Anywhere Between 8 And 12-14 Wks Depending On The Strain Of Bird. Some Mature Very Early While The Bigger Jumbos Have A Lil More Distance To Cover To Get Full Size For What They Are.... So They Take A Tad Longer. They May Well Lay Eggs Before Full Size Is Acheived- Pretty Much Anytime From 6wks Old On They Can Start Producing Fertile Eggs.
the last batch I hatched I separated the biggest into one pen and put the smaller ones in another and about half of the small ones seemed to have a growth spurt I think they were finally getting something to eat they were,nt competing with the larger ones for food??