Difference

[chicken24]

Dominant white colored chickens will have pale yellow down as chicks. Both breeds are identical until about 2 weeks old. Then the size difference becomes quite dramatic. White Rocks take about 16 weeks to reach adult size. The Cornish X will be that big in just 6 to 8 weeks.

What does it mean by dominant

 

[junebuggena]

There are two types of white in chickens, one is dominant, one is recessive. Some breeds, like White Rocks, White Leghorns, and Cornish X are dominant white. Other breeds, like Cochins and White Jersey Giants are recessive white.
Chicks with dominant white genes will be pale yellow.
Chicks with recessive white are grey or even black and then turn white when their feathers grow in.