Advice needed for merging little ones with the older guys

[rhea]

Next week, I will be bringing home 4 RIR's, 4 Bluff Orpingtons & 8 Silver Lace Wyandottes, all 1 day old. Will have them all in the house till weather is warm enough for them to spend atleast the days outdoor. They will be joining my group of an Americana rooster & two hens, 1 year old and two 4 years Bluff Orpington hens. For housing, I have a good-sized main house with six nesting boxes and 2 eight foot roosts; a tractor with an enclosed yard that is in a fenced garden (approx.1/4 acre) where the flock spends their days. What age is best? Will the difference in numbers be a problem? Will my rooster do well with that many hens? Do I have enough space? How soon can I vary the little ones' diet? Any and all advice will be much appreciated.
Thanks,
Rhea

 

[Judy]

Most here feel that the new ones need to be the same size as the adult birds before you try mixing them. Most also put them near each other for a few weeks, where they can see each other but not get at each other, before the mixing. Some mix them in at night when they are on the roost, and some do it while they are free ranging. No one can tell you how they will react, as it varies. For sure there will be some pecking and squabbles as they rearrange their pecking order. Hopefully it will not get bloody so you won't have to intervene.

I start treats at a few weeks but keep the quantity small. I don't remember seeing any clear guideline about this here. Hopefully I'm not hurting them....