Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Even for cows, less can be more

14.08.2013
With little research on how nutrition affects reproductive performance in dairy cows, it is generally believed that a cow needs a higher energy intake before calving. Research by University of Illinois scientists challenges this accepted wisdom.

Animal sciences researcher Phil Cardoso said that this line of research was the result of an "accident." Students in animal sciences professor James Drackley's group compared cows fed before calving with diets containing the recommended energy levels to cows fed reduced energy diets. They found that the cows fed the reduced energy diets performed better after calving.

Cardoso, intrigued by those results, wondered if diet might also be linked to reproductive performance. Using data from seven experiments completed at the U of I from 1993 to 2010, he constructed a database of 408 cows containing data on prepartum diet and physiological status. He also looked at days to next pregnancy (DTP) after calving, which had not been considered in previous studies.

He found that, on average, cows fed the controlled energy (CE) diets (80% of the recommended amount) became pregnant about 10 days sooner than cows fed high-energy (HE) diets, an average time period of 157 versus 167 days.

"People say that if you give this CE diet, the cows don't get pregnant, but that's not true," he said. "If anything, they are a little better off."

They also lost less in body condition score (BCS) and had a lower disease incidence because they were eating more.

Cardoso said that the shorter time to conception for cows fed the CE diet is due to the fact that they eat more after calving than the cows fed the HE diet.

"Just after calving, the cows have a negative energy balance (NEB)," he explained. This is because they cannot consume enough energy to compensate for the fact that they are producing milk.

This NEB, which can be measured by looking at metabolites in the blood, causes them to lose weight, lowering their BCS. High levels of the metabolites just before calving or one to two weeks after calving are associated with metabolic disorders and certain diseases, which cause them to eat less. These in turn affect reproductive performance.

Both groups of cows showed reduced energy consumption around calving due to stress, but the drop was 4 times, or approximately 30 percent, higher in the HE cows and only 7 percent in the CE cows.

Cows fed the CE diet were able to start eating right after calving. "We want the cow to eat as much as possible just after calving because then she's going to be healthier," Cardoso said.

The researchers also noticed that cows fed the CE diet showed less prepartum versus postpartum variation in how much they ate. By contrast, the cows fed the high energy diet were eating more than they needed before calving.

"Cows and ruminants cannot export well from the liver," said Cardoso. "Any time a large amount of fat is going to the liver, that's going to cause a lot of problems. They are going to have lower levels of glucose and ketone bodies will form. Feed intake will start to drop, and the cow will start feeling ill."

In a follow-up study that has not yet been published, the researchers tried to strategies to make the cows eat less. One was to give them just 80 percent of what they needed; the other was to increase fiber in the day so the diet would be lower in energy and the cows could eat more. They had similar results for the two strategies.

There are indications that a CE diet has other benefits. It may help food to remain longer in the rumen, which is beneficial to the cow if she is stressed.

In short, Cardoso advised, just give the cow what she needs and she will perform better metabolically and reproductively.

"There is money associated with this," he said. "Any disease costs money."

But long intervals between calvings also costs money. "In the dairy business, we'd like the cow to calve once a year and the calving interval to be around 12 to 13 months. Because to give milk, she needs to calve, so we want her pregnant as soon as possible," Cardoso explained.

He added that research has shown that every day after 90 days in milk that the cow does not get pregnant represents a cost of 2 to 3 dollars.

"Prepartum Dietary Energy and Reproduction" by F.C. Cardoso, S.J. LeBlanc, M.R. Murphy, and J.K. Drackley, has recently been published in Journal of Dairy Science and is available at http://www.journalofdairyscience.org/article/S0022-0302%2813%2900465-7/abstract.

This article was originally written by Susan Jongeneel.

Stephanie Henry | EurekAlert!
Further information:
http://www.illinois.edu

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | 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

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>