Veterinary Medicinal Products in Manures and Soils - Problems and Solutions

Abstract

In order to improve the prospective evaluation of veterinary medicinal products (VMP), a technical guidance for laboratory tests on degradation in liquid manures and degradation and sorption in manured soils has been developed. Since the representative and reproducible sampling of manure from high-volume tanks is regarded impossible, an innovative research concept has been developed. First, excrement samples of cattle and pigs individually kept at an experimental stable were taken. These samples were thoroughly matrix characterized. Then, tap water was added to prepare reference manures of defined dry substance contents. Subsequently, the long-term degradation of VMP applied as (14)C-labeled radiotracers was investigated in those manure samples. On the basis of the degradation tests, test manures with 7-day aged VMP residues were prepared and applied in laboratory tests on degradation and sorption in manured soils. By means of this experimental approach, the impacts of aging processes during manure storage and of the manure matrix on the fate of VMP in soils can be assessed already under laboratory conditions.