For Harlander-Matauscheck (2006) feathers in “the speed of feed passage have a similar than insoluble fiber. The dietary effect of increasing feathers may be a crucial factors in the development of feather pecking and the related damages to the feather cover in laying hens. Sunflower appears to be the ideal raw materials, lowering the energy level, increasing the volume to ingest and having a high percentage of coarse fibre or acid detergent lignin. Maximum limit to use are unknown but, as we know it is likely to be over 30%. Countries using sunflower have generally few problem of feather pecking and mortality.