It's not unusual for a cockerel to be rejected by older hens RJ- you will need to help him before he slips into 'hen mode' and looses his will to be in charge. Hens choose their cock for a reason, which may be they see him as attractive or perhaps a good guard or, even better, a food provider. We have never failed to integrate a youngster by using food treats. Feed the treats to the cockerel and he will call the hens to it. In time they will respond. Make sure you never get between him and the hens, otherwise he will think the hens are yours and will give up trying. Good luck.