The effect of allocation frequency in rotational grazing systems on the fatty acid profile in milk fat of dairy cows
Vlaeminck, B. ; Abrahamse, P.A. ; Fievez, V. ; Lourenco, M. ; Dijkstra, J. ; Tamminga, S. - \ 2010
In: 23th General Meeting of the European Grassland Federation, Kiel, Germany, 29 August - 02 September, 2010. - Duderstadt : Mecke Druck und Verlag - p. 102 - 102.
Four Holstein cows were used to evaluate the effect of allocating cows every 4 day (d) to a new 0.5-ha plot of Lolium perenne L. on the profile of fatty acids (FA) in milk. The experiment was run during 2 rotations with 2 measuring periods of 4 d each. During the 4 d period, the proportion (g per 100 g FA) of 18:3n-3 and total FA content (mg per g DM) of grass decreased linearly. Similarly, milk FA composition was largely affected by day within the 4 d period. Proportions of t11-18:1 in milk fat increased on d 2 (4.52 g per 100 g FA) and decreased thereafter (3.77 g per 100 g FA on d 4). Proportions of c9t11-18:2 (2.36 and 1.83 g per 100 g FA), t11c15-18:2 (0.81 and 0.63 g per 100 g FA) and 18:3n-3 (0.92 and 0.88 g per 100 g FA) in milk followed the same pattern. Results from this study suggest short term variation in pasture quality during the 4 d affected milk FA composition, with a greater effect on biohydrogenation intermediates in milk fat compared with its major precursor, 18:3n-3.
Producing milk from grazing to reconcile economic and environmental performances
Peyraud, J.L. ; Pol, A. van den; Dillon, P. ; Delaby, L. - \ 2010
In: 23th General Meeting of the European Grassland Federation, Kiel, Germany, 29 august - 02 September, 2010. - Zürich, Switzerland : European Grassland Federation EGF - ISBN 9783869440200 - p. 163 - 164.
Several reports, directives, regulations and initiatives challenge high-input dairy systems at the environmental level. At the same time the dairy sector has to adapt to a greater volatility of prices and to the projected increase in energy and fertiliser prices. In this new context, it should be considered whether the model of development based on intensification, often in connection with the reduction in the use of grazing, is always well adapted. Dairy systems that maximise grass utilisation appear to be highly competitive and the various roles of grassland in providing regulating and supporting services are now widely recognized. Thus grassland should form the basis of more sustainable dairy systems in the future, provided technical innovations are produced to improve the efficiency of grassland-based dairy systems. Innovations in forage production, innovations in characteristics of the cows and management of lactations, as well as innovations in the management of the system have potential for increasing economic and environmental performances of grassland-based systems. The more systematic use of legume forages in multi-species swards makes it possible to reduce the consumption of mineral N, to reduce the carbon footprint of the dairy system, to regularize the forage production over the year and to increase the nutritional quality of the forages. It clearly appears that intensive selection for milk based on high concentrate diets has generally resulted in genotypes that are not well suited for systems maximising forage utilisation. In these systems there needs to be a special focus to address fertility, survival and other functional traits such as mastitis resistance, although high genetic merit for milk should be maintained to produce efficient responses to concentrate supply. Finally, extending the grazing season with early turnout or late grazing, and tactical use of grazing in association with conserved forages in large herds, offers many opportunities to reduce the requirement of expensive conserved forage and to reduce the utilisation of purchased feeds. All these potential sources of progress are discussed.
Simulation of the effect of grass intake on the farmer's income
Pol, A. van den; Haan, M.H.A. de; Evers, A.G. ; Philipsen, A.P. - \ 2010
In: Grassland in a changing world. Proceedings of the 23rd General Meeting of the European Grassland Federation, Kiel, Germany, 29th August - 2nd September 2010.. - Zürich, Switzerland : European Grassland Federation EGF - ISBN 9783869440200 - p. 100 - 102.
Grazing affects people, planet and profit. In general, the farmer's income will be higher when grazing of dairy cows is applied. We studied the economic effects of grazing for situations where we expect that grazing is difficult to apply. These situations could result in lower incomes for grazing. Farms with automatic milking systems, a small grazing surface, a large herd and/or a high milk yield per cow were studied. For the situations with automatic milking systems, large herds and high milk yields per cow, the farmer's income remained the highest for grazing. The difference between grazing and zero-grazing, however, was smaller than for farm situations without restrictions. In situations with more than 10 dairy cows ha" grazing surface, zero-grazing was more profitable than grazing. There was a strong relationship between intake of grass in pasture, on a typical farm, and the difference in income between grazing and zero-grazing. The more grass the cows eat in the pasture, the larger the income profit from grazing compared to zero-grazing.
Better grazing opportunities with a mobile milking robot
Haan, M.H.A. de; Philipsen, A.P. ; Pol, A. van den; Holshof, G. ; Lenssinck, F.A.J. ; Koning, C.J.A.M. de - \ 2010
In: 23th General Meeting of the European Grassland Federation, Kiel, Germany, 29 August - 02 September, 2010. - Zürich, Switzerland : European Grassland Federation EGF - ISBN 9783869440217 - p. 178 - 180.
Although grazing of dairy cows is very common in the Netherlands, the number of grazing cows is decreasing. Mobile milking robots might support grazing, in particular in situations of large herds, in remote grassland areas and in extensive natural grasslands. In the Netherlands, a stand-alone mobile milking robot has been developed using caterpillar tracks. Every day, this milking robot moves to a new part of the pasture and every two days concentrates, fuel, water and milk are separately transported from and to the mobile milking robot. The system was tested in the 2008 grazing season using a herd of 35 dairy cows. During the 2009 grazing season the project was scaled up to a herd of 60 cows on an area of 20 ha peat soil. In 2009 a strip grazing system with controlled as well as free cow traffic was used in order to increase the visit and milking frequency. The mobile milking robot was capable of managing a 60-cow herd grazing 24 hours while producing a rolling milk average of 7500 kg cow-1 yr-1. The challenge is to improve the milk yield per cow and year by increasing the milking frequency.
Changes in vegetation types and Ellenberg indicator values after 65 years of fertilizer application in the Rengen Grassland Experiment, Germany
Chytry, M. ; Hejcman, M. ; Hennekens, S.M. ; Schellberg, J. - \ 2009
Applied Vegetation Science 12 (2009)2. - ISSN 1402-2001 - p. 167 - 176.
species composition - field-measurements - hay meadows - classification - nitrogen - management - diversity - releves - availability - communities
Question: How does semi-natural grassland diversify after 65 years of differential application of Ca, N, P, and K fertilizers? Is fertilizer application adequately reflected by the Ellenberg indicator values (EIVs)? Location: Eifel Mountains, West Germany. Methods: The Rengen Grassland Experiment (RGE) was established in an oligotrophic grassland in 1941. Six fertilizer treatments (Ca, CaN, CaNP, CaNP- KCl, CaNP-K2SO4, and unfertilized control) were applied annually in five complete randomized blocks. Species composition of experimental plots was sampled in 2006 and compared with constancy tables representing grassland types in a phytosociological monograph of a wider area. Each plot was matched to the most similar community type using the Associa method. Mean EIVs were calculated for each treatment. Results: The control plots supported oligotrophic Nardus grassland of the Polygalo-Nardetum association (Violion caninae alliance). Vegetation in the Ca and CaN treatments mostly resembled montane meadow of Geranio-Trisetetum (Polygono-Trisetion). Transitional types between Poo-Trisetetum and Arrhenatheretum ( both from the Arrhenatherion alliance) developed in the CaNP treatment. In the CaNP- KCl and CaNP-K2SO4 treatments, vegetation corresponded to the mesotrophic Arrhenatheretum meadow. Major discontinuity in species composition was found between control, Ca, and CaN treatments, and all treatments with P application. EIVs for both nutrients and soil reaction were considerably higher in P treatments than in Ca and CaN treatments. Surprisingly, the control plots had the lowest EIVs for continentality and moisture, although these factors had not been manipulated in the experiment. Conclusions: Long-term fertilizer application can create different plant communities belonging to different phytosociological alliances and classes, even within a distance of a few meters. Due to their correlated nature, EIVs can erroneously indicate changes in factors that actually did not change, but co-varied with factors that did change. In P-limited ecosystems, EIVs for nutrients may indicate availability of P rather than N.
The Rengen Grassland Experiment: effect of long-term fertilizer application on diversification of plant communities
Hejcman, M. ; Schellberg, J. ; Chytrý, M. ; Hennekens, S.M. - \ 2008
In: Proceedings of 17th International Workshop European Vegetation Survey. Using phytosociological data to address ecological questions, Brno, Czech Republic, 1-5 May 2008. - Brno, Czech Republic : Masaryk University - ISBN 9788021045859 - p. 53 - 53.
|Quantification of uncertainty in climate change impact assessment
Downing, T.E. ; Barrow, E.M. ; Brooks, R.J. ; Butterfield, R.E. ; Carter, T.R. ; Harisson, P.A. ; Hulme, M. ; Oleson, J.E. ; Porter, J.R. ; Schellberg, J. ; Semenov, M.A. ; Vinther, F.P. ; Wheeler, T.R. ; Wolf, J. - \ 2000
In: Climate Change, Climatic Variability and Agriculture in Europe / Downing, T.E., Harrison, P.A., Butterfield, R.E., Lonsdale, K.G., Oxford, UK : Environmental Change Institute - ISBN 9781874370222 - p. 435 - 441.