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: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

127 at one blow...

18.01.2017 | Life Sciences

Brain-Computer Interface: What if computers could intuitively understand us

18.01.2017 | Information Technology

How gut bacteria can make us ill

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>