Grazing research in the nature reserve "Oostvaardersplassen"

The vegetation to be grazed in the Oostvaardersplassen consists of Reed (Phragmites australis), Stinging Nettle (Urtica dioica), Creeping Thistle (Cirsium arvense) and limited amounts of grasses (Poa trivialis) and willows (Salix triandra, Salix alba). The year-round performance of cattle in vegetation has been studied. Food intake and diet composition were recorded with the bite count method. In grazing samples the in vitro organic matter digestibility was determined. The nutritional value of the food plants was high in summer (grasses, herbs, reed) and extremely low in the winter (twigs). The scarceness of grasses forced the animals to start eating twigs already in the end of november. The animals' body fat reserves were insufficient for a winter season started that early, so that supplementary feeding was necessary. It was concluded that the addition of sown grassland to the natural vegetation is essential for succesful year round grazing.