. Energy News .

Even for cows, less can be more
by Susan Jongeneel for UI News
Urbana IL (SPX) Aug 19, 2013

File image.

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.


Related Links
University of Illinois College of Agricultural, Consumer and Environmental Sciences
Farming Today - Suppliers and Technology

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Get Our Free Newsletters
Space - Defense - Environment - Energy - Solar - Nuclear


Researchers discover protein that helps plants tolerate drought, flooding, other stresses
Hanover, NH (SPX) Aug 19, 2013
A team including Dartmouth researchers has uncovered a protein that plays a vital role in how plant roots use water and nutrients, a key step in improving the production and quality of crops and biofuels. The findings appear this week in the journal PNAS. The team included researchers from Dartmouth, the University of Aberdeen and the University of Lausanne. Plant roots use their end ... read more

Thai villagers mistake Google worker for government snoop

Norway says no to Apple request to photograph Oslo for 3-D maps

Africa's ups and downs

Lockheed Completes Solar UV Imager For GOES-R Enviro Tests

Satellite tracking of zebra migrations in Africa is conservation aid

'Spoofing' attack test takes over ship's GPS navigation at sea

Orbcomm Globaltrak Completes Shipment Of Fuel Monitoring Solution In Afghanistan

Lockheed Martin GPS III Satellite Prototype To Help Cape Canaveral Air Force Station Prep For Launch

One tree's architecture reveals secrets of a forest

Could planting trees in the desert mitigate climate change

Wasps being used to fight tree disease

Drought making trees more susceptible to dying in forest fires

New possibilities for efficient biofuel production

Microbial Who-Done-It For Biofuels

Microorganisms found in salt flats could offer new path to green hydrogen fuel

CSU researchers explore creating biofuels through photosynthesis

White House goes green with solar panels

Japan's grids can support solar boom?

Can solar energy help save Greece?

Empa scientists boost CdTe solar cell efficiency

Localized wind power blowing more near homes, farms and factories

Price of Wind Energy in the United States Is Near an All-Time Low

GDF Suez sells half-share of Portuguese renewable, thermal holdings

SOWITEC Mexico - strengthening its permitted project pipeline

Australia's coal sector enduring toughest operating environment

Greenpeace warns water pollution from German coal mining on the rise

Greenpeace says Chinese coal company exploiting water

Major China coal plant drains lake, wells: Greenpeace

China high-flyer Bo brought low as trial finally nears

China removes top judge in Bo-linked case

China in a pickle over migration statistics

China issues guidelines to prevent wrong court judgements

The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement