Kajoda929
Songster
All chickens have an oil gland...It's how they preen. I realize this post is ten years old, but I found it searching for something else and the information is inaccurate. Gender can be identified, by those who are very good, by wings in the first few days after hatch, sometimes by feather growth(how fast/slow they feather out, but still depends), by comb size depending on breed, and around three months old, by their sex feathers. Generally the most accurate. I did have one that decided to pretend to be a pullet until he was 9.5 months old though. Literally got pin feathers overnight. I have never heard of a preen/oil gland being a gender determining factor though, because they do, in fact, all have them.They seem to be hens, if you want to be sure, look at the end of their back ( area before the tail starts and the back ends) for a round bump, it's an oil gland and only roosters have it.