407 research outputs found
Replacement of soybean cake by Hermetia illucens meal in diets for layers
Insects will likely play an important role as protein sources for livestock in the future. Many insect species are able to convert materials not suitable for human nutrition – or even waste – into valuable protein with a favourable amino acid composition for poultry and other livestock. A feeding trial with partly de-fatted meal of dried Hermetia illucens larvae (Hermetia meal) reared on vegetarian by-products of the pasta and convenience food industry was carried out in small groups of Lohmann Selected Leghorn laying hens (four rounds, 10 hens/round). Experimental diets H12 and H24 contained 12 and 24 g/100 g Hermetia meal replacing 50 or 100% of soybean cake used in the control feed, respectively. After three weeks of feeding experimental diets, there were no significant differences between feeding groups with regard to performance (egg production, feed intake). There was a tendency (P=0.06) for lower albumen weight in the H24 group; yolk and shell weights did not differ. No mortality and no sign of health disorders occurred. Plumage as well as wound scores remained stable during the feeding period and did not differ between treatments. Dry matter of faeces increased with increasing proportions of Hermetia meal in the diet, with a significant difference between H24 and the control (P=0.03). An increase of black faecal pads was observed in the H12 and H24 groups. Overall, these results suggest Hermetia meal can be a valuable component of layer diets.
However, insect meal production still has to become economically more viable through upscaling production and, especially, legislative issues have to be solved
Feeding value of black soldier fly larvae compared to soybean in methionine- and lysine-deficient laying hen diets
To increase the sustainability of egg production, alternatives to soybean in poultry nutrition are intensively searched for. Black soldier fly larvae (BSFL) could have a great potential, but the comparative protein value to soybean is not well known. The main objective of this study was to facilitate this comparison by using experimental diets clearly limited in calculated supply of sulphurous amino acids and lysine. Fifty laying hens (Lohmann Brown Classic), aged 40 weeks, were fed one of five diets for 7 weeks (n=10). Two diets were based on soybean cake and oil (SS, SS-) as protein and energy sources, and three diets contained partially defatted BSFL meal and fat from two different origins (AA-, AB-, BB-). Different from SS, all other diets were designed to be deficient in methionine and lysine in relation to requirements by >20%. The realised supply with total sulphurous amino acids and lysine was indeed superior with SS even though this diet was analysed to be more deficient in methionine than the BSFL-based diets. Despite the calculated deficiency in limiting amino acids, laying performance of the hens of all groups was similar and ranged between 93 and 97%. Similarly, egg mass, daily feed intake and feed efficiency were not influenced by the BSFL-based diets. The yolks of group BB- were more intensely coloured compared to the others indicating a difference between BSFL origins. Yolks of SS-, but not of the BSFL-based diets, had lower contents of dry matter and ether extract than those of SS. Including BSFL into the diet did not influence the odour of the eggs tested in scrambled form. The results show that soybean-based feeds for laying hens may be completely replaced by BSFL- based feeds and suggest that the recommendations for amino acid supply of laying hens might need revision
Technical design and commissioning of the KATRIN large-volume air coil system
The KATRIN experiment is a next-generation direct neutrino mass experiment
with a sensitivity of 0.2 eV (90% C.L.) to the effective mass of the electron
neutrino. It measures the tritium -decay spectrum close to its endpoint
with a spectrometer based on the MAC-E filter technique. The -decay
electrons are guided by a magnetic field that operates in the mT range in the
central spectrometer volume; it is fine-tuned by a large-volume air coil system
surrounding the spectrometer vessel. The purpose of the system is to provide
optimal transmission properties for signal electrons and to achieve efficient
magnetic shielding against background. In this paper we describe the technical
design of the air coil system, including its mechanical and electrical
properties. We outline the importance of its versatile operation modes in
background investigation and suppression techniques. We compare magnetic field
measurements in the inner spectrometer volume during system commissioning with
corresponding simulations, which allows to verify the system's functionality in
fine-tuning the magnetic field configuration. This is of major importance for a
successful neutrino mass measurement at KATRIN.Comment: 32 pages, 16 figure
Background due to stored electrons following nuclear decays in the KATRIN spectrometers and its impact on the neutrino mass sensitivity
The KATRIN experiment is designed to measure the absolute neutrino mass scale
with a sensitivity of 200 meV at 90% C.L. by high resolution tritium
beta-spectroscopy. A low background level of 10 mHz at the beta-decay endpoint
is required in order to achieve the design sensitivity. In this paper we
discuss a novel background source arising from magnetically trapped keV
electrons in electrostatic retarding spectrometers. The main sources of these
electrons are alpha-decays of the radon isotopes (219,220)Rn as well as
beta-decays of tritium in the volume of the spectrometers. We characterize the
expected background signal by extensive MC simulations and investigate the
impact on the KATRIN neutrino mass sensitivity. From these results we refine
design parameters for the spectrometer vacuum system and propose active
background reduction methods to meet the stringent design limits for the
overall background rate
Stochastic Heating by ECR as a Novel Means of Background Reduction in the KATRIN Spectrometers
The primary objective of the KATRIN experiment is to probe the absolute
neutrino mass scale with a sensitivity of 200 meV (90% C.L.) by precision
spectroscopy of tritium beta-decay. To achieve this, a low background of the
order of 10^(-2) cps in the region of the tritium beta-decay endpoint is
required. Measurements with an electrostatic retarding spectrometer have
revealed that electrons, arising from nuclear decays in the volume of the
spectrometer, are stored over long time periods and thereby act as a major
source of background exceeding this limit. In this paper we present a novel
active background reduction method based on stochastic heating of stored
electrons by the well-known process of electron cyclotron resonance (ECR). A
successful proof-of-principle of the ECR technique was demonstrated in test
measurements at the KATRIN pre-spectrometer, yielding a large reduction of the
background rate. In addition, we have carried out extensive Monte Carlo
simulations to reveal the potential of the ECR technique to remove all trapped
electrons within negligible loss of measurement time in the main spectrometer.
This would allow the KATRIN experiment attaining its full physics potential
Replacement of Contentious Inputs in Organic Farming Systems (RELACS) – a comprehensive Horizon 2020 project
Organic farmers adhere to high standards in producing quality food while protecting the environment. However, organic farming needs to improve continuously to keep meeting its ambitious objectives. The project ‘Replacement of Contentious Inputs in Organic Farming Systems’ (RELACS) will foster the development and adoption of cost-efficient and environmentally safe tools and technologies to further reduce the use of external inputs on organic farms across Europe as well as in Non EU Mediterranean countries.
Project partners will provide scientific support to develop fair and implementable EU rules to improve current practices in organic farming. Farm advisory networks in 11 European countries will reach out to farmers to ensure effective dissemination and adoption of the tools and techniques
Commissioning of the vacuum system of the KATRIN Main Spectrometer
The KATRIN experiment will probe the neutrino mass by measuring the
beta-electron energy spectrum near the endpoint of tritium beta-decay. An
integral energy analysis will be performed by an electro-static spectrometer
(Main Spectrometer), an ultra-high vacuum vessel with a length of 23.2 m, a
volume of 1240 m^3, and a complex inner electrode system with about 120000
individual parts. The strong magnetic field that guides the beta-electrons is
provided by super-conducting solenoids at both ends of the spectrometer. Its
influence on turbo-molecular pumps and vacuum gauges had to be considered. A
system consisting of 6 turbo-molecular pumps and 3 km of non-evaporable getter
strips has been deployed and was tested during the commissioning of the
spectrometer. In this paper the configuration, the commissioning with bake-out
at 300{\deg}C, and the performance of this system are presented in detail. The
vacuum system has to maintain a pressure in the 10^{-11} mbar range. It is
demonstrated that the performance of the system is already close to these
stringent functional requirements for the KATRIN experiment, which will start
at the end of 2016.Comment: submitted for publication in JINST, 39 pages, 15 figure
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