When is it time to retire the breeders? I would retire when the female has her 5th or 6th litter. It's my personal choice to go no later than the 6th litter, no matter her age.
From birth to weaned how long? 3 1/2 - 4 weeks.
Birth to breeding age males and females how long? Males, for me it depends on the size of the male. Many females just wont let a small male mate them. So at least the same size as my females, or just a tad smaller. Around 3 months of age for mine.

Females, at least 250 grams, although i still think that is small, and prefer my girls to be over or close to 300. No younger than 5 months of age.