When to put chicks with rooster

[MarketGardener]

I wonder the same I have my rooster I want down at my land where I meat birds for security as we have minx and foxes and apparently he will keep em away and alert ladies and me when around
but I worry about him always having a new flock when I cull the young ones at 14 weeks to 26 on some breed and then what age can I add them back