Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2004
Publication Date: 7/1/2004
Citation: Wachendorf, M., Sanderson, M.A., Baade, J., Taube, F. 2004. A sward-based method to estimate herbage selection of grazing dairy cows [abstract]. Pasture Ecology Abstracts. p. 16. Interpretive Summary: An interpretive summary is not required.
Technical Abstract: Diet selection of grazing animals is influenced by the sward composition and the vertical sward structure. Grazing studies were established in Germany (Kiel, State Schleswig-Holstein; GER) and in the US (State College, Pennsylvania; US) to determine if selective grazing behaviour affects the sward structure among different sward layers. Pastures were a white clover-grass mixture with Taraxacum officinalis (GER) and a mixture of nine temperate forage species (including grass, white clover and forage chicory) in US. In both experiments the vertical structure was measured before and after grazing with special clipboards dividing the samples into layers of 5 cm and a succeeding separation in different plant groups. Forage samples of the different layers were analysed for nutritive value via calibrated near infrared reflectance spectroscopy. The measurements were conducted in 3 (GER) and 4 (US) grazing periods during the grazing season allowing the calculation of herbage disappearance as an indicator for diet selection as well as the CP content (GER) and IVTD (US) of the disappeared herbage as an indicator for the consumed quality of herbage. In German pastures, cows selected Taraxacum and white clover to grasses, and in US pastures, cows preferred legume to grass and young chicory leafs to bolted chicory stems as well. In both experiments, this resulted in an increased forage quality of the herbage consumed. In both grazing studies, herbage disappearance and CP/IVTD of disappeared herbage indicated that, by using a sward based method, quantity and quality of consumed forage can be estimated in its dynamic within the grazing period.