Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Choosing organic milk could offset effects of climate change

17.01.2011
Wetter, cooler summers can have a detrimental effect on the milk we drink, according to new research published by Newcastle University.

Researchers found milk collected during a particularly poor UK summer and the following winter had significantly higher saturated fat content and far less beneficial fatty acids than in a more 'normal' year.

But they also discovered that switching to organic milk could help overcome these problems. Organic supermarket milk showed higher levels of nutritionally beneficial fatty acids compared with 'ordinary' milk regardless of the time of year or weather conditions.

The study, which is published in this month's Journal of Dairy Science (January 2011), leads on from previous research undertaken nearly three years ago which looked at the difference between organic and conventional milk at its source – on the farms.

"We wanted to check if what we found on farms also applies to milk available in the shops," said Gillian Butler, who led the study. "Surprisingly, the differences between organic and conventional milk were even more marked. Whereas on the farms the benefits of organic milk were proven in the summer but not the winter, in the supermarkets it is significantly better quality year round."

There was also greater consistency between organic suppliers, where the conventional milk brands were of variable quality.

"We were surprised to see obvious differences between the conventional brands, with the more expensive ones not necessarily better," said Mrs Butler. "Some brands - which promote their suppliers as wholesome and grazing on fresh pastures - actually sold milk that appeared to be from very intensive farms."

Low levels of omega-3 and polyunsaturated fatty acids were discovered in some of these brands, which are indicative of a diet low in fresh grass. These samples also showed evidence of the cows being supplemented with a saturated fat product derived from palm oil.

Mrs Butler puts the differences down to a lower reliance on grazing and fertiliser suppressing clover on conventional farms. "The results suggest greater uniformity of feeding practice on farms supplying organic milk since there were no brands which differed consistently in fat composition," she said. "This implies a fairly uniform approach to feeding practised across these suppliers."

Organic dairying standards prescribe a reliance on forage, especially grazing, and, in the absence of nitrogen fertiliser, tend to encourage swards of red and white clover, which have been shown to alter the fatty acid intake and composition of milk.

While protein, antioxidants, vitamins, minerals and some mono and polyunsaturated fatty acids in milk are considered beneficial, saturated fatty acids are believed to have a negative effect on human health.

"We're always being told to cut down on the saturated fat we consume and switching to organic milk and dairy products provides a natural way to increase our intake of nutritionally desirable fatty acids, vitamins and antioxidants without increasing our intake of less desirable fatty acids," said Mrs Butler.

"By choosing organic milk you can cut saturated fats by 30-50 percent and still get the same intake of beneficial fatty acids, as the omega-3 levels are higher but omega-6 is not, which helps to improve the crucial ratio between the two."

While undertaking their research into the differences between organic and conventional milk, the researchers discovered the surprising link between milk quality and our changing climate. Their results suggest that if we continue to have wetter, cooler summers then farmers may have to rethink their current dairy practices.

There was a considerable difference between the milk bought in the first sampling period (July 2006 and January 2007) and corresponding times a year later. The second set of samples, following a particularly wet summer in 2007, was higher in saturated fat and lower in beneficial fatty acids.

"We didn't expect to find differences between the sampling periods," said Mrs Butler. "But this is likely to be down to the impact of the weather on availability and quality of forage."

In North East England, for example, the summer of 2007 was particularly wet, with approximately 30 per cent higher recorded rainfall and 12 per cent lower temperatures compared with 2006.

"These conditions may affect the cows' behaviour, reducing grazing intake and milk output," said Mrs Butler. "Farmers also often increase supplementation with concentrated feeds or conserved forage to maintain milk yields in these conditions."

During the region's main silage making period (late May until the end of July) rainfall in 2007 was three times higher than the previous year, which also made for poorer quality silage and therefore the need for greater supplementation to compensate in winter diets.

"If these weather patterns continue, both forage and dairy management will have to adapt to maintain current milk quality," said Mrs Butler. "The higher levels of beneficial fats in organic milk would more than compensate for the depression brought about by relatively poor weather conditions in the wet year."

The researchers, who are part of the University's Nafferton Ecological Farming Group and its Human Nutrition Centre, looked at the quality of milk in supermarkets across North East England at varying times of year over a two-year period.

They concluded that organic brands of milk available in supermarkets are higher in beneficial fatty acids such as CLA and omega-3 fatty acids in summer (as in their previous research) and winter (where previous research showed that the difference in the winter was not as noticeable).

Emma Hockridge, head of policy at the Soil Association, said: "This groundbreaking research proves for the first time that people buying organic milk will be benefitting from the higher levels of beneficial fatty acids in organic milk through the whole year."

Sarah Cossom | EurekAlert!
Further information:
http://www.ncl.ac.uk

More articles from Studies and Analyses:

nachricht Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont

All articles from Studies and Analyses >>>

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 >>>