 15 hens that are a year old and we will be adding 10 more once they are old enough. My question is what is the best way to introduce the new chicks to the current flock and how old should they be when we do?
Thanks!!

 

[Pretty Birds]

what is the best way to introduce the new chicks to the current flock

You could divide the coop with some wire so the so the two groups of chickens can see each other. I would do this for 1-2 weeks and then take the divide down. Some minor pecking can be expected, but you should still monitor the flock and make sure the original chickens are not attacking the new chickens.

 

[Ridgerunner]

To me it is not a question of how old they should be, but more of what do you have to work with, especially room, and what are your techniques. Many of us start to introduce them as soon as they are safely off the heat. My brooder is in the coop so I start that process as soon a they come from the incubator or post office. Some wait until they are practically grown to introduce them.

You gave us the numbers, thanks, that helps and is encouraging. We don't know where you are located or what time of year you plan to do this so we don't know the probable weather, but most chicks are able to handle the weather most places by 5 weeks. How many coops and runs do you have, how are they fitted together (photos can help), and how big are they in feet or meters? Basically, what do you have to work with?

I have a fairly large coop, a lot of area outside (in the range of 3,000 square feet), and weather that the adults can be outside all day every day except when they are in the coop laying eggs or sleeping. I put chicks in that wire brooder straight from the incubator or the post office so the chicks pretty much grow up with the flock. My broods are typically in the range of 20 chicks but I think I've done as few as 7 this way. My adult flock consists of a mature rooster and some mature hens. I have several widely separated feeding and watering stations. All these things factor in. I typically open the brooder door when they are 5 weeks old and walk away. That's my integration.

If your conditions are different this might not work that well for you, could be a disaster. Others have different techniques for integrating young chicks and older chickens. @aart has a copy and paste generic description of common techniques. Since we don't know what you have generic is the best we can do.

My definition of a successful integration is that no one gets hurt. That's it. All that cum-ba-lah stuff of them acting as one cuddly flock, eating and sleeping together can and will happen once they all mature. With my pullets that's typically within a few weeks of them starting to lay eggs. Until then they form sub-flocks and pretty much avoid each other. I'm pleased as punch because in one is getting hurt.

 

[aart]

I integrate chicks early, but spent some effort to set up coop to do so:
https://www.backyardchickens.com/articles/integrating-new-birds-at-4-weeks-old.72603/

And also follow these guidelines for......
Integration Basics:
It's all about territory and resources(space/food/water).
Existing birds will almost always attack new ones to defend their resources.
Understanding chicken behaviors is essential to integrating new birds into your flock.

Confine new birds within sight but physically segregated from older/existing birds for several weeks, so they can see and get used to each other but not physically interact.

In adjacent runs, spread scratch grains along the dividing mesh, best if mesh is just big enough for birds to stick their head thru, so they get used to eating together.

The more space, the better. Birds will peck to establish dominance, the pecked bird needs space to get away. As long as there's no copious blood drawn and/or new bird is not trapped/pinned down and beaten unmercilessly, let them work it out. Every time you interfere or remove new birds, they'll have to start the pecking order thing all over again.

Multiple feed/water stations. Dominance issues are most often carried out over sustenance, more stations lessens the frequency of that issue.

Places for the new birds to hide 'out of line of sight'(but not a dead end trap) and/or up and away from any bully birds. Roosts, pallets or boards leaned up against walls or up on concrete blocks, old chairs tables, branches, logs, stumps out in the run can really help. Lots of diversion and places to 'hide' instead of bare wide open run.
Good ideas for hiding places:
https://www.backyardchickens.com/threads/a-cluttered-run.1323792/