Legehennen in einem mobilen Stallsystem - Flächenmanagement und resultierende Stickstoffgehalte im Auslauf -

Summary

In the last years free range poultry was often criticised for its negative impacts on environment. As the animals do not use the run equally, a big part of the excreted nutrients are accumulated in the area close to the poultry house. This can lead to an increased rate of nutrient loss especially nitrogen by leaching.
Within this study the use of a mobile housing system for 1.000 layers on an organic farm in North Hessia with a mean of 700 mm precipitation per year and an average of 8,9°C (soil texture: loam in the first, silt loam in the second year) was observed for two years. A documentation and optimization of the management and regular investigations into the contents of mineral nitrogen in all parts of the outdoor run were carried out. The aim of the study was to survey, if a well-balanced distribution of nutrients can be reached by moving the house within the free-range and which management is necessary for that.
The results showed a better distribution of mineral nitrogen in the second year, when the house was moved in winter time every six weeks, while the contents were slightly less well-balanced, when it stayed at one position for three months in the first winter . In both years the highest amounts of mineral nitrogen in any part of the hen run with 37 and 24 mg / kg DM were much lower than the contents of up to 160 mg / kg DM close to stationary houses examined in other studies. The results of this study show that a well-balanced distribution of nutrients in free-ranges for poultry can be reached by using mobile housing systems combined with the right management.