Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sweeter grass does not lead to more milk

22.09.2004


Contrary to general expectations, the characteristics of different varieties of perennial ryegrass such as sugar content do not influence the feed intake of grazing dairy cows. Moreover cell wall degradability characteristics were not different among perennial ryegrass varieties. Research carried out by the Palestinian researcher Hassan Z. H. Taweel at Wageningen University, Netherlands, shows that an increased dry matter intake can be achieved by gaining more insight into the regulatory mechanisms behind the maximum use of rumen capacity. Taweel defended his doctoral thesis Perennial Ryegrass for Dairy Cows: Grazing Behaviour, Intake, Rumen Function and Performance at Wageningen University.



In highly productive grazing dairy stock, dry matter intake (and consequently protein and energy intake) is a limiting factor in milk production. To augment milk production, grazing dairy cattle are therefore generally given supplements of feed concentrates and energy-rich maize silage.

In his study in Wageningen, researcher Taweel examined eating motivation as well as the capacity and rate of digestion in the rumen of dairy cattle. The first hypothesis was that eating motivation is strongly related to taste, and that tastiness is primarily determined by sugar, i.e., water-soluble carbohydrates (WSC) content. The second hypothesis was that plants with more easily digestible cell walls pass through the rumen faster, and the expectation was that this increased the processing capacity and hence grass intake.


Taweel carried out experiments feeding various ryegrass varieties to dairy cows under stall-feeding and grazing conditions. in each experiment, a single variety of ryegrass was available ad libitum for periods of two weeks. The varieties were all commercially available and selected for their varying WSC content. The researcher also examined differences in cell wall degradability of the ryegrass varieties.

No significant differences in grass intake or milk yield due to different grass varieties were observed. The experiment concluded that WSC levels did not affect the voluntary feed intake of the animals, and that relative differences in degradability of cell walls were very small and offered few perspectives to improve intake. Varieties with a high sugar content did result in reduced ammonia content in the rumen and lower urea levels in milk, which is interesting for N-surplus reduction issues in dairy farms. Recent research at Wageningen University (in partnership with NIZO food research) also showed that cows eating fresh grass produce milk with a healthier composition of fatty acids than cows that are fed on silage.

Follow-up research by Taweel into grazing periods during the day and rumen capacity also yielded groundbreaking results. Grazing cows feed during three main periods in a day - early in the morning, around midday and at sunset - during each of which they continuously graze for more than an hour. Interestingly, however, the evening grazing went on for a much longer time than the others. This led Taweel to study rumen fill, which is considered one of the factors that end a grazing period. He found that the rumen was entirely full only at midnight. This implied that, at other moments during the day, cows stopped grazing long before reaching maximum rumen capacity.

Further research will be necessary to find out the reason for this behaviour. If cows would use their full maximum potential of rumen fill during the morning and afternoon grazing periods, this could result in higher intake and therefore absorption of energy from fresh grass, and, hence, in increased milk production.

Jac Niessen | alfa
Further information:
http://www.wageningen-ur.nl

More articles from Agricultural and Forestry Science:

nachricht Energy crop production on conservation lands may not boost greenhouse gases
13.03.2017 | Penn State

nachricht How nature creates forest diversity
07.03.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short

23.03.2017 | Life Sciences

Researchers use light to remotely control curvature of plastics

23.03.2017 | Power and Electrical Engineering

Sea ice extent sinks to record lows at both poles

23.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>