Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New approach for environmental test on livestock drugs

27.07.2016

Drugs for livestock can harm beneficial organisms that break down dung. Therefore newly developed medical substances need to be tested on single species in the lab. An international research group including evolutionary biologists from the University of Zurich have been scrutinizing the reliability of such laboratory tests, evaluating the implementation of a field test based on the anti-parasitic drug ivermectin at four climatically different locations. The scientists thus presented a novel approach for more advanced environmental compatibility tests.

Livestock medications can impair beneficial organisms that break down dung. Too high a dosage of ivermectin, a common drug against parasites, harms coprophilous organisms, for instance. The toxicity of new livestock medications therefore needs to be verified in ecotoxicological tests with individual animal species such as the common yellow dung fly, the barn fly or a dung beetle.


Dung pat with a specific concentration of ivermectin.

Image: UZH

This involves determining the lethal dose leading to the death of half the maggots (LD50 test). However, sensitivity to toxic substances is known to vary significantly even among closely related coprophilous organisms, which begs the question as to how representative the reaction of any individual animal species actually is in such laboratory tests. After all, there is a high risk that more sensitive species will continue to be harmed by the substance, jeopardizing key ecosystem functions in the long run.

An international research group including UZH evolutionary biologist Wolf Blanckenhorn recently proposed extending the testing scheme to a representative selection of all organisms that break down dung, ideally in their natural environment. The scientists now presented a successful and more comprehensive higher-tier ecotoxicological field test. Their study provides important insights into minimizing the risks of drug residues in nature.

Earthworms compensate for loss of coprophilous insects

For their feasibility study, the scientists worked on cattle pastures in the Canadian Prairie and the agricultural landscapes of southern France, the Netherlands and Switzerland – four locations with very different climatic conditions. On these pastures, they distributed dung pats with different concentrations of ivermectin. “As expected, the overall number and diversity of dung beetles, dung flies and parasitoid wasps decreased as the ivermectin concentration increased,” explains Blanckenhorn.

However, a number of species also proved to be resistant: earthworms and springtails living in the ground underneath the cowpats were not notably affected, and a parallel test ultimately revealed that dung degradation was not significantly impaired. “Evidently, beneficial organisms not affected as much by the drug, such as earthworms, were apparently able to compensate for the loss of other organisms,” sums up Blanckenhorn.

A basis for decision makers and licensing authorities

Despite diverse environmental conditions and methodological details, the results were very similar and reproducible in all four habitats. “Our field approach was therefore a success and in principle can be recommended. The regulation authorities responsible, such as the European Medicines Agency EMA, now have to decide whether this more conclusive yet more complex test should be required in the future,” says Blanckenhorn.

The amount of effort involved in determining the numerous dung organisms is tremendous and impossible without expert biological knowledge. “Classifying species via so-called DNA barcoding, based on each organism’s unique genetic fingerprint, is possible in principle and will probably be more cost-effective in the future. However, this approach requires the establishment of a complete database for coprophilous organisms, which does not yet exist,” concludes the scientist.

Literature:

Kevin D. Floate, Wolf U. Blanckenhorn. Special Section: Non-target Structural and Functional Effects of Ivermectin Residues in Cattle Dung on Pasture – Guidance for Researchers and Regulators. Environmental Toxicology and Chemistry. Volume 35, Issue 8. July 21, 2016. DOI: 10.1002/etc.3549


Ivermectin

Scientists discovered and refined ivermectin in Japan in the mid-1970s, eventually winning the Nobel Prize in Medicine in 2015. The drug has been used to cure river blindness, scabies and roundworms in the gut of humans, as well as parasites in livestock and pets.

Chemically ivermectin belongs to the avermectins, which generally interfere with ion channel transport through the cell membrane and thus the molting of pest organisms. If the ivermectin dosage is too high and excreted in the feces of treated livestock, the drug also kills beneficial organisms that break down dung. This has a negative impact on the functioning of the entire ecosystem: in extreme cases, the dung is no longer degraded at all and the pasture cannot be used any further.

Contact:

Prof. Dr. Wolf U. Blanckenhorn
Department of Evolutionary Biology and Environmental Studies
University of Zurich
Phone: +41 44 635 47 55
E-mail: wolf.blanckenhorn@ieu.uzh.ch

Media Relations
University of Zurich
Phone: +41 44 634 44 67
E-mail: mediarelations@kommunikation.uzh.ch

Weitere Informationen:

http://www.media.uzh.ch/en/Press-Releases/2016/New-approach-for-environmental-te...

Nathalie Huber | Universität Zürich

Further reports about: Ecosystem Environmental Phone animal species conditions dosage drugs earthworms fly parasites species

More articles from Ecology, The Environment and Conservation:

nachricht When corals eat plastics
24.05.2018 | Justus-Liebig-Universität Gießen

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

When corals eat plastics

24.05.2018 | Ecology, The Environment and Conservation

Surgery involving ultrasound energy found to treat high blood pressure

24.05.2018 | Medical Engineering

First chip-scale broadband optical system that can sense molecules in the mid-IR

24.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>