Mixing breeds

[cmelancon89]

Hey everyone. I'm still pretty new to this. I have a small flock of mixed breed chickens. I'm wanting to get some pure bred (Sussex to be exact). If I do this would I be able to tell if I have pure bred Sussex chicks or would they all be considered mixes? I'm thinking I'd get rid of my current roosters and just have a Sussex rooster but I'd still have the mix breed hens.

 

[I Love Layers]

I'm not sure you could tell at hatch but maybe later in life by looking at comb, feet, egg color, color of the bird just to name a few. If you had only a Sussex rooster like you said you might do you would know what chicks were there's if you don't have any other chicken that lays the same color of eggs.
Another thing to do is to build an area where your Sussex rooster and hens can be together with no other chickens to ensure that you are getting purebred sussex chicks.
Good luck!