- A broiler feeding trial with 4 treatments with decreasing dietary protein levels while maintaining amino acid balance over four feeding phases was conducted.
- Reduction of nitrogen intake by 8 % (treatment 3) did not affect weight gain and feed conversion ratio while nitrogen excretion and litter weight were reduced by 19 % and 21 %, respectively. Percentage of chicken foot pads with no lesions (score 0) almost doubled.
- Reduction of nitrogen intake by 13 % (treatment 4) reduced nitrogen excretion and litter weight even by 26 % and 27 %, respectively. Percentage of chicken foot pads with no lesions were almost tripled compared to standard. However, final body weight and feed conversion impaired by 2.6 % and 1.8 %.
- Carcass evaluation provided indifferent data for male and female birds but indicated that meat deposition might have slightly suffered with protein reduction.
- Reduction of dietary protein (treatments 3 & 4) allowed for meeting legally requested target values for nitrogen excretion.
- Economic calculations confirmed that at least treatment 3 was competitive to the standard feeds but offered advantages concerning environmental and chicken welfare aspects.