size of eggs.

[yogi]

I have 6 red sex-links and 6 White rocks. They are all 22 weeks old and started laying at 18 1/2 weeks. The White Rock eggs are much smaller than the sex-links even though they are much larger birds. . Will the Rock eggs get bigger as they grow older and is it because the Rocks are slower maturing birds?

 

[Ridgerunner]

The Rock eggs will get bigger as they mature. The sex link eggs probably will too.

There are two different kinds of sex links sold by hatcheries. One kind is made by crossing regular hatchery chickens. These should be about the same size as your Rocks and lay eggs about the the same size.

It sounds like you got the other kind. These are the commercial egg layers. They are smaller in size. This means they are more efficient in converting feed to eggs since they don't need to use as much energy maintaining the larger bodies. These chickens have been developed to lay a lot of large eggs early.

I don't know that the Rocks eggs are smaller because they are slower to mature. The eggs are smaller because the Rocks have not been bred to lay large eggs early.