Buchweizen: ein Futtermittel für Legehennen?

Buckwheat (Fagopyrum esculentum) has a high ecological value due to the long and intensive flowering as well as its favorable impact on soil fertility. In addition, as a typical catch crop, it provides the possibility of a second harvest on arable land in moderate European regions. However, in Europe demand for buckwheat kernels as food is low. Therefore, the question arises whether cultivation of this plant could be promoted by using it as animal feed. In the current experiment, the extent to which buckwheat is consumed by laying hens was tested in conjunction with potential effects on egg yield and quality. Three groups of laying hens (n=13 per group) were fed a layer diet containing either 40% wheat, 40% hulled buckwheat or 40% crude buckwheat. Feeds were offered ad libitum in form of groats. Feed intake was measured and eggs were sampled before and during the experiment. Feed intake was significantly increased with crude buckwheat, as also were egg weights. Egg number was not affected. The weight and stability of the eggshell were significantly higher with crude buckwheat. The color of the yolk was slightly altered with hulled buckwheat. The results demonstrate that buckwheat is an interesting option as an ecologically and economically valuable feed source for layers, which at least does not cause negative impacts on feed intake and egg yield, compared to wheat

Effects of species-diverse high-alpine forage on in vitro ruminal fermentation when used as donor cow's feed or directly incubated

Alpine forages are assumed to have specific effects on ruminal digestion when fed to cattle. These effects were investigated in an experiment from two perspectives, either by using such forages as a substrate for incubation or as feed for a rumen fluid donor cow. In total, six 24-h in vitro batch culture runs were performed. Rumen fluid was collected from a non-lactating donor cow after having grazed pastures at ∼2000 m above sea level for 2, 6 and 10 weeks. These ‘alpine runs' were compared with three lowland samplings from before and 2 and 6 weeks after the alpine grazing where a silage-concentrate mix was fed. In each run, nine replicates of four forages each were incubated. These forages differed in type and origin (alpine hay, lowland ryegrass hay, grass-maize silage mix, pure hemicellulose) as well as in the content of nutrients. Concentrations of phenolic compounds in the incubated forages were (g/kg dry matter (DM)): 20 (tannin proportion: 0.47), 8 (0.27), 15 (0.52) and 0 (0), respectively. Crude protein was highest in the silage mix and lowest with hemicellulose, whereas the opposite was the case for fiber. The total phenol contents (g/kg DM) for the high altitude and the lowland diet of the donor cow were 27 (tannins: 0.50 of phenols) and 12 (0.27), respectively. Independent of the origin of the rumen fluid, the incubation with alpine hay decreased (P < 0.05) bacterial counts, fermentation gas amount, volatile fatty acid (VFA) production as well as ammonia and methane concentrations in fermentation gas (the latter two being not lower when compared with hemicellulose). Alpine grazing of the cow in turn increased (P < 0.001) bacterial counts and, to a lesser extent, acetate proportion compared with lowland feeding. Further, alpine grazing decreased protozoal count (P < 0.05) and VFA production (P < 0.001) to a small extent, whereas methane remained widely unchanged. There were interactions (P < 0.05) between forage type incubated and feeding period of the donor cow in protozoal counts, acetate:propionate ratio, fermentation gas production and its content of methane, in vitro organic matter digestibility and metabolizable energy. Although increased phenolic compounds were the most consistent common property of the applied alpine forages, a clear attribution to certain effects was not possible in this study. As a further result, adaptation (long-term for donor cow, short term for 24 h incubations) appears to influence the expression of alpine forage effects in ruminal fermentatio

Transfer of linoleic and linolenic acid from feed to milk in cows fed isoenergetic diets differing in proportion and origin of concentrates and roughages

The transfer of ingested α-linolenic acid (ALA) and linoleic acid (LA) determines the nutritional quality of milk, but the factors determining this transfer are unclear. The present experiment investigated the influence of roughage to concentrate proportions and the effect of concentrate types on milk fat composition. Respectively, six lactating dairy cows were fed one of three isoenergetic (5·4±0·05 MJ net energy for lactation/kg dry matter; DM) and isonitrogenous (215±3·5 g crude protein/kg DM) diets, consisting of ryegrass hay only (33 g fatty acids/kg DM; ALA-rich, no concentrate), maize (straw, whole maize pellets and gluten; 36 g fatty acids/kg DM; LA-rich; 560 g concentrate/kg DM), or barley (straw and grain plus soybean meal; 19 g fatty acids/kg DM; LA-rich; 540 g concentrate/kg DM). The fatty acid composition of feeds and resulting milk fat were determined by gas chromatography. The ALA concentration in milk fat was highest (P<0·001) with the hay-diet, but the proportionate transfer of ALA from diet to milk was lower (P<0·001) than with the maize- or barley-diets. The LA concentration in milk fat was highest with the maize-diet (P<0·05, compared with hay) but relative transfer rate was lower (P=0·01). The transfer rates of ALA and LA were reciprocal to the intake of individual fatty acids which thus contributed more to milk fat composition than did roughage to concentrate proportions. The amount of trans-11 18:1 in milk fat was lowest with the barley-diet (P<0·001) and depended on the sum of ALA and LA consumed. The milk fat concentration of cis-9, trans-11 18:2 (rumenic acid) was more effectively promoted by increasing dietary LA (maize) than ALA (hay). Amounts of 18:0 secreted in milk were four (maize) to seven (hay) times higher than the amounts ingested. This was suggestive of a partial inhibition of biohydrogenation in the maize-diet, possibly caused by the high dietary LA leve

Was tun im Niedriglohnbereich? Eine kritische Auseinandersetzung mit einem neueren Kombilohnkonzept

Das von einer Forschergruppe um Prof. Dr. Peter Bofinger entwickelte Kombilohnmodell bessert die Situation auf dem Arbeitsmarkt kaum. Würde es umgesetzt, entstünden nur wenige neue Arbeitsplätze, während viele Geringverdiener Einbußen erleiden würden. Zu diesem Ergebnis kommt eine Analyse des Instituts für Makroökonomie und Konjunkturforschung (IMK) und des Wirtschafts- und Sozialwissenschaftlichen Instituts (WSI). Die beiden Forschungsinstitute in der Hans-Böckler-Stiftung unterstützen aber den Bofinger-Ansatz, die Subventionen für Minijobs abzuschaffen, weil so die Verdrängung regulärer Beschäftigung gestoppt werden könne. Zudem empfehlen IMK und WSI einen existenzsichernden Mindestlohn und auf begrenzte Zielgruppen zugeschnittene Lohnzuschüsse als sinnvolle Komponenten für eine Reform des Niedriglohnsektors.In Germany the discussion about wage subsidies continues. Most recently it has concentrated on a model developed by a research team of Professor Bofinger and other economists, who suggest that the employee's share of the social security contributions should be subsidised via a negative income tax for low-paid employees, whose weekly working time exceeds a defined minimum. This is combined with a minimum wage of 4.50 euros. If this concept were applied, it would create only a limited number of new jobs, while the income of a large number of low-paid employees would decline. This is the result of an analysis by the Institute of Social and Economic Research (WSI) and the Macroeconomic Policy Institute (IMK). However, both research institutes of the Hans-Boeckler-Foundation support Professor Bofinger's proposal to abolish subsidies for marginal employment (so-called "Minijobs" of up to 400 euros per month). At the same time the WSI and the IMK recommend the introduction of a minimum wage that ensures a decent living. This should be much higher than the proposed 4.50 euros. For limited time periods and special target groups wage subsidies might make sense as an additional measure

Temporally Asymmetric Fluctuations are Sufficient for the Operation of a Correlation Ratchet

It has been shown that the combination of a broken spatial symmetry in the potential (or ratchet potential) and time correlations in the driving are crucial, and enough to allow transformation of the fluctuations into work. The required broken spatial symmetry implies a specific molecular arrangement of the proteins involved. Here we show that a broken spatial symmetry is not required, and that temporally asymmetric fluctuations (with mean zero) can be used to do work, even when the ratchet potential is completely symmetric. Temporal asymmetry, defined as a lack of invariance of the statistical properties under the operation to temporal inversion, is a generic property of nonequilibrium fluctuation, and should therefore be expected to be quite common in biological systems.Comment: 17 pages, ps figures on request, LaTeX Article Forma

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 $\beta$-decay spectrum close to its endpoint with a spectrometer based on the MAC-E filter technique. The $\beta$-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

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