my Dad raised chickens when I was a kid so I know a little but I don't know much about crossbreeding.... I just started my own backyard flock - they are about 6 weeks old right now and I have 3 Araucana easter egg hens, 3 barred rock hens, 7 RIR hens and a RIR rooster - and a 'freebie' I think is a bantam cochin rooster - it's feather footed and black but I'm not completely sure about it yet since it was a 'bonus' in my order. I'm debating whether to keep or find a new home for the freebie... especially if it is a rooster... my question though is about my RIR rooster - I have a separate pen that I can house him in once the hens start to lay eggs... but will he be happier with 'his hens'? and I've read the RIR rooster with barred rock hens will give sex-link chicks? I need to do more research obviously - I'm also applying to Veterinary school so I do know basic genetics but not much about specific chicken breed genetics. what will the RIR rooster produce with easter egg hens?? what about if the freebie is a rooster - can he breed with my other hens and then what will I get?!? I ordered online from a hatchery to start off so I would know what breeds I have to start learning... If I end up with sex links and then those breed... THEN what will I get - this is my concern - If I just let them free range and I let some eggs hatch, I'm wondering if I'm going to end up with some weird mutt chickens or what LOL This is why I have the separate pen set up for my RIR rooster... so I could pen him up and only let him have access to my RIR hens to start so I can keep track of what I have!! any info and advice is much appreciated!
Let your poor rooster be with the hens all the time. He will be miserable by himself. He will breed all the hens, look after them, live a normal flock life. If and when you want to hatch eggs, you can then separate him and the red hens if you wish and only incubate their eggs. Or, you could leave him with the flock and incubate the brown eggs, those would give you pure red chicks and black sex link chicks. None of the breeds you listed tends to reliably go broody from hatchery stock, so if you want chicks you'll probably have to incubate the eggs yourself, making it very easy to choose which eggs you hatch. But, it's fine to let breeds mix and hatch mixed breed chicks. This is what I do and I get some run-of-the-mill looking birds, then some really pretty surprises like this girl. Best I can figure her father is a black sex link rooster and momma is an Easter egger. Wish I knew for sure!