Yes I am guessing at day old.
I like the idea of using a normal distribution curve method in sexing like that described with leg diameter. I think that becomes more reliable as you develop a line and get the birds to be more consistent. If you do introductions of new stock where one line is considerably larger than the other this will can mess that up. I have a project like that where I am working in increasing the size and if a female has the larger body size gene she would be tossed in with the boys and vice versa, but after this breeding settles down I agree that the sexual dimorphism will be more pronounced.
This is sort of how it is with breast feather sexing at hatch, there are clear girls and clear boys and some that throw you and you need to guess.
I often use single matings in my breeding especially if I feel strongly about a pair, I still consider this a "pen" mating because in my system I track the pedigrees by the pen the birds came in, but there is only a pair in the pen if that makes sense.
Andy
I like the idea of using a normal distribution curve method in sexing like that described with leg diameter. I think that becomes more reliable as you develop a line and get the birds to be more consistent. If you do introductions of new stock where one line is considerably larger than the other this will can mess that up. I have a project like that where I am working in increasing the size and if a female has the larger body size gene she would be tossed in with the boys and vice versa, but after this breeding settles down I agree that the sexual dimorphism will be more pronounced.
This is sort of how it is with breast feather sexing at hatch, there are clear girls and clear boys and some that throw you and you need to guess.
I often use single matings in my breeding especially if I feel strongly about a pair, I still consider this a "pen" mating because in my system I track the pedigrees by the pen the birds came in, but there is only a pair in the pen if that makes sense.
Andy