Baby guinea pigs and their father

Question
how old can they be when the baby male guinea pigs can be with their father? and also once the babies are weaned can they go back with their mothers???

Answer
The baby boars can live with dad as soon as you wean them. In fact it's better to introduce them that young as there won't be any sexual 'tension' between the boys. Dad will purr and strut around for an hour or so with the babies until he's figured out it's useless. He will not recognize them as his children, but cavy dads are great dads. They will cuddle with the babies and let the little ones crawl all over him.

Baby sows can just stay with mom, you don't need to separate them to wean them. She will do that on her own. Don't put the little brothers back with mom or they will breed her, and if there is more than one boar in with a sow they will fight. So don't let the little boys go back in the cage. If the sisters are still in there they will mate with the sisters as well.

A sow typically weans her babies at around 6 weeks by refusing to let them nurse, so there's no need to remove the baby sows unless you are rehoming them.

Hope this helps.