I bought some new babies on Thursday. I wanted to get some silkies or maybe a breed that lays those super dark eggs, but I only have one brooder. If I get chicks from somewhere else, can I put them in the brooder with the chicks I already bought?
A few days difference in age may not make too much of a difference, but silkies can can picked on by other chicks.
If there isn't that much difference in size, they should be OK... if one group is much larger than the other, the little ones will get picked on.
It depends on the breed/temperment too. I had to mix some ages in my brooder and the group which were the oldest were very sweet to the younger ones. I'd catch the pullet keeping the newly hatched warm just like a momma hen would. You could try it, but be prepared to divide them if there is too much aggresion.
I mixed my babies from 2 different places, and I realized later I should have quarantined. Nevertheless the chicks do get along very well, even the youngest cochin bantam is just one of the flock despite being less than 1/2 the size of older standard sized chicks. They even seem to take care of her. Thankfully all are healthy, but I am quarantining my newest additions, a 3 month old light brahma pullet and a 3 month old blue orpington rooster. I will integrate all the youngsters with my older chicks at the same time in a few weeks.
I wanted to add something. The big ones ARE taking care of the very tiny bantam. Yesterday I had them all outside. It was warm so they were out even when the sun was going down, huddled in a bunch with the littlest bantam in the middle of the pile. One of my australorps sits on her, looking just like a mama. She was very warm and cozy when I picked her up to return her to the brooder. In fact they were all so warm, I considered letting them sleep outside (2 1/2 - 4 week old chicks) but decided to return them to the brooder anyway. The two bantams were introduced to the larger group of babies when the older chicks were about 2 weeks old. One of the bantams was about a week old, and the littlest was only a couple of days. They have never picked on her. The older bantam is a roo and tries to dominate the bigger ones, kind of funny really because he is quite a bit smaller. There isn't any fighting whatsoever.
I would keep the groups separated for quarantine reasons. I once bought 20 chicks from a "reputable" hatchery and drove them home (they weren't shipped or anything) and lost 12 out of 20 in less than 5 days. Thank Goodness I kept them away from my 100 newly hatched chicks. We never figured out theri exact disease but one of our guesses was a disease that could also transmit to my horses. I had my farm on lockdown for 2 weeks because of this mess. I would treat any outside bird with utmost caution. If you ever lose any of the chicks and you don't know why, burn them, don't bury them for some diseases can stay in the ground for years.
I had a large variety of chicks this last batch and from a variety of places ( 3) to get the selection of chickens that I wanted. All were within three weeks of each other and I believe that is the general rule so they don't get too big. But I will say, a day old chick is significantly smaller than a three week chick, so temperment is important. The last two young chicks I added thankfully were pretty tough and pushed their ways to the feeder and waterer despite the size of the older chicks. It all worked out well though and they are now outside thankfully! I didn't quarantine and didn't have a problem, that isn't to say that something couldn't have happened and I think that more caution is always better than less! I have had some problems with chicks getting sick but I keep a really close eye on them and if any signs of illness are present I remove the sickly one immediately to quarantine. This has worked for ME, but again that's only MY experiance.
