Institut für Tropische Agrarwissenschaften (Hans-Ruthenberg-Institut)

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Genetics and breeding for humoral immunity and feed efficiency in indigenous chicken population in Kenya
(2024) Miyumo, Sophie; Chagunda, Mizeck
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.
Etablierung und Vernetzung digital-gestützter Systeme auf Pferdebetrieben unter Berücksichtigung der betriebswirtschaftlichen Optimierung
(2024) Speidel, Linda Thurid; Dickhöfer, Uta
Das Management eines pferdehaltenden Betriebs umfasst eine Vielzahl arbeitswirtschaftlicher Herausforderungen. Dazu zählen unter anderem die zeitintensiven Arbeitsabläufe, das notwendige Kundenmanagement in Pensions- und Schulpferdebetrieben sowie die begrenzte Verfügbarkeit von Fachkräften. Auf Ackerbau- und Veredelungsbetrieben wird der Nutzen der Digitalisierung bereits wahrgenommen, da deren Einsatz unter anderem Potenzial zur Zeitersparnis und Arbeitserleichterung bietet. Obgleich des genannten Potenzials sind Pferdebetriebe bisher wenig digitalisiert und technisiert, die Grundversorgung erfolgt meist manuell. Im Rahmen dieser, im Projekt „Digitale Wertschöpfungsketten für eine nachhaltige kleinstrukturiert Landwirtschaft“ (DiWenkLa) angefertigten, Forschungsarbeit wurde daher untersucht, welche Möglichkeiten der Digitalisierung bisher genutzt werden und unter welchen Voraussetzungen die einzelnen Systeme in Pferdebetrieben etabliert werden können. Des Weiteren wurde analysiert, welche Auswirkungen der Einsatz dieser Systeme auf den Arbeitszeitbedarf im Pferdebetrieb hat und welche Informationen über Schnittstellen zwischen den Systemen ausgetauscht werden können. Dafür wurden von März 2020 bis Oktober 2023 Experteninterviews, (Arbeitszeit-)Beobachtungen und Online-Befragungen durchgeführt. Zunächst wurden die vorhandenen Möglichkeiten der digitalen Technisierung auf Pferdebetrieben in der Fütterung von Rau- und Krippenfutter, der Entmistung und Einstreu, der Gesundheits- und Sicherheitsüberwachung sowie der Kommunikation und dem Betriebsmanagement untersucht. Der Schwerpunkt lag auf den Voraussetzungen, die erfüllt sein müssen, um ausgewählte digital-technische Systeme auf den Betrieben zu etablieren. Zu diesem Zweck wurden Beobachtungen und Befragungen bei pferdehaltenden Betrieben (N=1235) und den Kooperationspartnern aus der Industrie des Projekts DiWenkLa durchgeführt. Die Ergebnisse zeigen, dass die Einbindung digital-technischer Systeme von der Investitionsbereitschaft der Betriebsleitenden, der stabilen Internetverbindung, einer verfügbaren Stromversorgung in den Stallgebäuden (Steckdosen) und dem vorhandenen Haltungssystem (z. B. Einzel- oder Gruppenhaltung sowie Gliederung der Haltung in Funktionsbereiche) abhängt. Auf den an einer Online-Befragung teilnehmenden Pferdebetrieben (N=451) wurden Kameras zur Sicherheits- (30,8 %) und Gesundheitsüberwachung (22,6 %) sowie Software für die Kundenkommunikation (24,8 %) und das Betriebsmanagement (13,7 %) eingesetzt. Die automatisierte Fütterung von Krippenfutter (9,3 %) und Raufutter (7,3 %) war selten vorhanden. Eine Gliederung der Haltung in Funktionsbereiche führte zu einem vermehrten Einsatz digital-technischer Systeme. Als Gründe gegen den Einsatz neuer digital-technischer Systeme wurden von den 207 teilnehmenden Betriebsleitenden die fehlenden Finanzmittel, der unbekannte wirtschaftliche Nutzen sowie der Kontaktverlust zu den Tieren genannt. In Anlehnung an die vorliegenden Ergebnisse erscheint eine erneute Erhebung der vorhandenen Systeme auf Pferdebetrieben sinnvoll, um etwaige Veränderungen im Verlauf der Zeit abzubilden und die Gründe für die Investition in neue digital-technische Systeme zu ermitteln. Des Weiteren sollte untersucht werden, ob Einsteller bei einem höheren Digitalisierungsgrad im Pferdebetrieb bereit sind, einen höheren Pensionspreis zu bezahlen. Zu diesem Zweck könnte die Zahlungsbereitschaft beim Einsatz von z. B. Futterautomation und intelligenten Kameras zur Gesundheitsüberwachung abgefragt werden. Des Weiteren wurde analysiert, welche betriebswirtschaftlichen Vorteile die auf den Pferdebetrieben etablierten, digital gesteuerten Systeme mit sich bringen können. Dazu wurden die möglichen Auswirkungen der Digitalisierung auf den Arbeitszeitbedarf für verschiedene Arbeitsabläufe wie die Fütterung, Entmistung und Hütesicherheit untersucht. Dies wurde durch Zeiterfassungen mit und ohne den Einsatz der Systeme sowie mit Hilfe von Online-Befragungen (N=1014) und Experteninterviews (N=16) realisiert. Die Ergebnisse der Untersuchungen zeigen bei der Einzelhaltung von Pferden eine potenzielle Arbeitszeitersparnis in der Fütterung und Entmistung von bis zu 65 % durch eine automatisierte Fütterung von Rau- und Krippenfutter und den Einsatz von mobiler Technik, wie beispielsweise einem Hoflader. Zudem kann der Einsatz dieser Systeme auch dazu führen, dass die benötigte Arbeitszeit in anderen Arbeitsabläufen sinkt. Ein Beispiel hierfür ist der Einsatz einer automatisierten Fütterung, welcher zu einer geringeren Arbeitszeit in der Kundenkommunikation führte. Dies wurde in den durchgeführten Datenerhebungen dadurch begründet, dass gewünschte Änderungen in der Rationsgestaltung automatisiert erfolgen und somit nicht persönlich kommuniziert werden müssen. Darüber hinaus lassen sich durch eine digitale Absprache und die Dokumentation wesentlicher Arbeitsschritte und Änderungen in den Abläufen sowie Kundenwünschen Fehler reduzieren und Missverständnisse vermeiden. Auf Basis der Ergebnisse sollten die Abfragen der Arbeitszeitbedarfe der Arbeitsabläufe mit exakten und vorgegebenen Werten wiederholt und teilweise ergänzt werden. Dies betrifft z. B. den Zeitbedarf für das Betriebsmanagement, die Tierkontrolle und den Weidegang. Dadurch können die vorhandenen Kalkulationsgrundlagen aktualisiert und das Bewusstsein der Betriebsleitenden für teils unbeachteten Arbeitszeitaufwand geschärft werden. Dieser kann wiederum durch den Einsatz von digital-technischen Systemen reduziert werden. Darüber hinaus wurde ein Konzept für eine Schnittstelle für digitale Systeme für Pferdebetriebe entwickelt, um den Datenaustausch zwischen Systemen zu vereinfachen und somit die Übersichtlichkeit der verschiedenen Informationen aus den eingesetzten Technologien zu optimieren sowie zusätzliche Zeitersparnis zu gewährleisten. Dazu wurden mittels Experteninterviews (N=20 Experten) die auszutauschenden Informationen zwischen Systemen für die Fütterung, die Entmistung und Einstreu, die Gesundheits- und Sicherheitsüberwachung sowie das Betriebsmanagement und die Kommunikation identifiziert, um eine verbesserte Übersicht für die Betriebsleitenden zu gewährleisten. In diesem Kontext wurde der Datenaustausch zwischen Futterautomationen und Kommunikationssoftware als besonders relevant hervorgehoben. Je nach Bedarf können die Informationen aus dem Datenaustausch transparent an die Kunden (z. B. Einsteller) weitergegeben werden. Eine Online-Befragung ergab, dass die Mehrheit (57,2 %) aller Teilnehmenden (N=451) Interesse an einer Vernetzung der Systeme zeigt. In zukünftigen Untersuchungen könnten zum einen die Gründe für das Interesse an einer Vernetzung analysiert werden, da bisher lediglich die Gegenposition untersucht wurde (d.h. Gründe gegen das Interesse an der Vernetzung). Zum anderen könnte die Einbindung weiterer Systeme neben den genannten geprüft werden, insbesondere die Anbindung der vorhandenen Hardware (z. B. Solarien, Aquatrainer) an das Internet und die (standardisierte) Programmierung der Schnittstelle, um z. B. eine unkomplizierte und transparente Abrechnung der Nutzung zu ermöglichen. Die Etablierung und Vernetzung digital-technischer Systeme in Pferdebetrieben ist bei erfüllbaren Voraussetzungen als sinnvoll anzusehen, da sie eine Arbeitszeiteinsparung generieren, eine Entlastung der Arbeitskräfte ermöglichen, die Kommunikation verbessern und das Betriebsmanagement sowie die Sicherheits- und Gesundheitskontrolle der Tiere vereinfachen. Diese Faktoren sind neben der Beachtung und Verbesserung des Tierwohls für eine nachhaltige, zukunftsfähige Pferdehaltung unabdingbar.
Rumen fermentation, microbial protein synthesis, and nitrogen balance in tropical cattle fed cultivated forages
(2024) Sainz-Sanchez, Pedro Alan; Dickhöfer, Uta
Over the past decade, extensive research has focused on the role of cultivated forages in cattle diets and their effects on animal performance, particularly in terms of milk yield and daily live weight gain. Despite this progress, there remains a scarcity of information regarding the dietary factors influencing the efficiency of ruminal microbial crude protein (MCP) synthesis and nitrogen (N) balance in tropical cattle fed on cultivated forages. In the Tropics and Subtropics, a variety of non-structural carbohydrate (NSC) sources are commonly used as energy supplements for tropical cattle. Current advancements in ruminant nutrition highlight the need for a deeper understanding of the complex interactions between the type of NSC, the kinetics of starch degradation, and the timing of supplementation, particularly in the context of high-quality forage diets. Hence, the overall objective of the thesis was to comprehensively understand the dietary factors influencing the rumen MCP synthesis and N balance in tropical cattle fed on high-quality and low-quality cultivated forages. This doctoral thesis hypothesized that the rumen MCP synthesis and the N balance in tropical cattle are mainly affected by the crude protein (CP) and fiber concentrations of cultivated forages. It was further hypothesized that dietary factors such as the supplementation of NSC, type of NSC, and time of supplementation influence the nutritional quality of cultivated forages and affect the rumen MCP synthesis and excretion in tropical cattle. Overall, one in vitro and two in vivo studies were conducted to investigate the proposed hypotheses. In the first in vivo study (Chapter 2), three forage grass species (Cenchrus purpureus, Chloris gayana, and Urochloa brizantha), grown alone or intercropped with a forage legume (Dolichos lablab), were evaluated to determine feed intake, digesta passage rates, rumen MCP synthesis, and N balance in Boran steers. The results showed similar duodenal MCP flow, MCP synthesis efficiency, and digesta passage rates in steers fed different forage grasses, whether grown alone or intercropped. Minor variations in dry matter (DM) intake largely drove increased N intake, fecal N excretion, and N balance, particularly when no significant differences in the chemical composition of the forage grass species were observed. The in vitro study (Chapter 3) evaluated the interactions between tropical forage grasses (Urochloa humidicola and Urochloa mutica) and forage legumes (Desmodium uncinatum, Stylosanthes guianensis, and Mucuna pruriens) and their effects on in vitro total gas production (TGP), short-chain fatty acids (SCFA) concentration and profile, and MCP synthesis. For this, various forage-legume mixtures were prepared by varying the ratios of forage legume to forage grass (75:25 or 25:75 on DM basis). Results indicated that in vitro TGP, short-chain fatty acids concentration and profile, and MCP synthesis were influenced by CP concentration, CP degradation extent, and the fermentation of both structural and NSC of the forages. Additionally, supplemental CP and NSC, influenced in vitro TGP and MCP synthesis. The second in vivo study (Chapter 4) evaluated the use of corn and oat, differing in extent and rate of ruminal starch degradation as NSC sources (i.e., corn- and oat-based concentrate mixtures), supplemented to lactating Brown Swiss cows before or after grazing on an alfalfa-ryegrass sward. The study measured feed intake, rumen MCP synthesis, nutrient digestibility, N partitioning, and milk performance. Supplementing corn-based concentrate mixture after grazing and oat-based concentrate mixture before grazing improved the efficiency of MCP synthesis, milk performance, and efficiency of N use in grazing lactating dairy cows. The effects of NSC supplementation were influenced by the interdependent interactions of starch concentrations of NSC sources, their ruminal degradation kinetics, and the timing of supplementation. The findings of the present thesis, supported by existing literature, demonstrate that cultivated tropical forages can provide sufficient N compounds to support rumen MCP synthesis, meeting the CP requirements of tropical cattle without negatively affecting DM intake, nutrient digestibility, N balance, or overall animal performance. Although CP concentration of the cultivated forages is a key factor influencing rumen MCP synthesis and N balance in tropical cattle, this perspective overlooks important aspects such as the distinction between rumen degraded protein and rumen undegraded protein which provide a clearer representation of CP degradation and utilization at both, the ruminal and post-ruminal levels. The CP concentration in cultivated tropical forages is not the only factor affecting N balance; other nutritional factors, such as energy concentration, neutral detergent fiber, and acid detergent fiber concentrations, also play a crucial role. Specifically, the energy concentration of the forage affects the capture of N by ruminal microbes, while the concentrations of neutral detergent fiber and acid detergent fiber influence the available energy in the forage, thereby impacting overall N utilization in tropical cattle. The interaction between the time of supplementation and the type of NSC source influences the synchronization of N and energy in the rumen. The response to NSC supplementation is influenced by the timing of supplementation and the degradation rates of CP and carbohydrates in both the forages and NSC sources. In the context of the results presented in the present thesis and the existing literature, cultivated tropical forages not only enhance protein nutrition and performance in tropical cattle but may also contribute positively to environmental sustainability. For instance, reducing urinary and fecal N excretion helps limit excessive N release into the environment. Additionally, intercropping forage legumes with grasses can enhance soil fertility and improve soil structure. However, further research is required to assess overall system sustainability and to develop comprehensive feeding strategies for tropical cattle in the Tropics and Subtropics.
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.
A collaborative, systems approach for the development of biomass-based value webs: The case of the acrocomia palm
(2022) Vargas-Carpintero, Ricardo; Hilger, Thomas; Tiede, Karen; Callenius, Carolin; Mössinger, Johannes; Souza, Roney Fraga; Barroso Armas, Juan Carlos; Rasche, Frank; Lewandowski, Iris
The diversification of biomass resources is key to the transition towards a bioeconomy. Acrocomia spp., a neotropical genus of palms, is an example of plants’ diversity potential for a sustainable bioeconomy. Acrocomia’s adaptability to environments outside rainforests, its specific fruit properties and high yields has generated the interest of researchers and entrepreneurs, triggering its introduction as a multipurpose oil crop. Developing sustainability-oriented and knowledge-based acrocomia value webs requires a collaborative, systems approach from the outset. Fostering an inter- and transdisciplinary dialogue on acrocomia through a participatory workshop with both academic and non-academic actors contributed to this endeavor. This allowed the identification of priorities, knowledge gaps, and stakeholder roles, and served as the basis for the co-creation of a research and development roadmap. Key steps for the introduction of acrocomia include intertwined technical aspects relating to the development of planting material, cultivation systems, processing technologies and applications, market entry, and value web governance aspects. A broad collaboration among scientists, the public and private sectors, farmers, and civil society, is required for the development of acrocomia value webs. The incorporation of sustainability and a consideration of context in the design and development phases are fundamental to fostering the sustainable performance of acrocomia value webs.

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