many many thanks for clearing that up for me..im always up for a bit of learning 
but now i have a question for you...can i make some sex link chinks out of any of these chickens?
i have
an orpington roo - he's a cuckoo colour x split 'parelgrijs' (i think that means hes grey from colour with barring)
a couple of roos with mostly red colouring but are not RIR (their mum was a rir, dad was an ee)
cuckoo marans roos
australorp roos
brahma partridge roo
barred rock roo
barred rock hens
orpington hens (black)
brahma hens (patridge ones and black ones)
RIR hen
lots of production red hens
marans hens (cuckoo and black copper)
an white chicken but unsure what she is
im thinking the best bet is the red roos with BR hens? or try and get hold of a rir roo?
Assuming these are all purebreds, your Partridge Brahma roo and your Australorp roo are the only roos that would reliably produce sex-link chicks. Your RIR x EE roos possibly could make sex-links, but since EEs are mutts there's no way to know for sure other than just trying it and seeing what you get. You can cross your Aussie or Brahma roo with your Barred Rock and Cuckoo Maran hens and make black sex-links. 
super! thank you for letting me know...i shall give it a try 
*Rooster Obsessed!*
*Rooster Obsessed!*













