There is no definitive answer to this question as it will depend on a number of factors, including the breed, weight, and health of the bird. However, most experts agree that Orpingtons can be butchered anywhere from 6 to 8 months of age.
When butchering an Orpington, it is important to take into account the size of the bird. A heavier bird will obviously take longer to reach maturity than a smaller one. Additionally, the health of the bird will play a role in when it is ready to be butchered. A sick or unhealthy bird may not reach its full potential weight or maturity, and as such, should not be butchered until it has recovered.
The best way to determine when your Orpington is ready to be butchered is to consult with a veterinarian or poultry expert. They will be able to take into account all of the factors mentioned above and give you a more accurate estimate.