Work package IV will investigate the effect of different feeding variants on the performance, health, and behavior of animals on commercial farms. There will be two rounds, one for laying hens and one for their brothers (broilers). In the first round, farm-specific feed mixtures with a focus on reduced nutrient density (especially crude protein and methionine) will be used. The test period for differentiated feeding in the laying hen groups will start at the peak laying period (no later than week 32) and end when the animals are removed from the house (week 68). For the laying hens, trial data will be collected during three farm visits (week 30/35/68), and for the fattening groups on two dates (week 8/16). In addition to the on-site animal assessments according to M-Tool (including weight determination), the following parameters will be determined over the trial period: 

• Output and selection feed
  (Wender, XS, XZ, AS, CA, P, Na, feed structure)
• Entries through feces in the soil
  (DM, N, P)
• Fecal quality
  (DM, N, P, flotation, grading)
• Egg quality
  (Shell and yolk color; egg, shell, and yolk weight; break resistance; shell thickness, meat & blood spots)
• Carcass examinations
  (Changes in skin and joints; weight, changes and fat content of the liver, stomach filling and weight; kidney weight and changes; length of the small intestine)
• Meat quality
  (Meat color, weight of cuts, shear force of breast muscle)
• Breaking strength Tibotarsus
  (Stiffness [N/mm]; Maximum load [N]; Postyield displacement [mm]; Work-to-fracture [Nmm])
• Feathers
  (length, thickness, mass, protein content)
• Utilization of the outrun
  (Evaluation of photos of the vegetation)