However, it's important to note that:
* Individual variation: Some males might mature earlier or later than others.
* Physical maturity: Even though a male German Shepherd is fertile, it doesn't mean he is fully physically mature. It's usually recommended to wait until they are at least 18 months old before breeding to ensure both the male and the female are physically and mentally prepared for the process.
If you are considering breeding your German Shepherd, consult with a veterinarian or a reputable breeder for guidance on responsible breeding practices.