Chickens stopped Laying EGGS???

Hello Evan.... thought I'd lost you in the shuffle.   Any suggestions on why these two Sussex chickens have stopped laying.  It is 7 days now and today the floor of the chicken house is covered in fine short feathers.  We keep a light in there when the generator is running and the chicken house is kept warm.  They are 19 months old. 
When we had the Leg Horns they produced wonderfully.  But they were bad at picking at each other.  Bryan thinks we might go back to the Leg Horn but get them debeaked.  The Leg Horns are also very intelligent.  When an Eagle flew over they were long gone under something.  These Sussex are not afraid of anything. 
For those of you new followers, we lost our 7 Leg Horn Chickens to a Fisher which dug a big whole under the pen and killed them all.  It took one and left the others.  That Fisher also killed our 4 beautiful Highland Lynx cats.