Integrating new chickens

[Cockstrongorcocksure]

So I have a flock of 9 pullets, all about 11 weeks old. I am getting 3 bantam full grown hens, 1 silkie and 2 cochins. So they should be the same size, how long should I wait before fully integrating?

 

[DobieLover]

So I have a flock of 9 pullets, all about 11 weeks old. I am getting 3 bantam full grown hens, 1 silkie and 2 cochins. So they should be the same size, how long should I wait before fully integrating?

Months.
You need to keep an eye on the Silkie. Being the lone bird with abnormal feathers in a flock of normally feathered birds may lead to problems if they are short on space and enrichment in that space.
Size does not have much of an impact on the acceptance of birds. You need to keep the two groups in view of one another but separated by fencing or something for at least 7 to 10 days before allowing them to intermingle under supervision. They won't form a hierarchized flock until all of them start laying.

 

[aart]

Consider biological/medical quarantine:
BYC Medical Quarantine Article

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/

 

[Ridgerunner]

So I have a flock of 9 pullets, all about 11 weeks old. I am getting 3 bantam full grown hens, 1 silkie and 2 cochins. So they should be the same size, how long should I wait before fully integrating?

What do you mean by fully integrated? To me, it means that no one is trying to hurt the other. To some people it means they are sleeping close together, eating and drinking from the same dishes at the same time, and just one happy flock being closely side by side.

Do not fall into the trap of believing size means anything as far as dominance. It doesn't. There are plenty of cases where bantams dominate full sized fowl, even when grown. What I find to be important is maturity. A more mature chicken will dominate a less mature chicken until they are all at the same level of maturity. With my flock that usually means that the pullets are able to fully join mature hen society about the time they start laying. Until then I have two sub-flocks. They don't hurt each other but the young ones avoid the older ones, during the day and when sleeping at night.

What do your facilities look like? How big are your coops in feet or meters? How big are your runs in feet or meters? How do they tie together? Photos can be helpful. Aart gives excellent generic advice but how you can apply that depends a lot on what you are working with. I cannot give you any specific advice that is better than Aart's without knowing your specifics.

People do this all of the time. Sometimes it is pretty easy, sometimes it can be really stressful. The more we know about your specifics the more likely we can help.

Good luck!