I have a male and female cat, non-related. she 2yrs old and he's 1(roughly). both rescues. she just had a litter possible he could be father at what age do kittens have to be before introducing male to kittens?
I'm not an expert by any means. I have a male cat (non neutered) that is my rescue's child. She's very loving around him and him with her, and she had her last and final litter some time ago. My male cat despised the babies. Father or not, cats won't know if they are the dad. He would hiss and growl at the babies. Of course cats differ. When I contacted several orgs to try and adopt a kitten, they told me not to because of my male cat. Can you call your vet?
It really depends on your adult cat's personality. I spend much of my life watching ferals, and there was (he is, sadly, gone...haven't seen him since before Thanksgiving) one old tom who was very interested in and involved with all of the kittens. He would come to the feeding station and make sure that the nursing mothers and kittens ate first, and when the mothers began pushing the kittens away, I would often see him walking along the tree line with as many as seven kittens from different litters trailing him like ducklings. He is not typical, but neither is that unheard of.
I would certainly wait until the kittens are at least 8 weeks or so, 12 weeks would be better, and then monitor the introductions VERY carefully. Don't get more than a few steps away. IF he is one of those toms who does not tolerate kittens well, you need to be able to move in and remove him immediately.