High feed intake in layers

hullo every one.now a days I am facing a problem.i have a flock of 15000 layer.aging 34 wks.its feed intake is 120gms per bird per day.all the birds finish feed with in 15 to 20 minutes.my feed formulation is as under corn=455kgs=rice polishings=140kgs,feathermeal=40kgs,corn meal=50kgs,gluten60%=11kgs,gowar meal=30kgs,soya bean meal=45kgs,canula oil=07liters,fish meal with 44% protein=40kgs,canula meal=75kgs,limestone=82kgs,dcp=10kgs,gluten30%=07kgs, lysine hcl=1500gms,methionine dlm=1400gms,choline choloride=1000gms,toxinbinder=500gms,zinc bacitracin=300gms,natuzyme=500gms,salt=1500gms,sodium bicarbonate=700gms,vitamins and minerals pre mix as recommended by the company.kindly guide me.waiting for your suggestions thanks.