THE USE OF PIGS IN THE COUNTRYSIDE CARE AND THEIR EFFECTS ON THE NATURAL SUCCESSION

Pigs affect the naturally succession of grassland because of their gra zing behaviour and their rooting activity. We used 4 different breeds of pigs for the investigation: German Saddle Back, Duroc, Mangalica, a nd Schwerfurter Meatbreed. The pigs were kept outdoors on grassland in the National Park ''Brandenburgische Elbtalaue'' from June until Nove mber. They were fed daily with 1 kg food containing 13 MJ metabolic en ergy and 17% crude protein with an ad libitum intake of grass and wate r. The pigs were managed extensively on an area of one ha for 5 pigs. We found that the rooting activity increased in autumn. especially fro m September onwards and the pigs were rooting the acreages up to 30%, and down to a depth of 5 to 7 cm. In the next spring after the rooting activity of the pigs different species of plants were able to germina te and to develop in the plantfree areas. After the rooting activity w e found 137 different species of plants. We found 22 species of plants in our squares before rooting activity with a share of 15 herbs and 7 species of grass in average. We established 31 species of plants afte r rooting with a proportion of 21 herbs and 10 species of grass in ave rage. In the following year after the natural succession, the vegetati on reached nearly the constitution and quantity of plants before rooti ng. We established only 13 herbs and again 10 species of grass in aver age after naturally succession. The vegetation quickly regained the co ndition before rooting, if the rooting activity fails to happen. It me ans that the favoured light-loving plants which are able to develop af ter the rooting activity of the pigs disappeared immediately after beg inning of natural succession.