However, it's important to note that:
* Individual variation exists: Some males may reach maturity earlier or later than this range.
* Full sexual maturity: While they may be fertile at 4-6 weeks, they may not reach full sexual maturity until around 3 months old. This means they might not be fully developed physically and may have less sperm production.
Therefore, it's best to wait until a male guinea pig is at least 3 months old before breeding him. This ensures he's physically and developmentally ready for the demands of breeding.