Institut für Tropische Agrarwissenschaften (Hans-Ruthenberg-Institut)

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Relationship between nutritional composition and fibre digestibility in tropical forages compared to temperate forages
(2024) Nurdianti, Risma Rizkia; Dickhöfer, Uta; Castro-Montoya, Joaquín Miguel
The study aimed to analyse variability in nutrient concentration and fibre digestibility in forage legumes and grasses from tropical and temperate regions and identify forage species with similar fibre concentration and digestibility. Forty-five samples comprised 22 tropical forage legumes, four temperate forage legumes, eleven tropical grasses, and eight temperate grasses were analysed for their proximate nutritional composition, as well as fibre digestibility by 240-h of in vitro incubation in buffered rumen fluid. All data were analysed using SAS (SAS Institute Inc., USA). Pearson correlations and multiple linear regressions were determined using CORR and GLM procedures, respectively. Cluster analyses were done using CLUSTER procedures. Tropical forage legumes had greater ash-corrected neutral detergent fibre (aNDFom) concentrations compared to temperate forage legumes, but lower aNDFom concentrations compared to tropical and temperate grasses. Tropical forage legumes had greater undigested neutral detergent fibre estimated after 240 h in vitro incubation (uNDF240) concentrations compared to other forages. In tropical forage legumes, aNDFom and lignin concentrations correlated with uNDF240 concentration (p < 0.001). Meanwhile, there were no relationships between explanatory variables and fibre digestibility (p > 0.100). Four clusters of forage species varying in fibre concentration and fibre digestibility were identified. Peanut, lima bean, and cowpea forages might have low fibre concentration and medium fibre digestibility similar to those of alfalfa and red clover. Despite differences in environmental conditions, tropical forage legumes might compete with temperate species in terms of nutrient and fibre quality. This information allows tropical farmers to improve forage quality by choosing appropriate species.
Metabolome fingerprinting reveals the presence of multiple nitrification inhibitors in biomass and root exudates of Thinopyrum intermedium
(2024) Issifu, Sulemana; Acharya, Prashamsha; Schöne, Jochen; Kaur-Bhambra, Jasmeet; Gubry-Rangin, Cecile; Rasche, Frank
Biological Nitrification Inhibition (BNI) encompasses primarily NH4 +-induced release of secondary metabolites to impede the rhizospheric nitrifying microbes from per- forming nitrification. The intermediate wheatgrass Thinopyrum intermedium (Kernza®) is known for exuding several nitrification inhibition traits, but its BNI potential has not yet been identified. We hypothesized Kernza® to evince BNI potential through the presence and release of multiple BNI metabolites. The presence of BNI metabolites in the biomass of Kernza® and annual winter wheat (Triticum aestivum) and in the root exudates of hydroponically grown Kernza®, were fingerprinted using HPLC-DAD and GC–MS/MS analyses. Growth bioassays involving ammonia-oxidizing bacteria (AOB) and archaea (AOA) strains were conducted to assess the influence of the crude root metabolome of Kernza® and selected metabolites on nitrification. In most instances, significant concentrations of various metabolites with BNI potential were observed in the leaf and root biomass of Kernza® compared to annual winter wheat. Furthermore, NH4 + nutrition triggered the exudation of various phenolic BNI metabolites. Crude root exudates of Kernza® inhibited multiple AOB strains and completely inhibited N. viennensis. Vanillic acid, caffeic acid, vanillin, and phenylalanine suppressed the growth of all AOB and AOA strains tested, and reduced soil nitrification, while syringic acid and 2,6-dihydroxybenzoic acid were ineffective. We demonstrated the considerable role of the Kernza® metabolome in suppressing nitrification through active exudation of multiple nitrification inhibitors.
Biomonitoring via DNA metabarcoding and light microscopy of bee pollen in rainforest transformation landscapes of Sumatra
(2022) Carneiro de Melo Moura, Carina; Setyaningsih, Christina A.; Li, Kevin; Merk, Miryam Sarah; Schulze, Sonja; Raffiudin, Rika; Grass, Ingo; Behling, Hermann; Tscharntke, Teja; Westphal, Catrin; Gailing, Oliver; Carneiro de Melo Moura, Carina; Department of Forest Genetics and Forest Tree Breeding, University of Göttingen, Göttingen, Germany; Setyaningsih, Christina A.; Department of Palynology and Climate Dynamics, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Göttingen, Germany; Li, Kevin; Agroecology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany; Merk, Miryam Sarah; Statistics and Econometrics, University of Göttingen, Göttingen, Germany; Schulze, Sonja; Agroecology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany; Raffiudin, Rika; Department of Biology, IPB University ID, Bogor, Indonesia; Grass, Ingo; Department of Ecology of Tropical Agricultural Systems, University of Hohenheim, Stuttgart, Germany; Behling, Hermann; Department of Palynology and Climate Dynamics, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Göttingen, Germany; Tscharntke, Teja; Agroecology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany; Westphal, Catrin; Functional Agrobiodiversity, Department of Crop Sciences, University of Göttingen, Göttingen, Germany; Gailing, Oliver; Centre of Biodiversity and Sustainable Land Use, University of Göttingen, Göttingen, Germany
Background: Intense conversion of tropical forests into agricultural systems contributes to habitat loss and the decline of ecosystem functions. Plant-pollinator interactions buffer the process of forest fragmentation, ensuring gene flow across isolated patches of forests by pollen transfer. In this study, we identified the composition of pollen grains stored in pot-pollen of stingless bees, Tetragonula laeviceps , via dual-locus DNA metabarcoding (ITS2 and rbcL ) and light microscopy, and compared the taxonomic coverage of pollen sampled in distinct land-use systems categorized in four levels of management intensity (forest, shrub, rubber, and oil palm) for landscape characterization. Results: Plant composition differed significantly between DNA metabarcoding and light microscopy. The overlap in the plant families identified via light microscopy and DNA metabarcoding techniques was low and ranged from 22.6 to 27.8%. Taxonomic assignments showed a dominance of pollen from bee-pollinated plants, including oil-bearing crops such as the introduced species Elaeis guineensis (Arecaceae) as one of the predominant taxa in the pollen samples across all four land-use types. Native plant families Moraceae, Euphorbiaceae, and Cannabaceae appeared in high proportion in the analyzed pollen material. One-way ANOVA (p > 0.05), PERMANOVA (R² values range from 0.14003 to 0.17684, for all tests p-value > 0.5), and NMDS (stress values ranging from 0.1515 to 0.1859) indicated a lack of differentiation between the species composition and diversity of pollen type in the four distinct land-use types, supporting the influx of pollen from adjacent areas. Conclusions: Stingless bees collected pollen from a variety of agricultural crops, weeds, and wild plants. Plant composition detected at the family level from the pollen samples likely reflects the plant composition at the landscape level rather than the plot level. In our study, the plant diversity in pollen from colonies installed in land-use systems with distinct levels of forest transformation was highly homogeneous, reflecting a large influx of pollen transported by stingless bees through distinct land-use types. Dual-locus approach applied in metabarcoding studies and visual pollen identification showed great differences in the detection of the plant community, therefore a combination of both methods is recommended for performing biodiversity assessments via pollen identification.
Insect conservation in agricultural landscapes needs both high crop heterogeneity and semi-natural habitats
(2024) Tassoni, Sara; Becker, David; Kasten, Marit Kinga; Moriníere, Jérôme; Grass, Ingo
Identifying landscapes that are suitable for both biodiversity conservation and agricultural production is a major challenge. Traditionally, much research has focused on biodiversity conservation outside of agricultural production areas, e.g., in semi-natural habitats. In contrast, recent research has mainly focused on the potential of crop heterogeneity. This includes both compositional (crop diversity) and configurational heterogeneity (field border density). However, if and how crop heterogeneity, and semi-natural habitats interact to shape insect diversity in agricultural landscapes remains poorly understood. Here we investigated the combined effects of crop diversity, field border density, and semi-natural habitats (i.e., grassland proportion, hedge density) on insect diversity. We sampled insect communities from 14 – 17 June 2021 with pan traps in 27 study landscapes (500 m x 500 m) covering independent gradients of these landscape variables and identified a total of 587 insect species with DNA metabarcoding. We found that field border density mediated the effects of crop diversity, grassland proportion, and hedge density on insect richness. At low levels of field border density (i.e., landscapes with mostly large fields), effects were either neutral (crop diversity), negative (grassland proportion) or weakly positive (hedge density). By contrast, at high levels of field border density, crop diversity, grassland proportion, and hedge density all exerted positive effects on insect richness. Responses to crop heterogeneity and semi-natural habitat differed among trophic groups of insects (decomposers, herbivores, parasitoids, predators). While variation in richness of herbivorous insects followed the patterns of the overall richness, decomposer richness was not related to any of the investigated variables. Predator richness increased with hedge density in landscapes, whereas parasitoid richness increased when high levels of field border density and grassland proportion coincided. Our study shows that increasing crop heterogeneity is a viable strategy for promoting insect diversity in agricultural landscapes. However, the effects of the amount of remaining semi-natural habitats, such as grassland or hedges, are mediated by configurational heterogeneity, and vary between trophic groups. Efforts to conserve insects in agricultural landscapes must therefore focus on both increasing the heterogeneity of the crop matrix by promoting crop diversity and increasing the density of field borders, while also maintaining or restoring semi-natural habitats as important source habitats for insect species.
The adoption potential of extended lactation as a strategy to reduce excess calf numbers in dairy farming
(2024) Gresham, Josephine; Reiber, Christoph; Chagunda, Mizeck G. G.
Dairy production relies predominantly on a few, selectively bred, high-yielding dairy breeds, resulting in a surplus of low-value male offspring. This situation leads to a conflict between a growing demand for milk and low appreciation for dairy calves. Extending lactation could reduce the number of calves born. This study aimed to assess the current use of extended lactation in dairy production in Southern Germany, identify the perceived potential, and determine the biological potential extended lactation has to reduce calf numbers. A survey from 2020 with 310 farmers was analysed. A total of 145 (46.8%) farmers used extended lactation. The use of extended lactation on farms correlated significantly with breed, milk yield, interest in continuing or implementing the use of extended lactation, and the indicated feasibility of extended lactation. The perceived potential was assessed by 39.8% of farmers as “high” to “very high”. A total of 17 (12.8%) farmers currently not using extended lactation were identified as potential adopters. Together with existing adopters, this could result in 52.3% of farms using extended lactation, which could biologically reduce calf numbers by 7.3% or 14.1% p.a., when extended by three or six months, respectively. This adoption potential shows that extended lactation can reduce calf numbers considerably, addressing both ethical and economic concerns in dairy farming and benefiting farmers as well as society.
Leaf gas exchange of lowland rice in response to nitrogen source and vapor pressure deficit
(2021) Vu, Duy Hoang; Stürz, Sabine; Pieters, Alejandro; Asch, Folkard
Background: In anaerobic lowland fields, ammonium (NH4+) is the dominant form of nitrogen (N) taken up by rice plants, however, with the large expansion of water-saving irrigation practices, nitrification is favored during drained periods, leading to an increased availability of nitrate (NO3−). Aim: Since the uptake and assimilation of the two N-sources differ in their demand of pho- tosynthates, leaf gas exchange may be subject to adjustments in response to N-sources, particularly at high evaporative demand, when stomatal conductance (gs ) is very sensitive. Methods: Three experiments were carried out to study leaf gas exchange of various low- land rice varieties in response to N-source at low and high vapor pressure deficit (VPD). In the first experiment, seedlings of 12 rice varieties were grown at high VPD for 3 weeks. From this, four rice varieties differing in gs and CO2 assimilation rate (A) were selected and grown for 2 weeks at low VPD, and after that, they were shifted to high VPD for 1 week, whereas in the third experiment, the same varieties were grown separately at low and high VPD conditions for 2 weeks. In all three experiments, plants were grown hydroponi- cally in nutrient solution with N-sources as sole NH4+ or NO3−. Results: At high VPD, NO3− nutrition led to a higher gs and A in four out of 12 vari- eties (IR64, BT7, NU838, and Nipponbare) relative to NH4+ nutrition, while no effect was observed at low VPD or after a short-term exposure to high VPD. Further, varieties with a high intrinsic water-use efficiency (WUEi; IR64 and BT7) showed the strongest response to N-source. Higher gs was partially supported by increased root/shoot ratio, but could not be fully explained by the measured parameters. However, higher A in NO3−-fed plants did not always result in increased plant dry matter, which is probably related to the higher energy demand for NO3− assimilation. Our results suggest that at high VPD, NO3− nutri- tion can improve leaf gas exchange in varieties having a high WUEi, provided a sufficient water supply. Conclusion: Therefore, intensified nitrification under water-saving irrigation measures may improve leaf gas exchange and the growth of rice plants under high transpirational demand. However, choice of variety seems crucial since large varietal differences were observed in response to N-source. Further, breeding strategies for genotypes adapted to aerobic soil conditions should consider responses to NO3−, potentially using gas exchange measurements as a screening tool.
Spent Pleurotus ostreatus substrate has potential for managing Fusarium wilt of banana
(2021) Ocimati, Walter; Were, Evans; Tazuba, Anthony Fredrick; Dita, Miguel; Zheng, Si-Jun; Blomme, Guy
A range of basidiomycetes including the edible mushroom Pleurotus ostreatus (Po) can suppress plant pathogens such as Fusarium spp. With the current increase in production and consumption of Po in Uganda, the spent Po substrate (SPoS) could be an alternative to manage Fusarium wilt of banana (FWB), caused by the soil borne pathogen Fusarium oxysporum f. sp. cubense, race 1 (Foc). This study determined the potential of SPoS to inhibit Foc in vitro and in potted plants. In vitro studies confirmed suppression of Foc in pure co-culture (Po vs. Foc) assays and media amended with different concentrations (0% to 50% w/v) of un-sterilized SPoS filtrates. Foc growth in the sterile SPoS filtrate was comparable to the water control, suggesting possible roles of biotic or thermolabile components of the SPoS. To further verify the suppressive effects of SPoS, pot experiments were carried out with a resistant (‘Mbwazirume’, AAA) and susceptible (‘Sukali Ndizi’, AAB) banana cultivar using both artificially and naturally infested soils. Independent of the inoculation method, SPoS significantly reduced the severity of FWB in pot experiments. Susceptible cultivar ‘Sukali Ndizi’ growing in substrates amended with SPoS showed lower (1.25) corm damage (Scale 0–5) than the un-amended control (3.75). No corm damage was observed in uninoculated controls. The resistant cultivar ‘Mbwazirume’, showed slight (0.25) corm damage only in the Foc-inoculated plants without SPoS. These findings suggest that SPoS could be used as part of the management practices to reduce the impact of FWB.
Land use land/cover change reduces woody plant diversity and carbon stocks in a lowland coastal forest ecosystem, Tanzania
(2022) Ntukey, Lucas Theodori; Munishi, Linus Kasian; Treydte, Anna Christina
The East-African lowland coastal forest (LCF) is one of Africa’s centres of species endemism, representing an important biodiversity hotspot. However, deforestation and forest degradation due to the high demand for fuelwood has reduced forest cover and diversity, with unknown consequences for associated terrestrial carbon stocks in this LCF system. Our study assessed spatio-temporal land use and land cover changes (LULC) in 1998, 2008, 2018 in the LCF ecosystem, Tanzania. In addition, we conducted a forest inventory survey and calculated associated carbon storage for this LCF ecosystem. Using methods of land use change evaluation plug-in in QGIS based on historical land use data, we modelled carbon stock trends post-2018 in associated LULC for the future 30 years. We found that agriculture and grassland combined increased substantially by 21.5% between the year 1998 and 2018 while forest cover declined by 29%. Furthermore, forest above-ground live biomass carbon (AGC) was 2.4 times higher in forest than in the bushland, 5.8 times in the agriculture with scattered settlement and 14.8 times higher than in the grassland. The estimated average soil organic carbon (SOC) was 76.03 ± 6.26 t/ha across the entire study area. Our study helps to identify land use impacts on ecosystem services, supporting decision-makers in future land-use planning.
Do biotic and abiotic factors influence the prevalence of a common parasite of the invasive alien ladybird Harmonia axyridis?
(2022) Haelewaters, Danny; Hiller, Thomas; Ceryngier, Piotr; Eschen, René; Gorczak, Michał; Houston, Makenna L.; Kisło, Kamil; Knapp, Michal; Landeka, Nediljko; Pfliegler, Walter P.; Zach, Peter; Aime, M. Catherine; Nedvěd, Oldřich
Hesperomyces virescens (Ascomycota, Laboulbeniales), a fungal ectoparasite, is thus far reported on Harmonia axyridis from five continents: North and South America, Europe, Africa, and Asia. While it is known that He. virescens can cause mortality of Ha. axyridis under laboratory conditions, the role of biotic and abiotic factors in influencing the distribution of He. virescens in the field is unknown. We collected and screened 3,568 adult Ha. axyridis from 23 locations in seven countries in Central Europe between October and November 2018 to test the effect of selected host characters and climate and landscape variables on the infection probability with He. virescens. Mean parasite prevalence of He. virescens on Ha. axyridis was 17.9%, ranging among samples from 0 to 46.4%. Host sex, climate, and landscape composition did not have any significant effect on the infection probability of He. virescens on Ha. axyridis. Two color forms, f. conspicua and f. spectabilis, had a significantly lower parasite prevalence compared to the common Ha. axyridis f. novemdecimsignata.
Changing conditions for local food actors to operate towards agroecology during the COVID-19 pandemic
(2022) Frank, Markus; Kaufmann, Brigitte; Ejarque, Mercedes; Lamaison, María Guadalupe; Nessi, María Virginia; Amoroso, Mariano Martin
Given the novel character of disturbances caused by the pandemic in food systems, initial studies have been conducted to stress the reinforced urgent need for food systems' transformation toward sustainability. First assessments, conducted in the early months of the pandemic, found that local food actors responded to changing production and marketing conditions by implementing alternative practices under the umbrella of agroecology. However, given the unprecedented and dynamic character of the pandemic in regional situations, and related context-specific changes caused in food system actors' operations, case studies are needed to assess in more detail under which changing conditions food actors implemented alternative practices. Moreover, the maintenance of practices as conditions normalize, and food actors' transformative potential in relation to the principles of agroecology, need further assessment. In response to these emerging issues, we provide insights into our case study research conducted during 2021 in a local food system in Argentina. The aim of this research was to study how changing conditions triggered local food actors to (re-)frame their objectives and activities regarding marketing, and to assess the relevance of agroecological principles as a means of responding to changing conditions and to unfold longer-term transitions. We identified local producer shops (n = 5) and markets (n = 4) that were established or consolidated by self-organized producer groups (SOPGs) during the first months of the pandemic. Using semi-structured interviews with SOPG members (n = 12) and qualitative content analysis, we found that alternative practices were adopted in response to different changing conditions, and new needs and opportunities for producers and consumers brought about by the pandemic. Objectives pursued, and activities undertaken by the groups revealed reactive short-term mitigation strategies, and proactive longer-term transformative objectives. The relational analysis between practices and agroecological principles showed that the principles became important means of responding to changing conditions and to unfold longer-term transitions. The cases illustrate how local food actors operationalized agroecological principles, and in turn how principles can be used to investigate the nature and potentials of food actors' alternative practices, highlighting the relevance of agroecology to co-design sustainability transitions in local food systems and to mitigate possible future crisis.
Livestock, gender, food security and nutrition: A case study from Bangladesh
(2022) Fatema Sarker; Birner, Regina
Policymakers and development agencies increasingly adopt livestock interventions to enhance livelihood strategies and ensure the food and nutrition of poor people in the Global South to achieve the United Nations’ sustainable development goals (SDGs). Livestock interventions in many developing countries target women, given their crucial role in livestock production. While livestock interventions envision to benefit women by providing increased access to resources and higher incomes, there is a concern that programs tailored to women can jeopardize this objective due to increased work burden and women's time poverty. Moreover, while programs tailored to women promise to have a more positive effect on food and nutrition security than programs tailored to men, important knowledge gaps remain on how gender relations shape livestock production and how food security is achieved within the household. Knowledge on how animal-sourced food is allocated among the household members for better nutritional status has also not been fully uncovered. To address these knowledge gaps, this dissertation investigates the relationship between women's empowerment and food security and nutritional outcomes in livestock farming households. The thesis comprises an introduction, a chapter that presents a literature review, two chapters that present empirical findings and a final chapter that discusses the findings and develops conclusions. Following the introduction, the second chapter of this dissertation lays the foundation by providing a systematic literature review of the relationship between livestock interventions, women's empowerment, and food and nutrition security in developing countries. The third and fourth chapters focus on two livestock interventions in Bangladesh to further examine the influence of women's empowerment on household food security and nutrition and nutritional status of the household members. The reasons for selecting this South Asian country are the following: The country has a high population density and a high prevalence of malnutrition that is inconsistent with the country's recent economic development. Moreover, rural livelihoods are vulnerable due to decreased agricultural land per capita. From a gender perspective, the country offers interesting insights as it is characterized by a rigid patriarchal society. The country features large-scale livestock interventions, but limited knowledge is available on their effectiveness, especially with regard to gender and nutrition. Chapter 2 assesses the existing literature to analyze the current knowledge on how livestock interventions affect gender relations and food and nutrition in developing countries. Based on a systematic literature review of 27 studies following the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) framework, the findings suggest that livestock interventions have a considerable potential to empower women. Still, some unintended adverse effects arise, for instance, an increase in women's work burden. The review further indicates that women's empowerment in livestock farming tends to increase household food and nutrition security. Since a livestock intervention changes intrahousehold gender dynamics, a specific pathways assessment of all household members' food security and nutritional status is necessary. Many interventions and many research studies did not consider specific pathways by which livestock interventions and women’s empowerment may lead to improved food and nutrition security. Consequently, intended food and nutrition security outcomes could not be achieved. Similarly, the review suggests that in view of context-specific gender roles and liabilities in livestock farming, interventions that solely target women may jeopardize food security objectives. Therefore, the chapter concludes that researchers and development agencies that study or introduce livestock interventions should pay more attention to the types of animals to be promoted, the specific rearing requirements of different breeds or animal types, gender demands, the economic condition of the respective households, and socio-cultural norms. The third chapter of this dissertation seeks to assess how prevailing gender norms accelerate or impede the success of livestock interventions. The chapter is based on case studies in Bangladesh, which feature a qualitative analysis of the linkages between different livestock interventions, women empowerment, and food and nutrition security. The main data collection method were gendered focus group discussions, including participatory impact diagrams, involving 231 livestock farmers. The chapter reveals that women who manage small ruminants and low-yielding local cow breeds were more empowered and capable of addressing their household's food and nutritional needs than their peers with access to cross-bred livestock. Contrary to expectations, such women also had a higher bargaining power over intra-household expenditure than those managing large and improved ruminant breeds. The reason is that when households adopt cross-bred animals, men acquire more control over them than they have over local cows. The fourth chapter examines the intrahousehold allocation of animal-sourced food with quantitative data from 275 farm households and qualitative data from nine focus group discussions in rural Bangladesh. In households with a higher empowerment level of women, adolescent girls' animal-based protein food intake turned out to be less than that of adolescent boys. Empowered women were still found to have a lower protein food intake than their spouses. These inequal patterns of intrahousehold allocation of nutritious food nullify the development organizations' assumptions of more equal food and nutritional outcomes as an obvious consequence of women's empowerment in livestock keeping households. Thus, policies and interventions that aim to empower women in livestock for better food security and nutritional outcomes need to be based a deeper understanding the intrahousehold allocation of nutritious food. Overall, this dissertation confirms that women's empowerment in livestock farming matters for the rural population's household food security and nutritional outcomes in developing countries. However, the thesis also highlights the significance of understanding gender norms, roles and responsibilities concerning livestock farming and intra-household food allocation, before formulating any livestock interventions that aim to improve food security conditions, provide better livelihood options to eliminate poverty, or tackle other development issues. The thesis further points to the inequities in intrahousehold resource allocation behavior in the case of animal-sourced foods. The findings reaffirm the importance of considering gender relations and bargaining power in implementing development initiatives to improve household members' nutritional outcomes, especially that of female members of the household. The dissertation concludes that to release the maximum potential of livestock interventions to improve food security and nutrition, it is essential to empower women in livestock farming while avoiding unintended burdens and ensuring that the nutritional benefits of livestock reach all household members.
Einsatz digitaler Technologien in pferdehaltenden Betrieben zur Steigerung des Tierwohls und der Tiergesundheit
(2023) Pfeiffer, Melanie; Dickhöfer, Uta
Die Ansprüche der Pferde an ihre Lebensumstände haben sich trotz ihrer Domestikation kaum verändert und so ist das Wissen um ihre natürlichen Bedürfnisse, individu- eller Befindlichkeiten und Wünsche zur Ermöglichung eines artgemäßen Lebens, auch unter menschlicher Obhut, äußerst bedeutsam (Pick et al., 2016, S. 15). Das Verhalten der Pferde spiegelt den emotionalen Zustand eines Pferdes wider, werden Alarmsignale beobachtet, kann dies ein Zeichen dafür sein, dass die Anpassung an eine Haltungsumgebung nicht gelingt. In Folge dessen können chronischer Stress und Verhaltensstörungen entstehen. (Zeitler-Feicht, 2015, S. 30). Der Tagesablauf der Pferde unter heutigen Haltungsbedingungen weicht zum Teil stark vom natürlichen Zeitbudget der Pferde ab (Zeitler-Feicht, 2015, S. 30). Die Einhaltung des natürlichen Tageszeitbudgets ist Voraussetzung für ein ausgeglichenes Verhalten der Tiere, eine fehlende Bedürfnisbefriedigung kann sich vor allem aber auch auf den Verdauungs- und Bewegungsapparat der Tiere auswirken. (Zeitler-Feicht, 2015, S. 36; Pirkelmann et al., 2008, S. 28) Die Erfassung von Langzeitaktivitäten (Futteraufnahme-, Ruhe- und Bewegungsverhalten) dient zum einen der Überprüfung des Zeitbudgets der Pferde, zum anderen können sie auch als Indikatoren, die im Rahmen des § 11 Absatz 8 für Betriebsleitende zu erheben sind, dienen (Lemke, 2023, S. 16). Im Zuge dessen können vor allem digitale Technologien den Arbeitsalltag erleichtern, denn in großen Beständen ist die Überwachung tierbezogener Indikatoren sehr zeitaufwendig. (Stachowicz & Umstätter, 2021) Ein Mehrwert durch digitale Techniken in pferdehaltenden Betrieben entsteht des Weiteren durch die Möglichkeit der kontinuierlichen und objektiven Erfassung von Indikatoren sowie die Sicherstellung der Doku- mentation. Durch eine kontinuierliche Erfassung der Indikatoren können darüber hinaus auch Management-, Fütterungs- und Haltungssysteme verglichen und bewertet werden. (Stachowicz & Umstätter, 2021) Ziel der vorliegenden Arbeit war die Darstellung verschiedener Möglichkeiten für pferdehaltende Betriebe, digitale Technologien zur Sicherstellung des Tierwohls und der Tiergesundheit einzusetzen, um Langzeitaktivitäten wie die Nahrungssuche und -auf- nahme sowie das Ruhe- und Fortbewegungsverhalten von Pferden zu erfassen. Auf Grundlage der erfassten Indikatoren sollten praxisrelevante Fragestellungen beleuchtet werden.
From a documented past of the Jersey breed in Africa to a profit index linked future
(2022) Opoola, Oluyinka; Shumbusho, Felicien; Hambrook, David; Thomson, Sam; Dai, Harvey; Chagunda, Mizeck G. G.; Capper, Jude L.; Moran, Dominic; Mrode, Raphael; Djikeng, Appolinaire
The paper reports on the prevalence and performance of the Jersey cattle breed in Africa, highlighting its geographic distribution and describing the reported performance and other related characteristics from the early 1900s to the present day. The review examines the contribution of Jersey cattle in increasing the volume and efficiency of milk production across the continent. Data relating to the Jersey cattle breed has been reported in more than 30 African countries based on available material published between 1964 and 2020. A key encompassing parameter of any reference was a well-described consideration of the Jersey cattle breed (as pure or crossbred with other exotic and/or indigenous breeds) with reported performance within a variety of production systems and agro-ecologies in Africa. The main focus was on breed and performance parameters, breed types, percentage of different breed types in specific environments, reproduction method and fertility; survival and longevity; disease incidence; and production efficiency metrics such as: feed efficiency (milk unit per dry matter intake, DMI) and milk yield (MY) per unit of body weight (BW). The main performance descriptors identified were based on observations on resilience under both abiotic (heat, nutrition) and biotic (incidences of pests and diseases) stressors, milk production, BW, nutrition and utilisation of feed resources. From the literature consulted, we grouped key dairy cattle performance characteristics reported in each country under the following areas to aid comparisons; a. Milk production (Milk nutrient value, daily MY, lifetime MY and annual MY); b. Fertility traits and AFC; c. Survival and longevity, d. Production efficiency (Feed efficiency, milk per unit BW and milk per unit DMI and e. Disease incidences. Results of the review showed that the smaller stature and lower maintenance nutrient requirements of the Jersey breed means that it is better suited to tolerate the tropical production conditions in the African small-scale dairy farming sector. Detailed analyses on MY and survival showed that Jersey crosses with exotic and African indigenous breeds performed better than purebred cattle with strong evidence to support the suitability of the Jersey breed in crossbreeding with indigenous breeds for use in smallholder production systems.
Growth responses of three European weeds on different AMF species during early development
(2022) Säle, Verena; Sieverding, Ewald; Oehl, Fritz
Arbuscular mycorrhizal fungi (AMF) have multiple functions in agroecosystems and affect many processes below- and aboveground, including plant productivity. Mycorrhizal symbiosis is not necessarily beneficial for the host plant and the growth response can be not only positive but also neutral or negative. Among other factors, the responsiveness of plants to AMF depends on the plant-fungus combination. To find out whether the AMF species or isolate is a decisive factor for growth responses of weeds, 44 AMF isolates were tested in a pot experiment for their effects on three agricultural weeds: Echinochloa crus-galli, Solanum nigrum and Papaver rhoeas. The 44 isolates cover 18 AMF species from 13 genera and all 5 orders of the Glomeromycota. The aboveground biomass of the weeds was determined after different times of growth of each weed. In most cases, the effects of AMF isolates on weed growth were negative or neutral. We conclude that some weed species do not benefit from AMF in terms of growth. AMF species can even cause negative growth responses, an effect that may be of practical interest for organic farming where the aim is to obtain a high diversity and concentration of native AMF for the benefit of the cultivated crops without increasing the labor for mechanical weeding.
Potassium content is the main driver for salinity tolerance in sweet potato before tuber formation
(2022) Mondal, Shimul; Rahaman, Ebna Habib Md Shofiur; Asch, Folkard
Sweet potato (Ipomoea batatas L.) is mostly grown in Asia, which accounts for 86% of global production. However, its production is under threat by salinity. Little is known about genotypic responses to salinity in sweet potato. Phenotypic responses or physiological processes linked to salt tolerance that could be developed into a reliable screening tool to assist breeding have not yet been developed for sweet potato. In a hydroponic cultivation system, 12 contrasting sweet potato genotypes were subjected to 0, 50, 100 and 150 mM root zone salinity (RZS). Genotypic thresholds for dry matter accumulation and the genotypic slopes for additional dry matter reduction when the RZS increased beyond the genotypic threshold were determined. Sodium, chlorine and potassium (K) were determined from above‐ground biomass and correlated with the genotypic thresholds found. Genotypic threshold levels were linearly negatively correlated with the difference in tissue K content at 75 mM RZS and the tissue K content at control levels. Based on the genotypic ability to retain high tissue potassium levels under increasing RZS, we propose a screening tool based on these experimental data that can distinguish between salt‐tolerant and salt‐sensitive genotypes and indicate the potential yield level of the sweet potato genotypes.
Strategies to promote sustainable development: The gendered importance of addressing diminishing African Locust Bean (Parkia biglobosa) resources in northern Ghana’s agro-ecological landscape
(2022) Lelea, Margareta Amy; Konlan, Lydia Madintin; Ziblila, Rashida Chantima; Thiele, Lara Elena; Amo-Aidoo, Araba; Kaufmann, Brigitte
As the topic of gender and forests gains international attention through programs related to addressing the Sustainable Development Goals, we focus on a case study of the African Locust Bean (Parkia biglobosa) in the savannah landscape of northern Ghana. Although this tree holds high cultural significance for Dagomba women, it is unfortunately becoming scarcer in our study area near Tamale. We investigate the reasons for this decline in relation to the agricultural, ecological, and cultural landscape and discuss the gendered impacts of these changes. Research in these communities was conducted between 2018 and 2021 as part of a transdisciplinary action research approach to process underutilized species with women’s groups. The research started with a survey that included 27 women’s groups in 13 communities with 524 women participants. Out of a selected number of groups, our research team has worked more intensively with three women’s groups near Nyankpala, which selected for their processing focus the African Locust Bean, locally known as dawadawa. More than 45 group sessions were organized with seven groups in a collaborative learning process in 2019. Additionally, the three groups in Kpachi who chose to process the African Locust Bean sustained facilitation of group activities until the end of 2021. Specifically, on the topic of the decline of this tree, 19 semistructured interviews were conducted in August 2020 with 8 female farmers, 7 male farmers and 4 chiefs in the local governance system. Our results show the cultural significance of the African Locust Bean for women in the Dagomba culture as well as practical uses of all parts of the tree. Specifically, the seeds are used for making a fermented condiment and tea. Although seeds of the African Locust Bean are considered a women’s crop, their access to this tree is mediated by the local chiefs and often male land-users. Most farmers interviewed reported a reduction in trees in their fields. The reasons for the decrease can be summarized in six different categories, (1) aging tree populations, (2) challenge caring for saplings until maturity, (3) agricultural changes with increased mechanization and pesticide use, (4) over-use as a firewood resource, (5) usufruct rights between traditional chiefs, male land-owners, and women who should be granted access to the trees according to Dagomba cultural values, and (6) reduced water availability inhibits seed yield. In conclusion, there is an urgent need for action to protect and restore the African Locust Bean within northern Ghana’s savannah landscape to ensure continued access and benefits of the tree to women in the region.
Transplanting as an option to cope with abiotic stress in high‐altitude lowland rice production systems in East Africa
(2021) Abera, Bayuh Belay; Senthilkumar, Kalimuthu; Cotter, Marc; Asch, Folkard
The current practice of direct seeding in East‐African high‐altitude rice farming systems is constrained by water availability early in the season and low temperatures later in the season at the crop's critical reproductive stage. Thus, productivity is restricted as only short‐duration varieties can be grown due to the risk of crop failure. To fully exploit the yield potential of such rainfed systems, the best combination of crop establishment methods and climatic ‘best fit’ genotypes is required. In this study, nine rice genotypes were evaluated under direct seeding and transplanting in the 2016 and 2017 cropping seasons with the aim of identifying genotype by environment by management combinations best fitting the high‐altitude, rainfed rice production systems. On average across all genotypes, transplanting had a positive yield effect of 18% in 2016 and 23% in 2017. Regarding the phenological development, individual phenophases were not significantly affected by transplanting relative to direct seeding; however, vegetative development stages in transplanted rice tended to be about 15% longer than when direct seeded. Even though transplanting led to extended vegetative growth, the time in the nursery allowed the plants to escape the cold spell late in the season. The results from the current study provide options to adapt cropping calendars by combining genetic resources with targeted crop management, thus improving and stabilizing yields of rainfed lowland rice farming systems at high altitude.
Genetic and phenotypic correlations among feed efficiency, immune and production traits in indigenous chicken of Kenya
(2023) Miyumo, Sophie A.; Wasike, Chrilukovian B.; Ilatsia, Evans D.; Bennewitz, Jorn; Chagunda, Mizeck G. G.
This study aimed at estimating genetic and phenotypic relationships among feed efficiency, immune and production traits measured pre- (9–20 weeks of age) and post- (12 weeks from on-set of lay) maturity. Production traits were average daily gain (ADG) and average daily feed-intake (ADFI1) in the pre-maturity period and age at first egg (AFE), average daily feed-intake (ADFI2) and average daily egg mass (EM) in the post-maturity period. Feed efficiency comprised of residual feed intake (RFI) estimated in both periods. Natural antibodies binding to keyhole limpet hemocyanin (KLH-IgM) and specific antibodies binding to Newcastle disease virus (NDV-IgG) measured at 16 and 28 weeks of age represented immune traits pre- and post-maturity, respectively. In the growing period, 1,820 records on ADG, KLH-IgM and NDV-IgG, and 1,559 records on ADFI1 and RFI were available for analyses. In the laying period, 1,340 records on AFE, EM, KLH-IgM and NDV-IgG, and 1,288 records on ADFI2 and RFI were used in the analyses. Bi-variate animal mixed model was fitted to estimate (co)variance components, heritability and correlations among the traits. The model constituted sex, population, generation, line and genotype as fixed effects, and animal and residual effects as random variables. During the growing period, moderate to high heritability (0.36–0.68) was estimated for the production traits and RFI while the antibody traits had low (0.10–0.22) heritability estimates. Post-maturity, the production traits and RFI were moderately (0.30–0.37) heritable while moderate to high (0.25–0.41) heritability was estimated for the antibody traits. Genetic correlations between feed efficiency and production traits in both periods showed that RFI had negative genetic correlations with ADG (−0.47) and EM (−0.56) but was positively correlated with ADFI1 (0.60), ADFI2 (0.74) and AFE (0.35). Among immune and production traits, KLH-IgM and NDV-IgG had negative genetic correlations with ADG (−0.22; −0.56), AFE (−0.39; −0.42) and EM (−0.35; −0.16) but were positively correlated with ADFI1 (0.41; 0.34) and ADFI2 (0.47; 0.52). Genetic correlations between RFI with KLH-IgM (0.62; 0.33) and NDV-IgG (0.58; 0.50) were positive in both production periods. Feed intake, RFI and antibody traits measured in both production periods were positively correlated with estimates ranging from 0.48 to 0.82. Results from this study indicate selection possibilities to improve production, feed efficiency and immune-competence in indigenous chicken. The genetic correlations suggest that improved feed efficiency would be associated with high growth rates, early maturing chicken, high egg mass and reduced feed intake. In contrast, improved general (KLH-IgM) and specific (NDV-IgG) immunity would result in lower growth rates and egg mass but associated with early sexual maturation and high feed intake. Unfavorable genetic correlations between feed efficiency and immune traits imply that chicken of higher productivity and antibody levels will consume more feed to support both functions. These associations indicate that selective breeding for feed efficiency and immune-competence may have genetic consequences on production traits and should therefore be accounted for in indigenous chicken improvement programs
Estimating the quantum requirements for plant growth and related electricity demand for LED lighting systems
(2021) Schmierer, Marc; Brueck, Holger; Asch, Folkard; Sauerborn, Joachim
Indoor plant production systems with artificial lighting are considered an emerging technology contributing to biomass-based value webs. The viability of this concept greatly relies on the energy requirements (ER, Watt) for lighting. We estimated the ER for plant growth by calculating the conversion efficiency of electricity to light of solid-state light-emitting diodes (LED) and the quantum requirements for plant growth of a fictional plant stand producing 2500 g of dry weight per m2 of ground during 100 days, representing a high productivity benchmark of field crops. The quantum output (µmol s−1 W−1) of eight LEDs of different colours varied between 0.78 for green and 2.54 for deep red. Uncertainty in the H+ demand for ATP synthesis during photosynthesis, the relative portion of photorespiration and the fraction of light intercepted by plant canopies (fabs) were considered in a pessimistic (PA) and optimistic (OA) approach of calculation of ER. Cumulative ER were 606 and 265 kWh m−2 for the PA and OA scenarios. The energy conversion efficiencies in the PA and OA scenarios were 2.07 and 4.72%. Estimates of energy savings by suppressing photorespiration and increasing fabs vary between 24 and 38%. The peak daily ER were 9.44 and 4.14 kWh in the PA and OA scenarios. Results are discussed in the context of the design of lighting in indoor plant production systems and commercial greenhouses where natural fluctuation in solar radiation could be balanced by dimmable LED panels.
Inter-microbial competition for N and plant NO3− uptake rather than BNI determines soil net nitrification under intensively managed Brachiaria humidicola
(2021) Egenolf, Konrad; Schad, Philipp; Arevalo, Ashly; Villegas, Daniel; Arango, Jacobo; Karwat, Hannes; Cadisch, Georg; Rasche, Frank
Brachiaria humidicola (syn. Urochloa humidicola) has been acknowledged to control soil nitrification through release of nitrification inhibitors (NI), a phenomenon conceptualized as biological nitrification inhibition (BNI). Liming and N fertilization as features of agricultural intensification may suppress BNI performance, due to a decrease in NI exudation, increased NH3 availability and promotion of ammonia oxidizing bacteria (AOB) over archaea (AOA). A 2-year three-factorial pot trial was conducted to investigate the influence of soil pH and soil microbial background (ratio of archaea to bacteria) on BNI performance of B. humidicola. The study verified the capacity of B. humidicola to reduce net nitrification rates by 50 to 85% compared to the non-planted control, irrespective of soil pH and microbial background. The reduction of net nitrification, however, was largely dependent on microbial N immobilization and efficient plant N uptake. A reduction of gross nitrification could not be confirmed for the AOA dominated soil, but possibly contributed to reduced net nitrification rates in the AOB-dominated soil. However, this putative reduction of gross nitrification was attributed to plant-facilitated inter-microbial competition between bacterial heterotrophs and nitrifiers rather than BNI. It was concluded that BNI may play a dominant role in extensive B. humidicola pasture systems, while N immobilization and efficient plant N uptake may display the dominant factors controlling net nitrification rates under intensively managed B. humidicola.

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