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 A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>