103 research outputs found

    Helminth eggs die-off and nutrients : human excreta storage experiment

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    Are the current practices of handling human excreta for agricultural purposes by farmers in Vietnam good enough?This study set up an excreta storage experiment to research how to inactivate Ascaris lumbricoides eggs and stillmaintain the nutrient value of human excreta

    Black soldier fly larvae as a substitute for soybean in the diets of laying hens

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    The use of soybean as a feed ingredient for livestock is controversially discussed worldwide, since cultivation and transport may have negative environmental impacts. Thus, interest in integrating insects into livestock nutrition as a potentially more sustainable substitute for soybean is very important, but has been poorly researched so far. This study aimed to examine the feeding value of two origins of black soldier fly (BSF) larvae grown on two different substrates (A and B) compared to soybeanbased diets. For this purpose, 50 Lohmann Brown Classic hens (40 weeks of age) were fed five different diets for 7 weeks. The hens were randomly allocated to the diets and kept individually in enriched cages under controlled climate conditions. To determine whether the protein value of the insect material is comparable to that of soybean, the crude protein content of four of the diets (SS-, AA-, AB-, BB-) was set to a level (16%). These diets were opposed to a control diet (SS) covering requirements. Both SS and SS- contained 15% soybean cake and 3% soybean oil, but SS- did not contain sunflower cake. In the other diets the soybean-based feeds from SS- were replaced by defatted BSF larval meals and fats. Insect material A was produced on a mixture of fruits, brewer’s grain and pasta production waste, material B was produced on wheat bran, French fries and cereal milling by-products. Diet AA- contained 15% of larval meal A and 2% larval oil A, AB- was based on 15% larval meal A and 2% larval fat B, and BB- contained 15% of larval meal B (rich in residual fat). Feed intake, laying performance and egg weight were measured daily. The hens were weighed weekly. Over a period of six days all eggs per hen were collected and analysed for different egg quality traits. The performance of the hens did not differ significantly between the five treatments within the feeding period. Average feed intake was around 118 g/day, laying percentage 95%, egg weight 65 g and feed conversion efficiency 1.9 g egg/kg feed. Also, egg quality was neither affected by the use of insects nor the apparent protein deficiency. Average shell thickness was 0.4 mm, yolk height 17 mm and shell breaking strength 50 N. Overall, the similar performance of the hens at a very high production level and the comparable egg quality showed that soybean can be completely replaced by BSF meal and fat. The results also indicated that the recommendations for protein supply of layers may be set too high

    Black soldier fly larvae meal and fat can completely replace soybean cake and oil in diets for laying hens

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    Currently, there is a great interest in finding alternative protein and energy sources to replace soybean-based feeds in poultry diets. The main objective of the present study was to completely replace soybean in layer diets with defatted meal and fat from black soldier fly larvae without adverse effects. For this purpose, 5 × 10 Lohmann Brown Classic hens were fed either a soybean-based diet or diets based on defatted black soldier fly larvae meal and fat from 2 producers (1 commercial, 1 small-scale) operating with different rearing substrates, temperatures, and larvae processing methods (10 hens/diet). The data obtained included nutrient composition of larvae meals and diets, amino acid digestibility (6 hens/diet), and metabolizability, performance and egg quality (all 10 hens/diet). In addition, the acceptance of the 4 larvae-based diets was tested against the soybean-based diet in a 6-day choice feeding situation (10 hens/treatment). The nutritional value of the larvae-based diets was equivalent to the soybean-based diet in hens with a laying performance of 98%. Although average feed intake was not significantly different over the 7 experimental weeks, the diets based on larvae feeds from the small-scale production appeared to be slightly less accepted in a choice situation than the soy-based diet and those with larvae from commercial origin. This was more likely the effect of the larvae fat rather than that of the larvae protein meal. In addition, the commercial larvae material was superior to that from the small-scale production concerning supply with digestible sulfur-containing amino acids (548 vs. 511 mg/day) and lysine (792 vs. 693 mg/day), egg weight (67 vs. 63 g), daily egg mass (66 vs. 61 g/day) and, in tendency, feed efficiency. The results indicate that soybean-based feeds can be replaced completely by black soldier fly meal and fat in diets of high-performing layers. However, because of nutritional differences between the larvae materials of different origin the quality of the larvae has to be closely monitored before being used

    Social processes in post-crisis municipal solid waste management innovations: A proposal for research and knowledge exchange in South Asia

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    Municipal solid waste management (MSWM) has become one of the most pressing environmental issues in South Asian cities, the more so as it is closely linked to drinking water quality, sanitation and human health affecting mostly the urban poor, as well as to global climate change. Looking at recent governance initiatives in three South Asian cities developed in the wake of natural or human-induced crises, the project will focus on how to render MSWM improvements politically feasible and socially acceptable, which is a pre-requisites for functioning SWM systems, and thus for (environmental and social) sustainability more generally. The goal of this project, therefore, is to identify, analyze and promote the political and sociocultural processes that are necessary to enable the functioning of MSWM systems. In particular, alternative practices and systems are promoted, whereby institutional hierarchies are decentralized, favoring horizontal accountabilities and whereby waste chains are shortened and transformed into closed loops implying a more circular waste economy in which both environmental and local livelihood benefits would accrue. The project puts emphasis on mutual learning through horizontal South-South partnerships between local authorities, civil society actors and researchers across South Asia

    Low transfer of cadmium, lead and aflatoxin B1 to eggs and meat of laying hens receiving diets with black soldier fly larvae reared on contaminated substrates

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    Replacing soybeans with insects in egg and poultry meat production could improve environmental sustainability. Black soldier fly larvae (BSFL) have a favorable nutrient composition and can be reared on low-grade waste, but this is associated with the risk of feed and food contamination. The aim of this study was to assess the transfer of selected contaminants from larval substrates to poultry-derived food. Two different control substrates were used. Substrate CCH (produced in Switzerland) was based on side streams approved for insect rearing in the European Union (EU), while substrate CIND (produced in Indonesia) included non-EU approved waste. In addition, substrate CIND was spiked with either heavy metals (HM; 1.9 mg cadmium and 18.8 mg lead/kg dry matter (DM)) or 1.5 mg aflatoxin B1/kg DM (AF)). The larvae fed HM contained 7 mg cadmium and 16 mg lead/kg DM. These values were about 30 times the concentrations of cadmium and 30–60 times the concentrations of lead found on average in the BSFL reared with the two non-spiked substrates. Although substrate AF contained 842 μg aflatoxin B1/kg DM as analysed, the AF larvae contained only 4 μg aflatoxin B1/kg DM. Larval meals were integrated at 200 g/kg in two control diets (diets CCH and CIND) and two diets based on contaminated BSFL (diets HM and AF) designed for late-laying hens (n = 9/treatment). After feeding these diets for 4 weeks, the hens were slaughtered. Diet HM and AF did not affect laying performance or egg quality compared with the control diets. In the body tissue, the cadmium concentrations (per kg DM) were nearly doubled by diet HM in the breast meat (13.3 μg), kidneys (12.3 mg) and liver (1.86 mg) compared to diet CIND. The same diet increased lead in kidneys from below 0.1 to 0.5 mg/kg DM. No lead was detected in the meat and eggs, and no cadmium was found in the eggs. In conclusion, despite cadmium and lead also occurring in BSFL meals of CCH and CIND, the levels in all corresponding hen-based feed and food materials were below the maximum content, except for the kidneys. The aflatoxin B1 level of diet AF (1 μg/kg DM) suggests that the risk might also be small when BSFL are reared on moldy substrate containing aflatoxin-producing fungi. In conclusion, postconsumer waste apparently poses a lower risk than expected in poultry food chains for these contaminants when used as larval substrate

    奥付

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    This chapter discusses a conceptual framework for integrated health and environmental assessment that combines health status, and the physical, socioeconomic and cultural environments in order to improve human health and minimize environmental impact. This concept's application in the management of human and animal excreta in Vietnam is then described

    No Adverse Effect of Genetically Modified Antifungal Wheat on Decomposition Dynamics and the Soil Fauna Community – A Field Study

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    The cultivation of genetically modified (GM) plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b) and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C∶N ratio, lignin, cellulose, hemicellulose) were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina), springtails (Isotomidae), annelids (Enchytraeidae) and Diptera (Cecidomyiidae larvae). Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM wheat on the composition and the activity of the soil fauna community

    Recommendations for the design of laboratory studies on non-target arthropods for risk assessment of genetically engineered plants

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    This paper provides recommendations on experimental design for early-tier laboratory studies used in risk assessments to evaluate potential adverse impacts of arthropod-resistant genetically engineered (GE) plants on non-target arthropods (NTAs). While we rely heavily on the currently used proteins from Bacillus thuringiensis (Bt) in this discussion, the concepts apply to other arthropod-active proteins. A risk may exist if the newly acquired trait of the GE plant has adverse effects on NTAs when they are exposed to the arthropod-active protein. Typically, the risk assessment follows a tiered approach that starts with laboratory studies under worst-case exposure conditions; such studies have a high ability to detect adverse effects on non-target species. Clear guidance on how such data are produced in laboratory studies assists the product developers and risk assessors. The studies should be reproducible and test clearly defined risk hypotheses. These properties contribute to the robustness of, and confidence in, environmental risk assessments for GE plants. Data from NTA studies, collected during the analysis phase of an environmental risk assessment, are critical to the outcome of the assessment and ultimately the decision taken by regulatory authorities on the release of a GE plant. Confidence in the results of early-tier laboratory studies is a precondition for the acceptance of data across regulatory jurisdictions and should encourage agencies to share useful information and thus avoid redundant testing
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