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Complete diets for laying hens are usually offered in meal form. This form initially promotes the laying hens’ natural feed intake behavior and allows them to satisfy their pecking behavior. At the same time, it can also cause difficulties, because it consists of different particles and is not a homogeneous unit. A homogeneous mixture is essential to ensure that each laying hen in the flock can meet its nutritional needs. If feed exhibits a wide particle size distribution, this can promote feed segregation during transport and selective feed intake behavior of laying hens. These two processes sometimes lead to significant differences between the composition of the feed produced and the composition of the feed that is finally ingested by the laying hens. Multi-stage sampling can be used to investigate progressing differences in feed composition. In this study, samples of different complete diets for laying hens (n = 76) were collected from ten organic farms in Germany to examine their particle size distributions (dry sieve analysis). Samples were taken at four different locations (V1 = loading, V2 = silo, V3 = at the beginning of the feed chain, V4 = at the end of the feed chain) in each farm. There was a tendency for V1 and V2 to be characterized by high proportions of particles between 1400 and 3150 µm (V1 = 61.2%, V2 = 43.5%). V3 and V4 consisted mainly of particles of size 500–800 µm and 200–400 µm, respectively. The lowest proportions across all variants were in the range above 3150 µm (V1 = 2.20%, V2 = 1.30%, V3 = 1.00%, V4 = 0.400%) and between 400 and 500 µm (V1 = 2.50%, V2 = 4.50%, V3 = 5.70%, V4 = 6.60%). The mean value comparison of the proportions of sieve mesh sizes from 200 to 1000 µm resulted in: V1 < V2 < V3 < V4; and of sieve mesh sizes between 1400 and 2000 µm in: V1 > V2 > V3 > V4. This observation can be explained by segregation of the feed during transport and a selective feeding behavior of the laying hens. However, trends were discontinuous and varied between the farms. Deviations from the guideline values were found in particular for particle sizes in the range of 1000 to 1400 µm.
25-hydroxycholecalciferol (25-OHD3) formed via hepatic hydroxylation from vitamin D, cholecalciferol, represents the precursor of the biologically active vitamin D hormone, 1,25-dihydroxyvitamin D. Due to a higher absorption rate and the omission of one hydroxylation, dietary supplementation of 25-OHD3 instead of vitamin D3 is considered to be more efficient as plasma concentrations of 25-OHD3 are increased more pronounced. The present review summarises studies investigating potential beneficial effects on mineral homeostasis, bone metabolism, health status and performance in sows, piglets and fattening pigs. Results are inconsistent. While most studies could not demonstrate any or only a slight impact of partial or total replacement of vitamin D3 by 25-OHD3, some experiments indicated that 25-OHD3 might alter physiological processes when animals are challenged, for example, by a restricted mineral supply.
To investigate the influence of two dietary sources of vitamin D on the vitamin D status, bone metabolism, welfare and birth progress of gestating and lactating sows, forty-nine multiparous sows were randomly assigned to one of two diets: “CON” (n = 25; 50 μg vitamin D3/kg feed) and “HYD” (n = 24; 50 μg 25-hydroxycholecalciferol/kg feed). The basal diets were protein- and phosphorus-reduced. The trial started on day 3 ante insemination of the sows and ended with weaning of the piglets on day 28 postpartum. Dietary supplementation of 25-hydroxycholecalciferol resulted in improved maternal vitamin D status (p < 0.001), fewer gait changes (p < 0.01) and longer standing time after feeding (day 5 ante partum; p < 0.05) compared to vitamin D3. However, the bone markers CrossLaps and osteocalcin were not affected. Overall, the present results suggest that sows fed 25-hydroxycholecalciferol instead of vitamin D3 showed improved locomotion and stance strength. However, this outcome is probably not related to altered bone metabolism. The underlying mechanisms must be investigated in further studies.
Duckweeds can be potentially used in human and animal nutrition, biotechnology or wastewater treatment. To cultivate large quantities of a defined product quality, a standardized production process is needed. A small-scale, re-circulating indoor vertical farm (IVF) with artificial lighting and a nutrient control and dosing system was used for this purpose. The influence of different light intensities (50, 100 and 150 µmol m−2 s−1) and spectral distributions (red/blue ratios: 70/30, 50/50 and 30/70%) on relative growth rate (RGR), crude protein content (CPC), relative protein yield (RPY) and chlorophyll a of the duckweed species Lemna minor and Wolffiella hyalina were investigated. Increasing light intensity increased RGR (by 67% and 76%) and RPY (by 50% and 89%) and decreased chlorophyll a (by 27% and 32%) for L. minor and W. hyalina, respectively. The spectral distributions had no significant impact on any investigated parameter. Wolffiella hyalina achieved higher values in all investigated parameters compared to L. minor. This investigation proved the successful cultivation of duckweed in a small-scale, re-circulating IVF with artificial lighting.
Duckweeds are fast-growing and nutritious plants, which are gaining increased attention in different fields of application. Especially for animal nutrition, alternative protein sources are needed to substitute soybean meal. The current bottleneck is the standardized production of biomass, which yields stable quantities of a defined product quality. To solve this problem, an indoor vertical farm (IVF) for duckweed biomass production was developed. It consists of nine vertically stacked basins with a total production area of 25.5 m2. The nutrient solution, a modified N-medium, re-circulated within the IVF with a maximum flow rate of 10 L min−1. Nutrients were automatically added based on electrical conductivity. In contrast, ammonium was continuously supplied. A water temperature of 23 °C and a light intensity of 105 μmol m−2 s−1 with a photoperiod of 12:12 h were applied. During a 40-day production phase, a total of 35.6 kg of fresh duckweed biomass (equals 2.1 kg of dried product) was harvested from the IVF. On average, 0.9 kg day−1 of fresh biomass was produced. The dried product contained 32% crude protein (CP) and high levels of proteinogenic amino acids (e.g. lysine: 5.42 g, threonine: 3.85 g and leucine: 7.59 g/100 g CP). Biomass of this quality could be used as a protein feed alternative to soybean meal. The described IVF represents a modular model system for duckweed biomass production in a controlled environment and further innovations and upscaling processes.
Dieser Artikel befasst sich mit dem bundesweiten Niveau der Treibhausgas (THG)-Emissionen und des Ressourcenverbrauchs in der deutschen Gemeinschaftsverpflegung im Segment "Business" und deren Einsparpotenziale durch verschiedene Szenarien der ungestützten und gestützten Rezeptüberarbeitung. Unter "ungestützt" verstehen wir in dieser Arbeit die intuitive Optimierung von Rezepten durch die Mitarbeiter von Betrieben der Gemeinschaftsverpflegung. Die "unterstützten" Ansätze mussten dagegen bestimmte Zielvorgaben erfüllen, zum Beispiel der Deutschen Gesellschaft für Ernährung; engl. Deutschen Gesellschaft für Ernährung oder das nachhaltige Niveau. Konkret Konkret wird getestet, wie sich (A) eine ungestützte Rezeptüberarbeitung, (B) eine Rezeptüberarbeitung auf Basis von Ernährungsempfehlungen und (C) eine Rezeptüberarbeitung mit wissenschaftlicher Begleitung die Umweltauswirkungen eines Gerichtes beeinflussen. Als methodischer Rahmen diente eine Online-Befragung von Unternehmen der Gemeinschaftsverpflegung sowie eine Szenarioanalyse auf Menüebene und auf nationaler Ebene durchgeführt. Die Ergebnisse basieren zum einen auf empirischen Daten und zum anderen auf Hochrechnungen. Die Ergebnisse zeigen, dass die die bundesweite Umsetzung der Rezepturüberarbeitung nach wissenschaftlichen Vorgaben - wie konkrete Zielvorgaben für die THG Emissionen pro Portion - bis zu 44% des Ressourcenverbrauchs in der deutschen Betriebsgastronomie einsparen kann (das entspricht 3,4 Millionen Tonnen Ressourcen pro Jahr) und bis zu 40 % der THG-Emissionen (0,6 Millionen Tonnen THG-Emissionen pro Jahr) einsparen.
Die Verschwendung von Lebensmitteln im Haushalt wird durch eine komplexe Reihe von routinemäßigen Verhaltensweisen bestimmt, und eine Unterbrechung dieser Routinen könnte zu einer Verringerung dieser enormen Menge an Lebensmittelabfällen führen. In der vorliegenden Studie wird eine solche Unterbrechung der Haushaltsroutinen untersucht: die Essensbox.
Das Potenzial von Essensboxen zur Verringerung verschiedener Arten von Lebensmittelabfällen in Haushalten wird zum ersten Mal in verschiedenen Ländern untersucht. Nachdem wir einen Rahmen für den Vergleich der Auswirkungen verschiedener Mahlzeitentypen auf die Lebensmittelverschwendung geschaffen haben, untersuchen wir anschließend die Auswirkungen einer abonnementbasierten Lebensmittelversorgung (d. h. Mahlzeitendosen) auf die gesamte Lebensmittelverschwendung sowie auf die verschiedenen Arten der Lebensmittelverschwendung: Zubereitung, Kochen und Tellerabfälle. Unser Datensatz enthält 8747 Beobachtungen von Mahlzeiten aus 955 Haushalten in sechs Ländern. Die Ergebnisse eines Bayes'schen Mehrebenen-Hurdle-Lognormal-Modells mit zufälligem Intercept zeigen, dass Essensboxen im Vergleich zu traditionell gekochten Mahlzeiten insgesamt zu einer Verringerung der gesamten Essensabfälle führen (38 % weniger). Mahlzeitendosen verringern vor allem das Auftreten und die Menge der verschwendeten Pfannen- und Topfgerichte (d. h. Kochabfälle) sowie die Menge der Mahlzeitenzubereitungsabfälle, führen jedoch im Vergleich zu herkömmlichen Mahlzeiten zu einem höheren Aufkommen von Zubereitungs- und Tellerabfällen. Dies zeigt, wie sich die Unterschiede zwischen den einzelnen Mahlzeiten auf die Lebensmittelabfälle in den Haushalten auswirken, ein Aspekt, der bisher in der Forschung wenig Beachtung gefunden hat. Während sich die meisten früheren Untersuchungen auf die gesamte Lebensmittelverschwendung in Haushalten konzentrierten, zeigt unsere Studie, dass die Unterscheidung zwischen verschiedenen Arten von Lebensmittelabfällen in Haushalten wichtige neue Erkenntnisse liefern kann.
Information systems (IS) play a central role in promoting corporate sustainability and pro-environmental behavior. This study explores the use of mobile apps for fostering sustainability-oriented corporate culture. It accentuates issues relating to sustainability-oriented corporate culture (RQ1), app meta-requirements as a strategic approach to addressing these issues (RQ2), as well as design and implementation principles (RQ3). Referring to the literature on sustainability apps, gamification, and nudging, our qualitative research design combines an analysis of four corporate apps intending to promote sustainable behavior and expert interviews (Grounded Theory). The proposed framework supports the planning, realization, and monitoring of this targeted app use. Single cultural dimensions inform seven issues in culture development. Five meta-requirements address this multi-dimensionality, challenges provided by new digital working environments, and principles of Green IT. Four design principles support, extend, and integrate current knowledge on app features, nudging, and gamification. Five variables determine the app intervention and maturity level. We conclude that this targeted app use should intend to foster the sustainability orientation within all dimensions of corporate culture instead of being limited to promoting sustainable behavior.
Oleamide is used as a lubricant in the manufacturing and application of polypropylene (PP) medical devices. Samples of PP were prepared with 0, 1500, and 15 000 ppm oleamide content as lubricant. The samples were either left non-sterile, sterilized with ethylene oxide (ETO), γ-radiation (γ) or autoclaved (A) and stored for up to 4 weeks. To determine the oleamide bulk-to-surface distribution depending on sterilization method and storage time an extraction method and a washing technique were applied. The oleamide content was determined by gas chromatography (GC-FID) and compared with the coefficient of friction (COF). The COF dependent on the measured lubricant content at the surface. The content of lubricant on the surface depends on the type of sterilization: ETO increased the lubricant content to some extent, γ-sterilization and autoclaving reduced it. After storage, no migration of the lubricant to the surface could be detected.
Flexibility in planning through frequent amendments. The practice of land use planning in Germany
(2022)
How can formal planning deal with uncertainty and rapid change while maintaining high standards of procedural certainty? This paper, using Germany as an example, examines how municipalities handle this dilemma within their existing planning systems. Municipalities use different approaches, ranging from regular redrafting to comprehensive changes or regular amendments. Amendments and complementary informal plans are important components of flexibility in planning. We argue that the choice to make frequent amendments instead of redrafting the preparatory land-use plan does not necessarily lead to a loss of a city-wide, long-term perspective, provided amendments are prepared and justified using informal concepts.