Recently discovered that Sussex hens have large eggs, so decided to have a run of sussex hens and roos. Used to have barred rocks but their eggs used to be all sizes. Now i am looking for sussex chicks, hens and roos. please feel free to email me if you are selling any of the mentioned and i will be keen to buy them off you. just messgae me availability and photos and i will be in touch.
I've had Sussex and Barred Rocks for decades without noticing any difference in the size of their eggs. Young pullets do lay small eggs, and old girls large ones. Are you sure this isn't what was happening?
Egg size and consistency is very much inherited so unless you can get birds which have been selected over generations for egg traits like numbers, shapes and size then you may well find just as much variation within Sussex as in Barred Rocks if you get stock from several lines that have not been selected this way.
When you breed you should always choose eggs that come from the hens that are the best in terms of numbers, shell quality and regular size- plus breed them to a rooster whose mother was also the best you can find.
Light Sussex used to be among some of the best breeds for eggs, before the hybrids came along, but today they are mostly bred for their looks rather than their eggs!
Yes, as Mudlerk has indicated a pullet laying her first few eggs they will be reasonable small but each egg should be just a little larger than the last as the bird matures. In her second season of lay her eggs will not go back to being small like at the start of her first egg laying season but will start off being of average size, possibly gaining a bit as the season advances and she doesn't lay quite as consistently day after day.