Fakultät Agrarwissenschaften

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Die Fakultät entwickelt in Lehre und Forschung nachhaltige Produktionstechniken der Agrar- und Ernährungswirtschaft. Sie erarbeitet Beiträge für den ländlichen Raum und zum Verbraucher-, Tier- und Umweltschutz.

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A low-tech approach to mobilize nutrients from organic residues to produce bioponic stock solutions
(2024) Heintze, Sebastian; Beckett, Marc; Kriem, Lukas Simon; Germer, Jörn; Asch, Folkard; Heintze, Sebastian; Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstr. 12, 70569 Stuttgart, Germany; (S.H.); (L.S.K.); Beckett, Marc; Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstr. 12, 70569 Stuttgart, Germany; (S.H.); (L.S.K.); Kriem, Lukas Simon; Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstr. 12, 70569 Stuttgart, Germany; (S.H.); (L.S.K.); Germer, Jörn; Hans-Ruthenberg Institute for Tropical Agricultural Sciences, University of Hohenheim, Garbenstr. 13, 70599 Stuttgart, Germany; (J.G.); (F.A.); Asch, Folkard; Hans-Ruthenberg Institute for Tropical Agricultural Sciences, University of Hohenheim, Garbenstr. 13, 70599 Stuttgart, Germany; (J.G.); (F.A.); Liu, Guodong
Organic residues, as a nutrient source suitable of producing solutions for hydroponic crop production, have the potential to reduce the dependence on mineral fertilizers. Especially in remote and resource-constrained regions, organic residues might be the only option to produce hydroponic nutrient solutions. However, nutrient solutions made from organic residues, called bioponic solutions, are usually unbalanced in their nutrient composition, which leads to deficiencies and poor plant growth. This study aimed to experimentally develop a low-tech approach to produce bioponic stock solutions rich in NO3−, P, and K, to create a balanced bioponic solution. The mixed bioponic solution contained 58 mg L−1 NH4+-N, 43 mg L−1 NO3−-N, 50 mg L−1 PO43−-P, and 246 mg L−1 K+. This approach resulted in satisfactory levels of P, K and micronutrients. The solution was tested pure and spiked with Ca(NO3)2 on lettuce in comparison with a mineral Hoagland nutrient solution. Neither the bioponic nor the spiked bioponic solution achieved comparable lettuce yields to the Hoagland solution. The poor growth of the plants in the bioponic solution was attributed to an unfavorable NH4+:NO3− ratio, high microorganism load, and elevated pH levels. However, the approach of preparing bioponic stock solutions could be promising for future research into the production of balanced bioponic nutrient solutions from organic residues.
The active core microbiota of two high-yielding laying hen breeds fed with different levels of calcium and phosphorus
(2022) Roth, Christoph; Sims, Tanja; Rodehutscord, Markus; Seifert, Jana; Camarinha-Silva, Amélia
The nutrient availability and supplementation of dietary phosphorus (P) and calcium (Ca) in avian feed, especially in laying hens, plays a vital role in phytase degradation and mineral utilization during the laying phase. The required concentration of P and Ca peaks during the laying phase, and the direct interaction between Ca and P concentration shrinks the availability of both supplements in the feed. Our goal was to characterize the active microbiota of the entire gastrointestinal tract (GIT) (crop, gizzard, duodenum, ileum, caeca), including digesta- and mucosa-associated communities of two contrasting high-yielding breeds of laying hens (Lohmann Brown Classic, LB; Lohmann LSL-Classic, LSL) under different P and Ca supplementation levels. Statistical significances were observed for breed, GIT section, Ca, and the interaction of GIT section x breed, P x Ca, Ca x breed and P x Ca x breed (p < 0.05). A core microbiota of five species was detected in more than 97% of all samples. They were represented by an uncl. Lactobacillus (average relative abundance (av. abu.) 12.1%), Lactobacillus helveticus (av. abu. 10.8%), Megamonas funiformis (av. abu. 6.8%), Ligilactobacillus salivarius (av. abu. 4.5%), and an uncl. Fusicatenibacter (av. abu. 1.1%). Our findings indicated that Ca and P supplementation levels 20% below the recommendation have a minor effect on the microbiota compared to the strong impact of the bird’s genetic background. Moreover, a core active microbiota across the GIT of two high-yielding laying hen breeds was revealed for the first time.
Assessing functional properties of diet protein hydrolysate and oil from fish waste on canine immune parameters, cardiac biomarkers, and fecal microbiota
(2024) Cabrita, Ana R. J.; Barroso, Carolina; Fontes-Sousa, Ana Patrícia; Correia, Alexandra; Teixeira, Luzia; Maia, Margarida R. G.; Vilanova, Manuel; Yergaliyev, Timur; Camarinha-Silva, Amélia; Fonseca, António J. M.; Cabrita, Ana R. J.; REQUIMTE, Network of Chemistry and Technology, LAQV, Laboratory for Green Chemistry, ICBAS, School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal; Barroso, Carolina; REQUIMTE, Network of Chemistry and Technology, LAQV, Laboratory for Green Chemistry, ICBAS, School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal; Fontes-Sousa, Ana Patrícia; Department of Immuno-Physiology and Pharmacology, Center for Pharmacological Research and Drug Innovation (MedInUP), ICBAS, School of Medicine and Biomedical Sciences, Veterinary Hospital of the University of Porto (UPVET), University of Porto, Porto, Portugal; Correia, Alexandra; ICBAS – School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal; Teixeira, Luzia; ICBAS – School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal; Maia, Margarida R. G.; REQUIMTE, Network of Chemistry and Technology, LAQV, Laboratory for Green Chemistry, ICBAS, School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal; Vilanova, Manuel; ICBAS – School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal; Yergaliyev, Timur; HoLMiR – Hohenheim Center for Livestock Microbiome Research, University of Hohenheim, Stuttgart, Germany; Camarinha-Silva, Amélia; HoLMiR – Hohenheim Center for Livestock Microbiome Research, University of Hohenheim, Stuttgart, Germany; Fonseca, António J. M.; REQUIMTE, Network of Chemistry and Technology, LAQV, Laboratory for Green Chemistry, ICBAS, School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal
Locally produced fish hydrolysate and oil from the agrifood sector comprises a sustainable solution both to the problem of fish waste disposal and to the petfood sector with potential benefits for the animal’s health. This study evaluated the effects of the dietary replacement of mainly imported shrimp hydrolysate (5%) and salmon oil (3%; control diet) with locally produced fish hydrolysate (5%) and oil (3.2%) obtained from fish waste (experimental diet) on systemic inflammation markers, adipokines levels, cardiac function and fecal microbiota of adult dogs. Samples and measurements were taken from a feeding trial conducted according to a crossover design with two diets (control and experimental diets), six adult Beagle dogs per diet and two periods of 6 weeks each. The experimental diet, with higher docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids contents, decreased plasmatic triglycerides and the activity of angiotensin converting enzyme, also tending to decrease total cholesterol. No effects of diet were observed on serum levels of the pro-inflammatory cytokines interleukin (IL)-1β, IL-8, and IL-12/IL-23 p40, and of the serum levels of the anti-inflammatory adipokine adiponectin. Blood pressure, heart rate and echocardiographic measurements were similar between diets with the only exception of left atrial to aorta diameter ratio that was higher in dogs fed the experimental diet, but without clinical relevance. Diet did not significantly affect fecal immunoglobulin A concentration. Regarding fecal microbiome, Megasphaera was the most abundant genus, followed by Bifidobacterium , Fusobacterium , and Prevotella , being the relative abundances of Fusobacterium and Ileibacterium genera positively affected by the experimental diet. Overall, results from the performed short term trial suggest that shrimp hydrolysate and salmon oil can be replaced by protein hydrolysate and oil from fish by-products without affecting systemic inflammatory markers, cardiac structure and function, but potentially benefiting bacterial genera associated with healthy microbiome. Considering the high DHA and EPA contents and the antioxidant properties of fish oil and hydrolysate, it would be worthwhile in the future to assess their long-term effects on inflammatory markers and their role in spontaneous canine cardiac diseases and to perform metabolomic and metagenomics analysis to elucidate the relevance of microbiota changes in the gut.
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.
Combining improved mungbean cultivars with plant growth promoting rhizobacteria inoculation and regulated deficit irrigation to increase crop productivity
(2024) Pataczek, Lisa; Cadisch, Georg
The cultivation of legumes provides an approach to sustainably intensify agricultural production, since short-duration legumes can fit into existing cereal-based cropping systems, diversifying farm incomes and farmers diets, as well as providing environmental benefits through the fixation of atmospheric N2 and, thus, enhancing yields of following crops. Mungbean is a legume, which plays already an important role in the traditional nutrition of people in the Global South. Its nutritious seeds can improve food security and the short growing duration facilitates the diversification of mainly cereal-based crop rotations. However, yields are low and may even become lower in future in the face of climate change. Main constraints of mungbean cultivation include pest and diseases, as well as heat, drought and soil salinity due to inappropriate irrigation techniques or saline ground water. The main aim of this thesis was therefore to analyse the effects of more advanced cultivation techniques, i.e. the use of plant growth promoting rhizobacteria (PGPR) and regulated deficit irrigation (RDI), on the productivity and nitrogen (N) fixation capacity of improved mungbean (Vigna radiata L.) cultivars, resistant and/or tolerant to pests, diseases, heat and soil salinity. An extended literature review was conducted to summarize the current understanding of the use of PGPRs and the effect on crop productivity, especially on marginal land (Chapter 2). The use of PGPRs can on the one hand side increase plant growth through direct and indirect mechanisms, such as BNF, hormone production and nutrient solubilization or the production of antibiotics to suppress phytodiseases. Especially 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity plays a significant role to reduce the negative impact of stress environments. On the other side PGPRs can be used to remediate decontaminated sites, through metabolic capabilities, transforming for instance aromatic compounds into less toxic compounds, or the biodegradation of pesticides and organic pollutants. Since ACC deaminase-producing bacteria are also supposed to enhance root growth, it is assumed that they can potentially increase soil N uptake and/or infection sites for rhizobia to biologically fix atmospheric N2 (BNF). In order to test the effect of ACC deaminase-producing PGPRs on mungbean productivity and N accumulation, three strains were tested as single- or multistrain inoculation in the field: Rhizobium phaseoli, Bacillus subtilis and Pseudomonas fluorescens (Chapter 3). Their effect on one improved mungbean cultivar (NM11, resistant to the Mungbean Yellow Mosaic Disease) was assessed on two research sites in Faisalabad, Pakistan. The impact of the strains differed significantly, with no effect on productivity (total biomass, seed yield) or total N accumulation (BNF and soil-N uptake) with multi-strain inoculation of all strains and single-strain inoculation of P. fluorescens. Inoculation with B. subtilis did, however, result in significantly increased dry matter (roots: +211 kg ha-1, total dry matter: +1.7 t ha-1), and total plant-N (+36 kg ha-1), while R. phaseoli inoculation enhanced BNF (+24%). The results suggested that only the single strain inoculation of B. subtilis and R. phaseoli was promising in terms of productivity increase, however, the choice of the strain should be made according to the soil-N status: low soil-N favors R. phaseoli inoculation, while medium to high soil-N would rather point towards the use of B. subtilis. The improved mungbean cultivar NM11 was additionally tested together with three other improved cultivars (AVMU 1604, AVMU 1635 and KPS2, resistant/tolerant to powdery mildew, bruchids and heat and salt, respectively), in combination with RDI in a greenhouse trial at the University of Hohenheim (Chapter 4). The aim was to identify differences in drought adaptation strategies between the cultivars in terms of dry matter partitioning, yield, harvest index, pod harvest index, water use efficiency and carbon-13 isotope discrimination. Levels of water deficit as depletion fractions (%) of total available soil water were set to 0.45, 0.65 and 0.8, corresponding to recommended irrigation, moderate and severe water deficit, respectively. The cultivars differed in their drought resistance strategies, exhibiting either drought escape, avoidance, tolerance or a combination of several strategies. The cultivar KPS2 showed mainly a drought escape mechanism through faster development, stable yields and greatest harvest index/pod harvest index (36%/69%) across all RDI treatments and cultivars. The cultivar AVMU 1604 displayed mainly a mixture of drought avoidance and escape through increased remobilization of assimilates from vegetative plant parts to pods/seeds, resulting in greater yield under water deficit by 52%. The choice of a cultivar for the field should be based, thus, on the prevailing climatic conditions (season and region): KPS2 can grow in areas with terminate drought conditions, whereas AVMU 1604 can tolerate intermittent drought conditions. The results of this thesis showed that ACC deaminase-producing PGPRs can substantially affect N uptake, although this effect is barely discussed in literature. Moreover, improved mungbean cultivars, exhibiting already a range of tolerances and resistances to certain pests and diseases, showed a great potential in adapting to drought conditions, representing a viable option for cultivation under increasing abiotic and biotic stress factors in the face of climate change.
Composition of the ileum microbiota is a mediator between the host genome and phosphorus utilization and other efficiency traits in Japanese quail (Coturnix japonica)
(2022) Haas, Valentin; Vollmar, Solveig; Preuß, Siegfried; Rodehutscord, Markus; Camarinha-Silva, Amélia; Bennewitz, Jörn; Haas, Valentin; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Vollmar, Solveig; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Preuß, Siegfried; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Rodehutscord, Markus; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Camarinha-Silva, Amélia; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Bennewitz, Jörn; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany
Background: Phosphorus is an essential nutrient in all living organisms and, currently, it is the focus of much attention due to its global scarcity, the environmental impact of phosphorus from excreta, and its low digestibility due to its storage in the form of phytates in plants. In poultry, phosphorus utilization is influenced by composition of the ileum microbiota and host genetics. In our study, we analyzed the impact of host genetics on composition of the ileum microbiota and the relationship of the relative abundance of ileal bacterial genera with phosphorus utilization and related quantitative traits in Japanese quail. An F2 cross of 758 quails was genotyped with 4k genome-wide single nucleotide polymorphisms (SNPs) and composition of the ileum microbiota was characterized using target amplicon sequencing. Heritabilities of the relative abundance of bacterial genera were estimated and quantitative trait locus (QTL) linkage mapping for the host was conducted for the heritable genera. Phenotypic and genetic correlations and recursive relationships between bacterial genera and quantitative traits were estimated using structural equation models. A genomic best linear unbiased prediction (GBLUP) and microbial (M)BLUP hologenomic selection approach was applied to assess the feasibility of breeding for improved phosphorus utilization based on the host genome and the heritable part of composition of the ileum microbiota. Results: Among the 59 bacterial genera examined, 24 showed a significant heritability (nominal p ≤ 0.05), ranging from 0.04 to 0.17. For these genera, six genome-wide significant QTL were mapped. Significant recursive effects were found, which support the indirect host genetic effects on the host’s quantitative traits via microbiota composition in the ileum of quail. Cross-validated microbial and genomic prediction accuracies confirmed the strong impact of microbial composition and host genetics on the host’s quantitative traits, as the GBLUP accuracies based on the heritable microbiota-mediated components of the traits were similar to the accuracies of conventional GBLUP based on genome-wide SNPs. Conclusions: Our results revealed a significant effect of host genetics on composition of the ileal microbiota and confirmed that host genetics and composition of the ileum microbiota have an impact on the host’s quantitative traits. This offers the possibility to breed for improved phosphorus utilization based on the host genome and the heritable part of composition of the ileum microbiota.
Computational sizing of solar powered peanut oil extraction in Senegal using a synthetic load profile
(2024) Bonzi, Wiomou Joévin; Romuli, Sebastian; Diouf, Djicknoum; Piriou, Bruno; Meissner, Klaus; Müller, Joachim
This paper presents an approach for sizing a hybrid photovoltaic system for a small-scale peanut oil processing company (Yaye Aissatou, Passy) in rural Senegal using a synthetic load profile. In this study, a predictive model of the electrical load of a service-based plant oil processing company was developed through a diagnosis, to evaluate the extraction process. The mass and energy balance were measured, and the process was implemented into MATLAB Simulink. The simulated load profile was implemented in HOMER Pro and the characteristics of the most profitable hybrid systems were identified. The results showed that the lowest net present cost over 25 years was found with a PV/battery/grid-system with 18.6 kWp solar panels, 16 kWh of storage, and an initial investment of 20,019 €. Compared to a grid-only scenario, this solution reduces the net present cost from an initial 72,163 € to 31,603 €, the operating cost from 3675 € per year to 590 € per year, and the cost of energy from 0.29 to 0.13 €/kWh. The renewable fraction of the proposed system is 90.0 % while the expected payback period is 6.2 years. The study demonstrates the economic feasibility of using solar energy for plant oil processing.
Computing optimal allocation of trials to subregions in crop‐variety testing in case of correlated genotype effects
(2025) Prus, Maryna; Prus, Maryna; Biostatistics Unit (340c), Institute of Crop Science, University of Hohenheim, Stuttgart, Germany
The subject of this work is the allocation of trials to subregions in crop variety testing in the case of correlated genotype effects. A solution for computation of optimal allocations using the OptimalDesign package in R is proposed. The obtained optimal designs minimize linear criteria based on the mean squared error matrix of the best linear unbiased prediction of the genotype effects. The proposed computational approach allows for any kind of additional linear constraint on the designs. The results are illustrated by a real data example.
Cow’s microbiome from antepartum to postpartum: a long-term study covering two physiological challenges
(2022) Tröscher-Mußotter, Johanna; Deusch, Simon; Borda-Molina, Daniel; Frahm, Jana; Dänicke, Sven; Camarinha-Silva, Amélia; Huber, Korinna; Seifert, Jana
Little is known about the interplay between the ruminant microbiome and the host during challenging events. This long-term study investigated the ruminal and duodenal microbiome and metabolites during calving as an individual challenge and a lipopolysaccharide-induced systemic inflammation as a standardized challenge. Strong inter- and intra-individual microbiome changes were noted during the entire trial period of 168 days and between the 12 sampling time points. Bifidobacterium increased significantly at 3 days after calving. Both challenges increased the intestinal abundance of fiber-associated taxa, e.g., Butyrivibrio and unclassified Ruminococcaceae. NMR analyses of rumen and duodenum samples identified up to 60 metabolites out of which fatty and amino acids, amines, and urea varied in concentrations triggered by the two challenges. Correlation analyses between these parameters indicated a close connection and dependency of the microbiome with its host. It turns out that the combination of phylogenetic with metabolite information supports the understanding of the true scenario in the forestomach system. The individual stages of the production cycle in dairy cows reveal specific criteria for the interaction pattern between microbial functions and host responses.
Diacetoxyscirpenol, a Fusarium exometabolite, prevents efficiently the incidence of the parasitic weed Striga hermonthica
(2022) Anteyi, Williams Oyifioda; Klaiber, Iris; Rasche, Frank; Anteyi, Williams Oyifioda; Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, Stuttgart, Germany; Klaiber, Iris; Core Facility Hohenheim, University of Hohenheim, Stuttgart, Germany; Rasche, Frank; Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, Stuttgart, Germany
Background: Certain Fusarium exometabolites have been reported to inhibit seed germination of the cereal-parasitizing witchweed, Striga hermonthica , in vitro . However, it is unknown if these exometabolites will consistently prevent S. hermonthica incidence in planta . The study screened a selection of known, highly phytotoxic Fusarium exometabolites, in identifying the most potent/efficient candidate (i.e., having the greatest effect at minimal concentration) to completely hinder S. hermonthica seed germination in vitro and incidence in planta , without affecting the host crop development and yield. Results: In vitro germination assays of the tested Fusarium exometabolites (i.e., 1,4-naphthoquinone, equisetin, fusaric acid, hymeglusin, neosolaniol (Neo), T-2 toxin (T-2) and diacetoxyscirpenol (DAS)) as pre- Striga seed conditioning treatments at 1, 5, 10, 20, 50 and 100 µM, revealed that only DAS, out of all tested exometabolites, completely inhibited S. hermonthica seed germination at each concentration. It was followed by T-2 and Neo, as from 10 to 20 µM respectively. The remaining exometabolites reduced S. hermonthica seed germination as from 20 µM ( P < 0. 0001). In planta assessment (in a S. hermonthica -sorghum parasitic system) of the exometabolites at 20 µM showed that, although, none of the tested exometabolites affected sorghum aboveground dry biomass ( P > 0.05), only DAS completely prevented S. hermonthica incidence. Following a 14-d incubation of DAS in the planting soil substrate, bacterial 16S ribosomal RNA (rRNA) and fungal 18S rRNA gene copy numbers of the soil microbial community were enhanced; which coincided with complete degradation of DAS in the substrate. Metabolic footprinting revealed that the S. hermonthica mycoherbicidal agent, Fusarium oxysporum f. sp. strigae (isolates Foxy-2, FK3), did not produce DAS; a discovery that corresponded with underexpression of key genes (Tri5, Tri4) necessary for Fusarium trichothecene biosynthesis ( P < 0.0001). Conclusions: Among the tested Fusarium exometabolites, DAS exhibited the most promising herbicidal potential against S. hermonthica . Thus, it could serve as a new biocontrol agent for efficient S. hermonthica management. Further examination of DAS specific mode of action against the target weed S. hermonthica at low concentrations (≤ 20 µM), as opposed to non-target soil organisms, is required.
Disc mower versus bar mower: Evaluation of the direct effects of two common mowing techniques on the grassland arthropod fauna
(2025) von Berg, Lea; Frank, Jonas; Betz, Oliver; Steidle, Johannes L. M.; Böttinger, Stefan; Sann, Manuela; von Berg, Lea; Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology, University of Tübingen, Tübingen, Germany; Frank, Jonas; Fundamentals of Agricultural Engineering, Institute for Agricultural Engineering, University of Hohenheim, Stuttgart, Germany; Betz, Oliver; Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology, University of Tübingen, Tübingen, Germany; Steidle, Johannes L. M.; Chemical Ecology, Institute for Biology, University of Hohenheim, Stuttgart, Germany; Böttinger, Stefan; Fundamentals of Agricultural Engineering, Institute for Agricultural Engineering, University of Hohenheim, Stuttgart, Germany; Sann, Manuela; Chemical Ecology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
1. In Central Europe, species‐rich grasslands are threatened by intensive agriculture with frequent mowing, contributing to the reduction of arthropods such as insects and spiders. However, comprehensive and standardised studies on the direct effects of the two most agriculturally relevant mowing techniques, e.g., double‐blade bar mower versus disc mower, are lacking. 2. In a 2‐year experiment, we have investigated the direct effect of mowing on eight abundant arthropod groups in grassland, covering two seasonal mowing events in both years, using a randomised block design. We compared (a) an unmown control, (b) a double‐blade bar mower and (c) a disc mower. 3. For most of the taxonomic groups studied, a significantly lower number of individuals was found in the experimental plots immediately after mowing, regardless of the mowing technique, compared to an unmown control. This was not the case for Orthoptera and Coleoptera, which did not show a significant reduction in the number of individuals for both mowing techniques (Orthoptera) or only for the double‐blade bar mower (Coleoptera). 4. Between both mowing techniques, no significant differences were found for all taxonomic groups investigated. 5. Synthesis and applications: Our findings suggest that mowing in general has a negative impact on abundant arthropod groups in grassland, regardless of the method used. Tractor‐driven double‐blade bar mowers do not seem to be a truly insect‐friendly alternative to a conventional disc mower. Other factors such as cutting height and mowing regimes should be seriously considered to protect spiders and insects from the negative effects of mowing. In addition, we strongly recommend the maintenance of unmown refugia. Insects and spiders that are spared by mowing can take refuge in these unmown areas to avoid subsequent harvesting and thermally unfavourable conditions that arise on mown areas. Further, unmown refugia are basic habitat structures for a subsequent recolonisation of mown areas once the flora has recovered.
Do we need post-tree thinning management? Prescribed fire and goat browsing to control woody encroacher species in an Ethiopian savanna
(2024) Abate, Teshome; Abebe, Tesfaye; Treydte, Anna; Abate, Teshome; College of Agriculture, Hawassa University, Hawassa, Ethiopia; Abebe, Tesfaye; College of Agriculture, Hawassa University, Hawassa, Ethiopia; Treydte, Anna; Department of Sustainable Agriculture and Biodiversity Conservation, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
Worldwide, bush encroachment threatens rangeland ecosystem services, including plant biodiversity and forage for livestock. Various control methods for encroaching woody species and restoring herbaceous vegetation exist but have rarely been explored experimentally. We assessed the impact of post-tree thinning management on tree mortality, the herbaceous community, and overall rangeland condition in Borana, an Ethiopian savanna ecosystem. At two 1.4 ha areas of encroached mono-specific Vachellia drepanolobium (whistling thorn) stands, we set up twenty-four 20 × 10 m experimental plots with four post-tree-thinning treatments (goat browsing only (1), prescribed fire (2), fire and goat browsing (3), and control (4) (i.e., no management after tree cutting), with three replications in a complete block design. Over two growing periods, we monitored resulting tree mortality, coppicing, seedling mortality and recruitment, as well as herbaceous layer attributes (diversity, biomass) and overall rangeland condition. All three post-tree thinning management scenarios significantly enhanced tree mortalities, reduced seedling recruitment and increased the abundance of the dominant desirable grass species. Prescribed fire and fire and goat-browsing treatments resulted in significantly greater grass and forb species richness, forb diversity, and biomass, as well as the overall rangeland condition compared to goat browsing only and the control treatment. However, grass species diversity did not respond to treatments. Post-tree management significantly increased tree mortality, reduced seedling recruitment, and increased the abundance of desirable grass species. Our findings strongly suggest that post-thinning management, particularly prescribed fire or a combination of fire and browsing, is highly effective in suppressing woody encroachment and improving biomass and overall rangeland condition.
Effects of different ground segmentation methods on the accuracy of UAV-based canopy volume measurements
(2024) Han, Leng; Wang, Zhichong; He, Miao; He, Xiongkui; Han, Leng; College of Science, China Agricultural University, Beijing, China; Wang, Zhichong; Tropics and Subtropics Group, Institute of Agricultural Engineering, University of Hohenheim, Stuttgart, Germany; He, Miao; College of Science, China Agricultural University, Beijing, China; He, Xiongkui; College of Science, China Agricultural University, Beijing, China
The nonuniform distribution of fruit tree canopies in space poses a challenge for precision management. In recent years, with the development of Structure from Motion (SFM) technology, unmanned aerial vehicle (UAV) remote sensing has been widely used to measure canopy features in orchards to balance efficiency and accuracy. A pipeline of canopy volume measurement based on UAV remote sensing was developed, in which RGB and digital surface model (DSM) orthophotos were constructed from captured RGB images, and then the canopy was segmented using U-Net, OTSU, and RANSAC methods, and the volume was calculated. The accuracy of the segmentation and the canopy volume measurement were compared. The results show that the U-Net trained with RGB and DSM achieves the best accuracy in the segmentation task, with mean intersection of concatenation (MIoU) of 84.75% and mean pixel accuracy (MPA) of 92.58%. However, in the canopy volume estimation task, the U-Net trained with DSM only achieved the best accuracy with Root mean square error (RMSE) of 0.410 m 3 , relative root mean square error (rRMSE) of 6.40%, and mean absolute percentage error (MAPE) of 4.74%. The deep learning-based segmentation method achieved higher accuracy in both the segmentation task and the canopy volume measurement task. For canopy volumes up to 7.50 m 3 , OTSU and RANSAC achieve an RMSE of 0.521 m 3 and 0.580 m 3 , respectively. Therefore, in the case of manually labeled datasets, the use of U-Net to segment the canopy region can achieve higher accuracy of canopy volume measurement. If it is difficult to cover the cost of data labeling, ground segmentation using partitioned OTSU can yield more accurate canopy volumes than RANSAC.
Efficacy of various mechanical weeding methods - single and in combination - in terms of different field conditions and weed densities
(2021) Naruhn, Georg-Peter; Peteinatos, Gerassimos G.; Butz, Andreas F.; Möller, Kurt; Gerhards, Roland
Public awareness and environmental policies have increased interest in applying non-herbicide weed control methods in conventional farming systems. Even though mechanical weed control has been used for centuries in agricultural practice, continuous developments—both in terms of implements and automation technologies—are continuously improving the potential outcomes. Current mechanical weed control methods were evaluated for their weed control efficacy and effects on yield potential against their equivalent herbicide methods. Furthermore, not much is known about the correlation between weed control efficacy (WCE) of different mechanical methods at varying weed density levels. A total of six experiments in winter wheat (2), peas (2), and soybean (2) were carried out in the years 2018, 2019, and 2020 in southwestern Germany. Harrowing and hoeing treatments at different speeds were carried out and compared to the herbicide treatments and untreated control plots. Regarding the average WCE, the combination of harrowing and hoeing was both the strongest (82%) and the most stable (74–100%) mechanical treatment in the different weed density levels. Whereas, in average, hoeing (72%) and harrowing (71%) were on the same WCE level, but harrowing (49–82%) was more stable than hoeing (40–99%). The grain yields in winter wheat varied between 4.1 Mg∙ha−1 (control) and 6.3 Mg∙ha−1 (harrow), in pea between 2.8 Mg∙ha−1 (hoe slow) and 5.7 Mg∙ha−1 (hoe fast) and in soybean between 1.7 Mg∙ha−1 (control) and 4 Mg∙ha−1 (herbicide). However, there were no significant differences in most cases. The results have shown that it is not possible to pinpoint a specific type of treatment as the most appropriate method for this cultivation, across all of the different circumstances. Different field and weather conditions can heavily affect and impact the expected outcome, giving, each time, an advantage for a specific type of treatment.
Exploring the plausibility of inoculated cowpeas as a climate adaptation strategy for Namibian smallholder farmers
(2025) Rasche, Livia; Katjana, Johannes; Jantke, Kerstin; Uchezuba, David; Schneider, Uwe A.; Rasche, Livia; Research Unit Sustainability and Climate Risks, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, 20144 Hamburg, Germany; Katjana, Johannes; School of Agriculture and Natural Resource Sciences, Namibia University of Science and Technology, Windhoek 10005, Namibia; Jantke, Kerstin; Research Unit Sustainability and Climate Risks, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, 20144 Hamburg, Germany; Uchezuba, David; School of Agriculture and Natural Resource Sciences, Namibia University of Science and Technology, Windhoek 10005, Namibia; Schneider, Uwe A.; Research Unit Sustainability and Climate Risks, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, 20144 Hamburg, Germany; Lombardi, Mariarosaria
Increased cultivation of cowpeas is a possible adaptation option for Namibian farmers under changing climatic conditions. Using inoculated cowpeas can potentially double the yields under favorable climate conditions. But is such a potentially beneficial agricultural adaptation technique likely to be adopted? We surveyed 90 cowpea farmers from 30 villages in the Kavango region of northern Namibia on their households and farms, access to institutions and services, food consumption and preferences, and perceptions of climate change. Our survey reveals that smallholder farmers will not readily adopt the new technology. At most, about 50% of farmers can be convinced by new information to change their agricultural activities. When specifically asked about their willingness to grow inoculated cowpeas, almost all farmers responded that they would be willing to do so. However, the farmers are reluctant to allocate more land for cowpea cultivation, mainly because harvesting is very time and labor-intensive. The study shows that technology assessments should be conducted in combination with socio-economic assessments to realistically assess the potential success of proposed adaptation measures, as the extent to which a new technology may be adopted is an essential indicator for justifying funding of new technologies or adaptation programs.
Food informatics - Review of the current state-of-the-art, revised definition, and classification into the research landscape
(2021) Krupitzer, Christian; Stein, Anthony
Background: The increasing population of humans, changing food consumption behavior, as well as the recent developments in the awareness for food sustainability, lead to new challenges for the production of food. Advances in the Internet of Things (IoT) and Artificial Intelligence (AI) technology, including Machine Learning and data analytics, might help to account for these challenges. Scope and Approach: Several research perspectives, among them Precision Agriculture, Industrial IoT, Internet of Food, or Smart Health, already provide new opportunities through digitalization. In this paper, we review the current state-of-the-art of the mentioned concepts. An additional concept is Food Informatics, which so far is mostly recognized as a mainly data-driven approach to support the production of food. In this review paper, we propose and discuss a new perspective for the concept of Food Informatics as a supportive discipline that subsumes the incorporation of information technology, mainly IoT and AI, in order to support the variety of aspects tangent to the food production process and delineate it from other, existing research streams in the domain. Key Findings and Conclusions: Many different concepts related to the digitalization in food science overlap. Further, Food Informatics is vaguely defined. In this paper, we provide a clear definition of Food Informatics and delineate it from related concepts. We corroborate our new perspective on Food Informatics by presenting several case studies about how it can support the food production as well as the intermediate steps until its consumption, and further describe its integration with related concepts.
Genetic architecture underlying the expression of eight α-amylase trypsin inhibitors
(2021) El Hassouni, Khaoula; Sielaff, Malte; Curella, Valentina; Neerukonda, Manjusha; Leiser, Willmar; Würschum, Tobias; Schuppan, Detlef; Tenzer, Stefan; Longin, C. Friedrich H.
Amylase trypsin inhibitors (ATIs) are important allergens in baker’s asthma and suspected triggers of non-celiac wheat sensitivity (NCWS) inducing intestinal and extra-intestinal inflammation. As studies on the expression and genetic architecture of ATI proteins in wheat are lacking, we evaluated 149 European old and modern bread wheat cultivars grown at three different field locations for their content of eight ATI proteins. Large differences in the content and composition of ATIs in the different cultivars were identified ranging from 3.76 pmol for ATI CM2 to 80.4 pmol for ATI 0.19, with up to 2.5-fold variation in CM-type and up to sixfold variation in mono/dimeric ATIs. Generally, heritability estimates were low except for ATI 0.28 and ATI CM2. ATI protein content showed a low correlation with quality traits commonly analyzed in wheat breeding. Similarly, no trends were found regarding ATI content in wheat cultivars originating from numerous countries and decades of breeding history. Genome-wide association mapping revealed a complex genetic architecture built of many small, few medium and two major quantitative trait loci (QTL). The major QTL were located on chromosomes 3B for ATI 0.19-like and 6B for ATI 0.28, explaining 70.6 and 68.7% of the genotypic variance, respectively. Within close physical proximity to the medium and major QTL, we identified eight potential candidate genes on the wheat reference genome encoding structurally related lipid transfer proteins. Consequently, selection and breeding of wheat cultivars with low ATI protein amounts appear difficult requiring other strategies to reduce ATI content in wheat products.
Genetics and breeding for humoral immunity and feed efficiency in indigenous chicken population in Kenya
(2024) Miyumo, Sophie; Chagunda, Mizeck G. G.
Indigenous chicken (IC) population contribute to food, nutrition, livelihood and economic security in many rural households in developing countries in the tropical regions. Despite their contribution, IC are predominantly raised under challenging free-range systems which limit their optimal production potential and utilization. Of significance, are disease morbidity and scarcity of feed resources. Indigenous chicken are exposed to a myriad of pathogens that cause various poultry diseases which result to massive production and economic losses. Among these diseases is Newcastle disease (NCD) which is endemic in the tropics and is considered important because of high prevalence and mortality rates. Seasonal variation in availability and quality of feed resources have a negative impact on production costs and performance of chicken. Furthermore, with climate change effects, environmental conditions are expected to significantly impact feed availability and pathogen epidemiology. Selective breeding for disease resistance and feed efficiency traits is an avenue through which individuals that are adaptative to disease-prone production environments, with ability to efficiently convert available feed resources into products and support their maintenance requirements can be sustainably produced. Therefore, this thesis aimed to generate information that can guide breeding decisions on selection for improved health and efficient production to enhance the overall performance of the indigenous chicken population in Kenya. Chapter 1 presented an overview on the relevance of indigenous chicken genetic resources in developing countries with respect to their proportion among chicken population, contribution at household and national levels, and adaptive capacity to local environments. The challenges experienced in IC production systems in developing countries and their impacts on productivity and profitability, with a focus on diseases and scarcity in feed resources were addressed in this chapter. Management strategies practiced on-farm to control diseases and cope with seasonal availability of feed resources and the limitations of these strategies were also discussed. Proposed alternative strategies related to selective breeding for traits that can be utilized to manage diseases and scarcity in feed resources in IC production systems were presented in this chapter. Finally, the chapter gave a justification for this study, and objective and outline of the thesis. Literature estimates of genetic parameters are considered resourceful in instances where estimates for traits of interest are not available or insufficient. Estimates obtained from different studies, however, may vary due to differences in population among other factors. The choice of which estimate from sampled studies to use, is in most cases subjective and this may lead to either underestimation or overestimation of potential genetic progress. Chapter 2 assessed the robustness of literature estimates of genetic parameters for traits of economic importance in chicken performing in the tropical and sub-tropical environments using meta-analysis. Additive genetic, maternal environment and residual variances, and heritability estimates for traits related to immunity, reproduction, survival, growth, egg production and feed efficiency from 70 studies were considered. Heterogeneity index showed that published estimates of the genetic parameters sampled from different studies significantly varied in each of the traits. Based on total variance, a higher proportion of the variation in genetic parameters were more due to random effect of study than sampling error. Reliability estimates (relative standard error) of the genetic parameters varied across the traits considered in this study, in which, traits well represented in terms of number of published estimated had lower levels of variation compared to traits with low published estimated. Study characteristics related to population, production system, estimation methods, sex, age and antigen (only for immune traits) significantly influenced variation in the sampled genetic parameters across the traits. Pooled genetic parameters estimated in this study using the inverse of sampling variance as a weighting factor indicate that the weighted averages of genetic parameters can be utilized where estimates are not available or insufficient. The significant variation among sampled studies and low reliability estimated in some of the traits imply that genetic parameter estimates from literature should be applied with caution to prevent negative impacts on breeding decisions and genetic progress. In addition, differences in study characteristics should be considered in order to use estimates from studies with population and production conditions characteristics that closely resemble the intended population and production system. Antibody response to challenging conditions is suggested a suitable indicator trait that can be utilized for indirect improvement of disease resistance. However, prior to selection, understanding the genetic background of antibody response in the population of interest is a prerequisite in setting up an effective selection strategy. Chapter 3 investigated non-genetic and genetic sources of variation in natural antibodies binding to keyhole limpet hemocyanin antigen (KLH-NAbs) and specific antibodies binding to NCD virus (NDV-IgG). Non-genetic factors related to sex, population, phylogenetic cluster, generation, line, genotype and age significantly influenced the antibody traits, and should therefore be accounted for in genetic evaluations to reduce bias and improve accuracy of selection. Considerable amount of additive genetic variation was observed in the KLH-NAbs and NDV-IgG traits, implying possibilities of improvement of the antibody traits through selective breeding. However, the low to moderate heritability estimated in the antibody traits indicate that relatively low accuracy levels would be expected and hence, reduced rate of genetic gains if mass selection would be used. Positive genetic correlations observed among KLH-NAb isotypes (KLH-IgM, KLH-IgG and KLH-IgA) suggest that the isotypes can be improved simultaneously. In contrast, KLH-NAbs were negatively correlated with NDV-IgG implying that genetic improvement of natural antibodies would be associated with low specific antibodies binding NDV. These findings provide a better understanding of factors affecting antibody traits in a heterogeneous chicken population and may enable effective decisions prior to inclusion of immune parameters in breeding programs intended for tropically adapted chicken. Considering that an effective immune system is heavily dependent on metabolic resources for maintenance and deployment of various immune responses, improved antibody levels is expected to compete for nutrients and energy with other functions, such as production. Besides, given the scarcity in feed resources in production systems in Kenya, competition for nutrients and energy among biological functions is likely to influence the efficiency of feed utilization. Therefore, it is pertinent to also determine the pleiotropic nature between the immunity, production and feed efficiency traits. Chapter 4 estimated genetic and phenotypic correlations among antibody, feed efficiency and production traits measured pre- (nine to 20 weeks of age) and post- (12 weeks from on-set of lay) maturity. Results revealed 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. Negative genetic correlations estimated between feed efficiency and antibody 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 IC improvement programs. Based on marketable end products, a breeding goal targeting simultaneous improvement of meat and egg production to develop a dual-purpose (ICD) breed that can perform in low to medium input systems is recommended for the IC population. However, due to the dynamics in market forces over time, goals targeting specialized production to develop a meat (ICM) and a layer (ICL) breed that can perform in medium to high input systems are also recommended as alternatives. Prior to defining the selection criteria across the goals, it is necessary to determine optimal combination of traits in an index because this has an impact on the overall genetic merit of an individual and total index response. Chapter 5 evaluated various selection strategies for adoption in ICD and ICL and ICM goals in indigenous chicken breeding with respect to total index response, accuracy of selection, rate of inbreeding and number of generations of selection required to achieve pre-defined genetic gains. Selection strategy targeting only production traits in a goal had the highest total index response, highest index accuracy (only ICM goal) and lowest inbreeding rate per generation, and least number of generations of selection required to achieve pre-defined gains. The index was, however, associated with unfavorable correlated responses in feed efficiency and antibody traits. Addition of both feed efficiency and antibody response in a goal indicated favorable genetic gains could be achieved in these traits. Conversely, this strategy reduced total index response and increased the rate of inbreeding per generation and required additional number of generations of selection to achieve desired gains pre-defined in each of the goals. Inclusion of either feed-related traits or antibody traits in a goal showed that feed-related traits had a more negative impact on the total index response per generation but improved selection accuracy in the ICD and ICL goals compared to antibody traits. Based on these results, choice of whether to include feed efficiency or/and antibody response in the ICD, ICM and ICL goals should depend on targeted production system, resource availability to support additional number of generations of selection and magnitude of correlated responses on these traits when not included in the goals. Lastly, a synthesis of the thesis is presented in Chapter 6 where practical relevance and utilization of findings of the thesis in designing a breeding program for indigenous chicken population is demonstrated.
Haemotrophic mycoplasmas infecting pigs: a review of the current knowledge
(2024) Ade, Julia; Eddicks, Matthias; Ritzmann, Mathias; Hoelzle, Katharina; Hoelzle, Ludwig E.; Stadler, Julia; Ade, Julia; Department of Livestock Infectiology and Environmental Hygiene, Institute of Animal Science, University of Hohenheim, 70593 Stuttgart, Germany; Eddicks, Matthias; Clinic for Swine, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, 85764 Oberschleissheim, Germany; Ritzmann, Mathias; Clinic for Swine, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, 85764 Oberschleissheim, Germany; Hoelzle, Katharina; Department of Livestock Infectiology and Environmental Hygiene, Institute of Animal Science, University of Hohenheim, 70593 Stuttgart, Germany; Hoelzle, Ludwig E.; Department of Livestock Infectiology and Environmental Hygiene, Institute of Animal Science, University of Hohenheim, 70593 Stuttgart, Germany; Stadler, Julia; Clinic for Swine, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, 85764 Oberschleissheim, Germany; Highland, Margaret A.
Haemotrophic mycoplasmas (haemoplasmas) are a group of highly specific and adapted bacteria. Three different haemoplasma species in pigs are known to date: Mycoplasma ( M .) suis , M. parvum and ‘ Candidatus ( Ca .) M. haemosuis’. Even though these bacteria have been known in pig farming for a long time, it is difficult to draw general conclusions about the relevance of their infections in pigs. This review summarizes the current knowledge on the three porcine haemoplasma species with regards to clinical and pathological descriptions, pathobiology, epidemiology and diagnostics as well as prevention and therapy. Overall, it is clear that considerably more data are available for M. suis than for the other two species, but generally, porcine haemoplasmas were found to be highly prevalent all over the world. Mycoplasma suis is the most virulent species, causing acute infectious anaemia in pigs (IAP), whereas M. parvum usually results in chronic and subclinical infections associated with performance losses. Little is known about the clinical significance of the recently discovered third porcine species ‘ Ca . M. haemosuis’. So far, the described pathogenic mechanisms mainly include direct destruction of erythrocytes via adhesion, invasion, eryptosis and nutrient scavenging, indirect erythrocyte lysis due to immune-mediated events and immune dysregulation processes. A review of published diagnostic data confirms PCR assays as the current standard method, with various cross-species and species-specific protocols. Overall, there is a need for further examination to obtain valuable insights for practical application, specifically regarding the importance of subclinical infections in naturally infected animals. An essential requirement for this will be to gain a more comprehensive understanding of the mechanisms operating between the host and the pathogen.
Hemotrophic mycoplasmas - vector transmission in livestock
(2024) Arendt, Mareike; Stadler, Julia; Ritzmann, Mathias; Ade, Julia; Hoelzle, Katharina; Hoelzle, Ludwig E.; Arendt, Mareike; Department of Livestock Infectiology and Environmental Hygiene, Institute of Animal Science, University of Hohenheim, 70593 Stuttgart, Germany; (M.A.); (J.A.); (K.H.); Stadler, Julia; Clinic for Swine, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, 85764 Oberschleissheim, Germany; (J.S.); (M.R.); Ritzmann, Mathias; Clinic for Swine, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, 85764 Oberschleissheim, Germany; (J.S.); (M.R.); Ade, Julia; Department of Livestock Infectiology and Environmental Hygiene, Institute of Animal Science, University of Hohenheim, 70593 Stuttgart, Germany; (M.A.); (J.A.); (K.H.); Hoelzle, Katharina; Department of Livestock Infectiology and Environmental Hygiene, Institute of Animal Science, University of Hohenheim, 70593 Stuttgart, Germany; (M.A.); (J.A.); (K.H.); Hoelzle, Ludwig E.; Department of Livestock Infectiology and Environmental Hygiene, Institute of Animal Science, University of Hohenheim, 70593 Stuttgart, Germany; (M.A.); (J.A.); (K.H.); Dozois, Charles M.
Hemotrophic mycoplasmas (HMs) are highly host-adapted and specialized pathogens infecting a wide range of mammals including farm animals, i.e., pigs, cattle, sheep, and goats. Although HMs have been known for over 90 years, we still do not know much about the natural transmission routes within herds. Recently, it has been repeatedly discussed in publications that arthropod vectors may play a role in the transmission of HMs from animal to animal. This is mainly since several HM species could be detected in different potential arthropod vectors by PCR. This review summarizes the available literature about the transmission of bovine, porcine, ovine, and caprine HM species by different hematophagous arthropod vectors. Since most studies are only based on the detection of HMs in potential vectors, there are rare data about the actual vector competence of arthropods. Furthermore, there is a need for additional studies to investigate, whether there are biological vectors in which HMs can multiply and be delivered to new hosts.

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