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 Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University

nachricht New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien

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: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>