Analyse von GVO-Verunreinigungen in Bioprodukten: Belastungsgrade und Vermeidungsmöglichkeiten in Saatgut, Lebensmitteln und Futtermitteln

Die Bioproduktion erlaubt weltweit die Anwendung gentechnisch veränderter Organismen (GVO) und deren Folgeprodukte gemäss den international gültigen privaten und öffentlich rechtlichen Richtlinien nicht. Im Biolandbau werden zwar geschlossene Kreisläufe angestrebt, doch sind über viele Pfade Verunreinigungen mit GVO möglich (siehe Studie K. Nowack Heimgartner, R. Bickel, R. Pushparajah Lorenzen, E. Wyss (2002): Sicherung der gentechnikfreien Produktion. Eintrittswege gentechnisch veränderter Organismen, Gegenmassnahmen und Empfehlungen. Hrsg. Bundesamt für Umwelt, Wald und Landschaft (BUWAL). Schriftenreihe Umwelt Nr. 340). Die vorliegende Studie untersuchte den Stand der GVO-Verunreinigungen in biologischen Lebensmitteln, Futtermitteln und Saatgut in der Schweiz. Dazu wurden Firmen befragt und Analysedaten von privaten und öffentlichen Labor ausgewertet. Generell ist festzuhalten, dass die Schweiz eines der wenigen Länder ist, das praktisch gentechnikfrei ist: es werden keine gentechnisch veränderten Pflanzen in der Landwirtschaft angebaut und es wurden in den letzten Jahren keine Freisetzungsversuche bewilligt. Weder GVO-Lebensmittel noch GVO-Saatgut werden importiert, bei den Futtermitteln waren im Jahr 2002 weniger als 1% der gesamten Importe als GVO deklariert. GVO-Analysen bei Mais- und Sojaprodukten, die im Zeitraum von 2000 – 2002 von privaten und öffentlichen Labors in der Schweiz gemacht worden sind, zeigten, dass GVO Verunreinigungen bei Lebensmitteln bei etwa einem Drittel bis einem Viertel der Proben nachgewiesen werden konnten. Die Deklarationslimite von 1% wurde bis auf wenige Ausnahmen eingehalten. Der grosse Teil der Verunreinigungen lag im nicht quantifizierbaren Bereich von unter 0.1%. Allgemein sind Biolebensmittel weniger stark und weniger häufig verunreinigt als konventionelle. Der Unterschied ist jedoch klein. Die Untersuchung kann keine Aussage darüber machen, wieviele der verunreinigten Biolebensmittel dann auch tatsächlich als Bioprodukte vermarktet werden. Viele Firmen haben für Bioprodukte intern strengere Auflagen als die gesetzliche Deklarationslimite und leiten somit teilweise verunreinigte Bioprodukte in den konventionellen Kanal

Social dimensions of multifunctional agriculture in Europe - towards an interdisciplinary framework

Agriculture is embedded in and interacts with both its ecological and social environments. Under the concept of ‘Multifunctional Agriculture’, these interactions receive attention from scientific and political communities in terms of societal functions that can be fulfilled by farms. The discourse has focused on ecological functions, while agriculture’s social contributions are frequently mentioned but not systematically addressed. Accordingly, respective empirical results remain fragmented and applied conceptual approaches barely integrated. To address this research gap, we conducted a systematic literature review on the social functions of European agriculture. Our analysis (a) disentangles different definitions and categorizations of social functions found in the literature; (b) proposes an interdisciplinary framework and categorization that eases the linkage of relevant insights from different conceptual viewpoints; and (c) paves the way for the differentiated recognition and governance of the diverse social functions potentially delivered by farms and their activities in the European context.Peer Reviewe

Grüne Gentechnik und ökologische Landwirtschaft

Weltweit findet sich als Rechtsnorm in allen entsprechenden Verbraucherschutzgesetzen die Vorgabe, in der ökologischen Landwirtschaft keine gentechnisch veränderten Organismen einzusetzen. Auf europäischer Ebene enthalten weder die EU-Öko-Verordnung noch die Saatgutverkehrsrichtlinien Regelungen, aufgrund derer Schutzmaßnahmen zur Verhinderung oder Vermeidung von GVO-Einkreuzungen in ökologische Kulturen vorgeschrieben werden können. Eine Prüfung der neuen Freisetzungsrichtlinie ergibt aber, dass bei der Genehmigung zum Inverkehrbringen als „besondere Bedingungen für die Verwendung und Handhabung“ eines GVO auch Maßnahmen zum Schutz vor Sachschäden durch GVO-Einkreuzung vorgeschrieben werden können. Als Maßnahmen zum Schutz vor Sachschäden werden hauptsächlich Sicherheitsabstände zwischen Feldern mit GVO-Pflanzen und ökologisch bewirtschafteten Kulturen sowie zusätzlich gentechnikfreie Gebiete diskutiert. Bei der Analyse der Datenlage zur Definition von Sicherheitsabständen treten viele Lücken in der empirischen Datenbasis zu Tage, sodass sich hier dringender Forschungsbedarf abzeichnet. Es werden pragmatisch Hinweise zu Sicherheitsabständen abgeleitet. Gentechnikfreie Gebiete resp. geschlossene Anbaugebiete werden in Zusammenhang mit der Saatgutproduktion vorgeschlagen. Bisher ermöglicht nur das Zivilrecht in Deutschland einen privaten Ausgleich der Rechts- und Interessensphären der Bio-Bauern und der Nutzer transgener Sorten. § 906 BGB lässt sich hier als zentrale Steuerungsnorm des Umweltprivatrechts heranziehen. Dessen System von Unterlassungs- und Ausgleichsansprüchen ist hochkomplex und wird nur schwer zu einer zufriedenstellenden Koexistenz beitragen können. Eine Lösung wäre daher eine wirksame Selbstorganisation des Wirtschaftszweigs der Saatgutindustrie, die transgene Pflanzen züchtet und das Saatgut in Verkehr bringt. Sollte diese nicht möglich sein, bietet sich eine öffentlich-rechtliche Regelung an. Dazu könnten gehören: Die Einrichtung eines Anbaukatasters, die Einführung einer guten fachlichen Praxis des GVO-Anbaus (GfP), die Festlegung einer Instruktionspflicht auf der Saatgutverpackung sowie der Schutz der ökologischen Saatgutproduktion

Non-invasive evaluation of stress hormone responses in a captive population of sugar gliders (Petaurus breviceps)

Faecal hormone monitoring offers a robust tool to non-invasively determine the physiological stress experienced by an individual when faced with natural or human-driven stressors. Although already quantified for several species, the method needs to be validated for each new species to ensure reliable quantification of the respective glucocorticoids. Here we investigated whether measurement of faecal glucocorticoid metabolite (fGCM) provides a feasible and non-invasive way to assess the physiological state of sugar gliders (Petaurus breviceps), an arboreal marsupial native to Australia, by using both a biological and physiological validation. Our analysis confirmed that the cortisol enzyme immunoassay (EIA) was the most appropriate assay for monitoring fGCM concentrations in sugar gliders. Comparing the fGCM response to the physiological and the biological validation, we found that while the administration of ACTH led to a significant increase in fGCM concentration in all individuals, only six of eight individuals showed a considerable fGCM response following the biological validation. Our study identified the most appropriate immunoassay for monitoring fGCM concentrations as an indicator of physiological stress in sugar gliders, but also supports recent suggestions that, if possible, both biological and physiological stressors should be used when testing the suitability of an EIA for a species.Grants from the German Academic Exchange Service (DAAD) and the A.F.W. Schimper Stiftung für ökologische Forschung to J.N. and by the Australian Research Council and the University of New England to F.G.http://www.publish.csiro.au/amhj2019Anatomy and PhysiologyMammal Research Institut

Phoenix from the Ashes: Fire, Torpor, and the Evolution of Mammalian Endothermy

The evolution of endothermy in mammals and birds has been widely debated. Endothermy is characterized by high endogenous heat production via combustion of metabolic fuels. This differs from ectothermy in most living organisms, which generally do not produce substantial amounts of internal heat for thermoregulation (Tattersall et al., 2012; Withers et al., 2016). Endogenous heat production is energetically very costly. In comparison to ectothermic terrestrial vertebrates, namely the amphibians and reptiles, the minimum metabolic rate (MR) of normothermic or homeothermic (high constant body temperature, Tb) animals at rest is about 4–8-fold higher in the endotherms. This difference is even more pronounced at low ambient temperatures (Ta) at which the Tb of ectotherms follows Ta, and the MR decreases to even lower levels. In contrast, the Tb of homeothermic endotherms remains high and constant over a wide range of Ta. Therefore, to compensate for increased heat loss at low Ta, MR of especially small mammals and birds must increase substantially and can be 100-fold or more of that in ectotherms (Bartholomew, 1982). Of course this high MR requires a substantial uptake of food and in endotherms much of this chemical energy is simply converted into heat for thermoregulation rather than growth or reproduction as in ectotherms

The hustle and bustle of city life : monitoring the effects of urbanisation in the African lesser bushbaby

Urbanisation has become a severe threat to pristine natural areas, causing habitat loss and affecting indigenous animals. Species occurring within an urban fragmented landscape must cope with changes in vegetation type as well as high degrees of anthropogenic disturbance, both of which are possible key mechanisms contributing to behavioural changes and perceived stressors. We attempted to elucidate the effects of urbanisation on the African lesser bushbaby, Galago moholi, by (1) recording activity budgets and body condition (body mass index, BMI) of individuals of urban and rural populations and (2) further determining adrenocortical activity in both populations as a measure of stress via faecal glucocorticoid metabolite (fGCM) levels, following successful validation of an appropriate enzyme immunoassay test system (adrenocorticotropic hormone (ACTH) challenge test). We found that both sexes of the urban population had significantly higher BMIs than their rural counterparts, while urban females had significantly higher fGCM concentrations than rural females. While individuals in the urban population fed mainly on provisioned anthropogenic food sources and spent comparatively more time resting and engaging in aggressive interactions, rural individuals fed almost exclusively on tree exudates and spent more time moving between food sources. Although interactions with humans are likely to be lower in nocturnal than in diurnal species, our findings show that the impact of urbanisation on nocturnal species is still considerable, affecting a range of ecological and physiological aspects.Deutsche Forschungsgemeinschaft (DFG; DA 1031/3-1/2) and the DST-NRF SarchI Chair of Mammal Behavioural Ecology and Physiology.http://link.springer.com/journal/1142016-10-31hb201

Spicing up the menu : evidence of fruit feeding in Galago moholi

The African lesser bushbaby, Galago moholi, is currently described as a food specialist, feeding exclusively on small arthropods and gum primarily from Acacia karroo trees. We studied a population of G. moholi in a highly-fragmented habitat in the southernmost part of its natural distributional range in South Africa. In this habitat we opportunistically observed bushbabies feeding on fruits of the winter fruiting tree, Pappea capensis. Plot counts of tree composition revealed that although the dominant tree species in the area belonged to the genus Acacia, A. karroo trees were widely absent and gum could only be found in small quantities on other Acacia species. The analysis of P. capensis fruits showed high levels of protein, fat and energy content, making the fruits a potentially important food source for G. moholi during winter when insect availability is low. Our observation is the first documented case of fruit-feeding in G. moholi, suggesting that the species is not a food specialist as previously reported, but can opportunistically supplement its diet with fruit when available.Deutsche Forschungsgemeinschaft (DFG; DA 1031/3-1), the Department of Research and Innovation (University of Pretoria) and the DST-NRF SarchI Chair of Mammal Behavioural Ecology and Physiology.http://link.springer.com/journal/10329hb201

Female reproductive activity and its endocrine correlates in the African lesser bushbaby, Galago moholi

Steroid hormones play an important role in female reproductive physiology and behaviour and are often used to monitor important female reproductive events. However, such studies are often attempted on captive populations alone, delivering limited data. One such example is the African lesser bushbaby, Galago moholi, for which contradicting observational data exist between captive and free-ranging populations, while hormonal analyses have only been obtained from a single captive population. To extend and rectify the limited information, we monitored faecal progestagen and oestrogen metabolite levels across various important life history stages of both captive and free-ranging G. moholi. We additionally recorded changes in vaginal state as well as the occurrence of reproductive and aggressive behaviour throughout the study. Data from our captive population revealed an ovarian cycle length of 33.44 ± 0.59 days (mean ± SD), with follicular and luteal phases of 14.2 ± 1.0 and 19.1 ± 1.5 days, respectively, and an average pregnancy length of 128 ± 3.3 days. The initiation of female reproductive activity was closely linked to an oestrus-related increase in faecal oestrogen metabolite levels. Four of the seven captive females monitored in our study conceived during the May mating period, with one additional female fertilised in September, supporting the idea that the September mating period functions as a back-up for female G. moholi. Identified benchmark faecal progestagen metabolite levels (non-pregnant: >1 μg/g dry weight (DW), pregnant: >9 μg/g DW) should help researchers to determine pregnancy status of randomly wild-caught females in even a cross-sectional study setup.Deutsche Forschungsgemeinschaft (DFG; DA 1031/3-1/2) and the DST-NRF SarchI Chair of Mammal Behavioural Ecology and Physiology.http://link.springer.com/journal/3602017-02-28hb201

Cardiovascular effects of intravenous vatinoxan in wild boars (Sus scrofa) anaesthetised with intramuscular medetomidine-tiletamine-zolazepam

Background The potent sedative medetomidine is a commonly used adjunct for the immobilisation of non-domestic mammals. However, its use is associated with pronounced cardiovascular side effects, such as bradycardia, vasoconstriction and decreased cardiac output. We investigated the effects of the peripherally-acting alpha-2-adrenoceptor antagonist vatinoxan on cardiovascular properties in medetomidine-tiletamine-zolazepam anaesthetised wild boar (Sus scrofa). Methods Twelve wild boars, anaesthetised twice with medetomidine (0.1 mg/kg) and tiletamine/zolazepam (2.5 mg/kg) IM in a randomised, crossover study, were administered (0.1 mg/kg) vatinoxan or an equivalent volume of saline IV (control). Cardiovascular variables, including heart rate (HR), mean arterial blood pressure (MAP), pulmonary artery pressure (PAP), pulmonary artery occlusion pressure (PAOP) and cardiac output (CO), were assessed 5 min prior to vatinoxan/saline administration until the end of anaesthesia 30 min later. Results MAP (p < 0.0001), MPAP (p < 0.001) and MPAOP (p < 0.0001) significantly decreased from baseline after vatinoxan until the end of anaesthesia. HR increased significantly (p < 0.0001) from baseline after vatinoxan administration. However, the effect on HR subsided 3 min after vatinoxan. All variables remained constant after saline injection. There was no significant effect of vatinoxan or saline on CO. Conclusion Vatinoxan significantly reduced systemic and pulmonary artery hypertension, induced by medetomidine in wild boar.Peer reviewe