Silver Laced Wyandotte, 9 months old, hasn't started laying yet.. why?

[Agincajun]

2x oldhenlikesdogs....When I did the switch from Chick Starter to Layer at 18wk no one laid until they were 8 - 10 months! I have had Orpingtons, Wyandottes, EEs & RIRs. Then I read about Flock Raiser, it's made a difference! Plus I ferment their feed....

Someone gave me 5 Blue Wyandottes that were 6 months & not laying, they were on layer. I put them on FR (Oyster Shell on the side) within a couple of months they were laying, figured it would take some time due to the move & change. They even warmed up to me but then it came time for them to go back to their owner.

I got 4 BOs at 8wks put them on FF/FR....The 1st laid @ 25wks, 2nd @ 28wks, 3rd @ 29wks & 4th @ 30wks. So far all are giving me eggs every day

What is FF and FR?