Die Bodenkultur - Journal for Land Management, Food and Environment
M. Sager, G. Reichel, M. Grüner and H. Würzner:
Mercury contents of animal feedstuffs in Austria
For reasons of health and sanitary control, 327 samples of various feedstuffs utilized in Austria, were investigated over a period from January to October 1996 for their Hg contents. As a method, combustion in oxygen, amalgamation, and atomic absorption measurement was used within a closed system. As the only manipulation was weighing the sample, low blanks of the entire procedure and sufficient sensitivity enabled us to achieve detection limits of 0,01 ng absolute. The validity was checked by international standard reference materials, and the precision of the method within the range 1-10 µg /kg was ± 7.6%.
Most samples contained 0,2-10 µg/kg Hg. In comparison with data from crops and vegetables from the Netherlands, distributed among various labs within the international plant exchange program to improve the quality of trace analytical results, the Hg-contents utilized for animal farming in Austria was at a significantly lower level. Generally; feed for pigs was at a higher Hg-level than feed for cattle and horses, for poultry it was intermediate. Correlation and factor analysis between Hg contents and the components of the feed mixture clearly revealed processed fish as a significant source for Hg, whereas the total contents of Cu, Zn, and P was of no influence. This is in accordance with earlier studies of humans and animals of high fish consumption, which has been outlined within a brief review about occurrence and metabolic pathways of Hg in animals.
Key words: mercury, trace analysis, feed, nutritional level, processed fish.