Combining new chickens with existing flock

[ChickenMan77]

We have 4 hens which are 1 year old. One of our EE's and our Buff Orpington are at the bottom of the pecking order. Our Plymouth Barred Rock is at the top and the other EE is right behind her. Well..at least this is what I think based on what I have observed. I have 5 new chicks which are 7 weeks old (two Silver Laced Wyandottes, two Rhode Island Reds and one Black Australorp, which might be a rooster judging by the advanced comb growth). I combined the two groups almost two weeks ago.
The first week I let them all free range around my yard and the older ones mostly ignored the younger ones unless they got too close to them and then there was a short chase. I recently planted grass seed so for the past week they have all been in the coop and run together. After a day of squawking and pecking I divided the run in half and gave the chicks the coop with food and water and a small portion of the run just below the coop, the older hens have the largest part of the run with a roost and some temporary nest boxes, food and water. I have covered the run with plywood for now to provide shelter.
Both sets are happy being separated but the younger ones won't come down from the coop into their run, though it is blocked from the hens with chicken wire, because they feel safer totally secluded from the hens I would assume, and the hens hate the temporary nest boxes I have given them in their run. Last night I took the divider out of the run and combined the groups again and things went a bit better with only the Barred Rock and one of the EE's chasing the little ones when they got close to the food. The little ones are still very scared of the older ones and will only run away. I don't think any sort of pecking order is being established due to the size difference in the two groups.
OK here are the questions; Have I combined the chicks with the hens too soon? Are the chicks too small in size to be with the hens since they don't have a mother to look after them? Should I try to continue keeping them separated or should I just let them go at it? I also have the chicks on organic grower feed but the hens on layer pellets. The chicks don't seem to be too interested in the layer pellets but the hens do enjoy the grower feed. I don't want the chicks to get too much calcium so I am trying to keep them away from the grower but every day they are taller and closer to reaching the layer feed. How much of an issue is this? I know the chicks shouldn't be on layer till they are laying so how do I manage the feeding of the groups if not keeping them separated? Does anyone have some good experience with this?

I have also observed that though the two groups aren't separated any longer, the older hens have chosen to sleep outside on the roost in the run rather than going into the coop. The chicks sleep in the coop with a heat lamp since it is still early spring in Colorado and it gets down to freezing at night. Are the hens choosing to stay outside because of the heat lamp or because of the chicks? When not restricted from the coop the hens do still go in there to lay eggs and swipe them selves some grower feed.

 

[QualityPolish]

Okay well, I would have suggested intermingling them into the hens during the night since everyone is a little groggy then and in the morning the only thing on their mind is food. I would have combined the hens and chicks once the chicks reach the size even with the hens just so they can hold their own. Because they are smaller and weaker than the hens I personally separate them because of injury reasons etc. just to be safe. As for layer feed etc. I would keep the chicks on the starter until they are hen size and have access to grit or small rocks to help break down the pellets. Starter is made especially for chicks and in small powder form so they don't have to have small rocks to help break down the powder and little tiny pellets. Since they are 7 weeks old you could start switching them over to different feed as long as they have access to grit but at this age I would say if they want it let them have it although I don't feed layer pellets to our chickens, just normal chicken scratch that has a mixture of corn and seeds so I wasn't worried about the calcium. I'm sorry so say but I can't give a straight answer to that one :/ Since they aren't laying they don't need that much calcium but I don't know how you could separate them. As for the hens hating the chicks or the heat lamp I would say chicks, just because we have a heat lamp in our coop and it doesn't seem to effect them so maybe they just don't feel like dealing with the chicks lol.

Sorry for not giving you really any straight answers but I hoped it helped somewhat.

 

[OreoPlymothRock]

just wait until the chicks are about the same size and then you can mix them

 

[ChickenMan77]

Ouch! Got home tonight and one of the Reds was pecked under one of her wings, missing feathers and blood. I have divided the groups again, creating a better situation this time around for the laying hens to lay in a better nesting box. We'll try this again in a few weeks.