This is NOT a genetic thing an that there is not a gene for a cockerel that will be predestined to holding his wing up tight and another gene that will predestine him to hold it low. It is a vigor thing. Compared to the genome of the entire chicken species the gene pool of an individual breed of chickens is very narrow. This limiting of the gene pool leads to a genetic depression that can result in weak birds. Holding the wings low is an early sign of this genetic depression. The first priority in selecting breeding stock when working with standard bred fowl is vigor. That is especially true in rare breeds. If that is not the focus then each generation your flock gets less thrifty, less active, more susceptible to illnesses, etc. When left unchecked you see a drop in fertility, low body weight, increased mortality in the flock, reduced production, etc. The weak wings is very common in the cockerels but almost never see on a hen. If you ever see a hen with weak wings turn her out to the garden right then because she will be of no value in a breeding program. With the cockerels don't use a cockerel with weak wings if you have any other options. If he were the only one I had I would use him but I would not use any of his sons unless they showed good vigor. Yes a lot of the Rees line birds have lots of weak wings. Any line that you have you will need to grow out as many as you have room for so that you have enough selection to get breeding stock with out any weaknesses to move foreword with. Every flock requires culling. You can't stay at the Status Quo. If you aren't moving foreword with your flock is will be sliding backwards.
