Thomas Amon

• Leibniz Institute for Agricultural Engineering and Bioeconomy

Anaerobic digestion (AD) is a suitable process to use manure for biogas production. During this process, antimicrobial resistant (AMR) bacteria are reduced. In this study, we investigated the reduction of extended-spectrum beta-lactamase (ESBL)-producing, fluoroquinolone-resistant, and total Escherichia (E.) coli concentrations in chicken manure du...

Objective Mastitis is the most common and costly dairy cow disease worldwide. We performed an intensive analysis of mastitis prevalence, pathogens, and treatments using retrospective data from a commercial dairy farm in Germany to estimate the severity of mastitis in the commercial production system and to give on-farm insights. Material and Metho...

Naturally ventilated pig barns equipped with outdoor exercise yards (NVPBOYs) have the potential to alleviate issues related to poor animal well-being and excessive gaseous emissions compared with conventional intensive pig farming. However, as a novel pig housing system, the information on the ventilation process of NVPBOYs with respect to variabl...

Missing data and class imbalance hinder the accurate prediction of rare events such as dairy mastitis. Resampling and imputation are employed to handle these problems. These methods are often used arbitrarily, despite their profound impact on prediction due to changes caused to the data structure. We hypothesize that their use affects the performan...

Missing data and class imbalance represent a hindrance to accurate prediction of rare events such as mastitis (udder inflammation). Various methods are susceptible to handle the problem, however, little is known about their individual and combined effects on the performance of ML models fitted to AMS (automated milking system) data for mastitis pre...

Animal welfare strongly influences the health and performance of cattle and is an important factor for consumer acceptance. One parameter for the quantification of health status is the lying duration, which can be deployed for the early detection of possible production-related illnesses. Usually, 3D-accelerometers are the tool to detect lying durat...

The spread of antimicrobial resistance (AMR) in animal husbandry is usually attributed to the use of antibiotics and poor hygiene and biosecurity. We therefore conducted experimental trials to improve hygiene management in weaned pig houses and assessed the impact on the spread. For each of the two groups examined, the experimental group (EG) and t...

A barn’s climate is vital for animal welfare and emissions control, including greenhouse gases like methane (CH4) and carbon dioxide (CO2) and environmental gases like ammonia (NH3). The goal of this study was to investigate a developed low-cost online tool for monitoring barn climate and air pollutant emissions (OTICE) in naturally ventilated barn...

Ammonia emission rates from naturally ventilated livestock housing systems can be estimated in multiple ways. By coupling different modeling approaches towards a semi-mechanistic barn-scale ammonia emission model, we investigated the influence of urine puddle pH dynamics on the (sub)daily and seasonal pattern of ammonia emissions. We compared the s...

In natural ventilation system-enabled dairy buildings (NVDB), achieving accurate gas emission values is highly complicated. The external weather affects measurements of the gas concentration of pollutants (cP) and volume flow rate (Q) due to the open-sided design. Previous research shows that increasing the number of sensors at the side opening is...

Biogas production is a suitable option for producing energy from dairy and pig manure types. During manure storage, organic matter degradation results in methane emissions decreasing the potential biogas yield. The present research advances the understanding of the biochemical methane potential (BMP) and the chemical characteristics of manure colle...

In the assessment of pulmonary function in health and disease, both respiration rate (RR) and tidal volume (Vt) are fundamental parameters of spontaneous breathing. The aim of this study was to evaluate whether an RR sensor, which was previously developed for cattle, is suitable for additional measurements of Vt in calves. This new method would off...

The quantification of gas emissions from livestock housings is a complex and challenging measurement task because performing emission measurements under practice conditions requires a high level of expertise and poses significant challenges to obtaining a careful evaluation and a reliable validation. Many measurement methods have been developed in...

The regular use of antimicrobials in livestock production selects for antimicrobial resistance. The potential impact of this practice on human health needs to be studied in more detail, including the role of the environment for the persistence and transmission of antimicrobial-resistant bacteria. During an investigation of a pig farm and its surrou...

Accurate internal air distribution prediction facilitates the analysis of occupant thermal comfort and the control of gaseous contaminants within naturally ventilated livestock buildings (NVLB). However, the dynamic and random change in external wind conditions makes it difficult to predict the air distribution. This study compares three scenarios...

Livestock production contributes to releasing methane into the atmosphere. Liquid manure management offers significant opportunities to reduce these emissions. A better understanding of the factors controlling methane emissions from manure is necessary to select effective mitigation strategies. Our study aimed to identify the influence of storage t...

One way to estimate ammonia emission rates from naturally ventilated housing systems is to scale-up mechanistic modeling results. However, obtaining the relevant data to set initial and boundary conditions adequately is usually very challenging and for a whole barn barely possible. This study has investigated the potential of coupling different mec...

A versatile meteorological index for predicting heat stress in dairy cattle remains elusive. Despite numerous attempts at developing such indices and widespread use of some, there is growing skepticism about the accuracy and adequacy of the existing indices as well as the general statistical approach used to develop them. At the same time, precisio...

An increasing number of large pig farms are being built in multi-floor pig buildings (MFPBs) in China. Currently, the ventilation system of MFPB varies greatly and lacks common standards. This work aims to compare the ventilation performance of three popular MFPB types with different placement of fans using the Computational Fluid Dynamics (CFD) te...

Preventing and alleviating heat stress remain an enormous challenge in dairy farming. Although enhanced air distribution techniques have been developed and deployed in many barns, ventilation alone is no longer sufficient even in regions with historically mild climates. There is an increasing need for cooling of the intake fresh air. Evaporative co...

The focus of this study was to identify the effects of increasing ambient temperature (T) at different relative humidity (RH) and air velocity (AV) levels on heat loss from the skin surface and through respiration of dairy cows. Twenty Holstein dairy cows with an average parity of 2.0 ± 0.7 and body weight of 687 ± 46 kg participated in the study....

Ammonia and greenhouse gases have a negative impact on the environment. The most important agricultural sources of ammonia are dairy cattle housing systems, which are mainly naturally ventilated. Estimating emissions for naturally ventilated barns (NVB) is challenging due to the large number of influencing factors. Most notably, the direct coupling...

Methane (CH4) emissions from dairy husbandry are a hot topic in the context of active climate protection, where housing systems with slatted floors and slurry storage inside are in general expected to emit more than systems with solid floors. There are multiple factors, including climate conditions, that modulate the emission pattern. In this study...

Wind erosion is known to be a gradual process of soil degradation on arable lands. Poultry manure fertilization is a common practice to improve physical, chemical and biological soil properties, and is thus an essential part to maintain soil fertility. Shortly after incorporation, poultry manure and soil particles are loosely adjacent without any b...

Content NIR Sensors Challenges and potential of NIR sensors to simplify the generation of nitrogen flow balances – Digital mapping of nitrogen cycles ..... 1 On Farm Validation of different NIR Sensors for Manure Sensing ..... 9 Combine Harvester Analysis of Combine Harvester Threshing Systems Across Different Climate Regions ..... 17 An interactiv...

Content NIR Sensors Challenges and potential of NIR sensors to simplify the generation of nitrogen flow balances – Digital mapping of nitrogen cycles ..... 1 On Farm Validation of different NIR Sensors for Manure Sensing ..... 9 Combine Harvester Analysis of Combine Harvester Threshing Systems Across Different Climate Regions ..... 17 An interactiv...

Content NIR Sensors Challenges and potential of NIR sensors to simplify the generation of nitrogen flow balances – Digital mapping of nitrogen cycles ..... 1 On Farm Validation of different NIR Sensors for Manure Sensing ..... 9 Combine Harvester Analysis of Combine Harvester Threshing Systems Across Different Climate Regions ..... 17 An interactiv...

Content NIR Sensors Challenges and potential of NIR sensors to simplify the generation of nitrogen flow balances – Digital mapping of nitrogen cycles ..... 1 On Farm Validation of different NIR Sensors for Manure Sensing ..... 9 Combine Harvester Analysis of Combine Harvester Threshing Systems Across Different Climate Regions ..... 17 An interactiv...

Content NIR Sensors Challenges and potential of NIR sensors to simplify the generation of nitrogen flow balances – Digital mapping of nitrogen cycles ..... 1 On Farm Validation of different NIR Sensors for Manure Sensing ..... 9 Combine Harvester Analysis of Combine Harvester Threshing Systems Across Different Climate Regions ..... 17 An interactiv...

Content NIR Sensors Challenges and potential of NIR sensors to simplify the generation of nitrogen flow balances – Digital mapping of nitrogen cycles ..... 1 On Farm Validation of different NIR Sensors for Manure Sensing ..... 9 Combine Harvester Analysis of Combine Harvester Threshing Systems Across Different Climate Regions ..... 17 An interactiv...

Content NIR Sensors Challenges and potential of NIR sensors to simplify the generation of nitrogen flow balances – Digital mapping of nitrogen cycles ..... 1 On Farm Validation of different NIR Sensors for Manure Sensing ..... 9 Combine Harvester Analysis of Combine Harvester Threshing Systems Across Different Climate Regions ..... 17 An interactiv...

Content NIR Sensors Challenges and potential of NIR sensors to simplify the generation of nitrogen flow balances – Digital mapping of nitrogen cycles ..... 1 On Farm Validation of different NIR Sensors for Manure Sensing ..... 9 Combine Harvester Analysis of Combine Harvester Threshing Systems Across Different Climate Regions ..... 17 An interactiv...

Content NIR Sensors Challenges and potential of NIR sensors to simplify the generation of nitrogen flow balances – Digital mapping of nitrogen cycles ..... 1 On Farm Validation of different NIR Sensors for Manure Sensing ..... 9 Combine Harvester Analysis of Combine Harvester Threshing Systems Across Different Climate Regions ..... 17 An interactiv...

Agriculture is a major emitter of particulate matter (PM), which causes health problems and can act as a carrier of the pathogen material that spreads diseases. The aim of this study was to investigate an open-source solver that simulates the transport and dispersion of PM for typical agricultural applications. We investigated a coupled Eulerian–La...

With an increasing number of naturally ventilated dairy barns (NVDBs), the emission of ammonia and greenhouse gases into the surrounding environment is expected to increase as well. It is very challenging to accurately determine the amount of gases released from a NVDB on-farm. Moreover, control options for the micro-climate to increase animal welf...

The Streptococcus genus belongs to one of the major pathogen groups inducing bovine mastitis. In the dairy industry, mastitis is the most common and costly disease. It not only negatively impacts economic profit due to milk losses and therapy costs, but it is an important animal health and welfare issue as well. This review describes a classificati...

The tracer gas method is one of the common ways to evaluate the air exchange rate in a naturally ventilated barn. One crucial condition for the accuracy of the method is that both considered gases (pollutant and tracer) are perfectly mixed at the points where the measurements are done. In the present study, by means of computational fluids dynamics...

During a field experiment applying broiler manure for fertilization of agricultural land, we detected viable Clostridioides (also known as Clostridium) difficile in broiler feces, manure, dust, and fertilized soil. A large diversity of toxigenic C. difficile isolates was recovered, including PCR ribotypes common from human disease. Genomic relatedn...

Ammonia emissions damage the environment and have negative consequences for human and animal health. In the German livestock sector, most ammonia emissions come from naturally ventilated dairy barns. To reduce emissions, Germany has signed the EU Directive 2016/2284 to achieve a stepwise decrease in the ammonia emissions ceiling. The aim of this st...

ESBL‐/AmpC‐producing Escherichia coli from organic fertilizers were previously detected on soil surfaces of arable land and might be emitted by wind erosion. To investigate this potential environmental transmission path, we exposed ESBL‐/AmpC‐positive chicken litter, incorporated in agricultural soils, to different wind velocities in a wind tunnel...

Limited available land for livestock farming and increasing land-use costs have forced some large animal feeding operations to build animal barns from conventional one-floor to multi-floor in China recently because multi-floor animal building (MFAB) has a great advantage in saving land utilization. The ventilation system is an important part of ani...

Along with industry and transportation, agriculture is one of the main sources of primary particulate matter (PM) emissions worldwide. Bioaerosol formations and PM release during livestock manure field application and the associated threats to environmental and human health are rarely investigated. In the temperate climate zone, field fertilization...

Methane emissions from livestock manure are primary contributors to GHG emissions from agriculture and options for their mitigation must be found. This paper presents the results of a study on methane emissions from stored liquid dairy cow manure during summer and winter storage periods. Manure from the summer and winter season was stored under con...

The airflow in dairy barns is affected by many factors, such as the barn’s geometry, weather conditions, configurations of the openings, cows acting as heat sources, flow obstacles, etc. Computational fluids dynamics (CFD) has the advantages of providing detailed airflow information and allowing fully-controlled boundary conditions, and therefore i...

During a field experiment applying broiler manure for fertilization of agricultural land, we detected viable Clostridioides (formerly, Clostridium) difficile in broiler feces, manure, dust, and fertilized soil. A large diversity of toxigenic C. difficile isolates was recovered, including PCR ribotypes common from human disease. Genomic relatedness...

Dairy cows show a high sensitivity to changes in barn climate, which can result in physiological and ethological responses because of the homeostatic mechanisms to regulate the body temperature under heat load. The objective of this study was to analyze the lying behavior and occupancy of lying cubicles of lactating high-yielding Holstein-Friesian...

Technological progress enables individual cow's temperatures to be measured in real time, using a bolus sensor inserted into the rumen (reticulorumen). However, current cooling systems often work at a constant schedule based on the ambient temperature and not on monitoring the animal itself. This study hypothesized that tailoring the cooling manage...

The direct measurement of emissions from naturally ventilated dairy barns is challenging due to their large openings and the turbulent and unsteady airflow at the inlets and outlets. The aim of this study was to quantify the impacts of the number and positions of sensors on the estimation of volume flow rate and emissions. High resolution measureme...

A reliable quantification of greenhouse gas emissions is a basis for the development of adequate mitigation measures. Protocols for emission measurements and data analysis approaches to extrapolate to accurate annual emission values are a substantial prerequisite in this context. We systematically analyzed the benefit of supervised machine learning...

Livestock manure is recycled to agricultural land as organic fertilizer. Due to the extensive usage of antibiotics in conventional animal farming, antibiotic-resistant bacteria are highly prevalent in feces and manure. The spread of wind-driven particulate matter (PM) with potentially associated harmful bacteria through manure application may pose...

The air change rate (ACR) of naturally ventilated dairy buildings (NVDBs) plays an important part in the design and control of the ventilation system, as well as in the estimation of the gaseous emission rate. The objectives of this research were to model the ACR based on a quantitative investigation of the relationship between the ACR and its pote...

Airflow inside naturally ventilated dairy (NVD) buildings is highly variable and difficult to understand due to the lack of precious measuring techniques with the existing methods. Computational fluid dynamics (CFD) was applied to investigate the effect of different seasonal opening combinations of an NVD building on airflow patterns and airflow ra...

Emissions and ventilation rates (VRs) in naturally ventilated dairy barns (NVDBs) are usually measured using indirect methods, where the choice of inside and outside sampling locations (i.e. sampling strategy) is crucial. The goal of this study was to quantify the influence of the sampling strategy on the estimation of emissions and VRs. We equippe...

Two transient open source solvers, OpenFOAM and ParMooN, and the commercial solver Ansys Fluent are assessed with respect to the simulation of the turbulent air flow inside and around a dairy barn. For this purpose, data were obtained in an experimental campaign at a 1:100 scaled wind tunnel model. All solvers used different meshes, discretization...

This is the first study to quantify the dependence on wind velocity of airborne bacterial emission fluxes from soil. It demonstrates that manure bacteria get aerosolized from fertilized soil more easily than soil bacteria, and it applies bacterial genomic sequencing for the first time to trace environmental faecal contamination back to its source i...

The application of naturally ventilated pig buildings (NVPBs) with outdoor exercise yards is on the rise mainly due to animal welfare considerations, while the issue of emissions from the buildings to the surrounding environment is important. Since air pollutants are mainly transported by airflow, the knowledge on the airflow characteristics downwi...

The application of naturally ventilated pig buildings (NVPBs) with outdoor exercise yards is on the rise mainly due to animal welfare considerations, while the issue of emissions from the buildings to the surrounding environment is important. Since air pollutants are mainly transported by airflow, the knowledge on the airflow characteristics downwi...

Particulate matter (PM), emitted during agricultural activities, could be a source for the atmospheric dispersal of pathogenic or antibiotic resistant bacteria when agricultural fields are fertilized with contaminated manure. The use of contaminated bedding material from chicken breeding as farmyard manure can initiate a releasing process for resis...

The mandate to limit global temperature rise calls for a reliable quantification of gaseous pollutant emissions as a basis for effective mitigation. Methane emissions from ruminant fermentation are of particular relevance in the context of greenhouse gas mitigation. The emission dynamics are so far insufficiently understood. We analyzed hourly meth...

Antibiotic-resistant bacteria are a threat to human and animal health. In recent years, the presence of extended-spectrum-β-lactamase (ESBL)-producing Escherichia (E.) coli in chicken manure, which is used as organic fertilizer, is a concern. The aim of the present study was to determine the effects of the carbon/nitrogen (C/N) ratio and moisture c...

The discharge coefficient (Cd) is a characteristic parameter of an opening, which represents the effect of flow contraction and frictional losses when the flow goes across the opening. It is an important parameter for the ventilation rate determination when using the orifice equation method. The objectives of this study were to investigate the rela...

Environmental protection efforts can only be effective in the long term with a reliable quantification of pollutant gas emissions as a first step to mitigation. Measurement and analysis strategies must permit the accurate extrapolation of emission values. We systematically analyzed the added value of applying modern machine learning methods in the...

In the last decades, a global warming trend was observed. Along with the temperature increase, modifications in the humidity and wind regime amplify the regional and local impacts on livestock husbandry. Direct impacts include the occurrence of climatic stress conditions. In Europe, cows are economically highly relevant and are mainly kept in natur...

The dairy industry in regions with moderate climates, such as Central Europe, will be increasingly challenged in the future by climate change. The problem of heat stress will especially affect dairy husbandry in naturally ventilated barns (NVB). The approach of the study was to determine a heat stress threshold of the average daily temperature-humi...

The objective of this study was to provide a review of animal-related factors indicative of heat stress in dairy cows. To date, the temperature humidity index (THI) is a common method of evaluating the risk of heat stress in cows by employing climatic parameters. However, the THI is a general and indirect indicator that fails to consider individual...

The Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB) works on a range of interdisciplinary and transdisciplinary basic and applied research projects which deal with emissions, animal welfare and veterinary issues. Through activate participation in Food and Agriculture Organization (FAO) of the United Nations, The Intergovernmenta...

Climate change affects the frequency and intensity of extreme weather, the results of which include production losses and climate-induced crop productivity fluctuations. Double-cropping systems (DCSs) have been suggested as a way to increase biomass-production while simultaneously delivering environmental benefits. In a three-year field-test, two...

Air flow assessment in animal husbandry is an important issue in the context of welfare and emission. The aim of this study was to implement a porous medium approach for the numerical simulation of air flow in the animal occupied zone (AOZ) of a dairy building. Computational fluid dynamics (CFD) was used to determine the flow resistance properties,...

In the last decades, an exceptional global warming trend was observed. Along with the temperature increase, modifications in the humidity and wind regime amplify the regional and local impacts on livestock husbandry. Direct impacts include the occurrence of climatic stress conditions. In Europe, cows are economically highly relevant and are mainly...

The discharge coefficient (Cd) of an opening is an important parameter in the application of the orifice equation to calculate the airflow rate of naturally-ventilated buildings. It is questionable to regard Cd as a constant under varied external airflows for large openings that are often applied in dairy buildings. This study investigated the impa...

The main objective of this study was to identify the influences of different climatic conditions and cow-related factors on the respiration rate (RR) of lactating dairy cows. Measurements were performed on 84 lactating Holstein Friesian dairy cows (first to eighth lactation) in Brandenburg, Germany. The RR was measured hourly or twice a day with up...

The high prevalence of extended-spectrum-ß-lactamase (ESBL)-/AmpC-producing Escherichia (E.) coli in European broiler farms leads to the possible dissemination of antibiotic-resistant strains into the environment using contaminated feces as organic fertilizer. The aim of the present study was to determine the influence of temperature on the reducti...

The biogas production potential of different mixtures of cow manure (CM) and three-phase olive mill solid waste (3POMSW) at 37°C was evaluated. Results showed that 3POMSW produced more methane yield than CM. In the anaerobic co-digestion (AcoD) methane yield increased with increasing of 3POMSW content, the maximum methane yield was observed at 3POM...

The measurement of the respiration rate (RR) in cattle is a valuable tool for monitoring health status. Thus, an RR sensor can be essential for stress detection, especially heat stress. Heat stress leads to a deviation of the normal RR and results in a decrease of milk production and fertility. Therefore, continuous monitoring of the RR can help ea...

Gaseous emissions from livestock buildings have been a research focus for many years. In particular, quantifying emissions from naturally ventilated buildings is not trivial because it requires accurately determining the air exchange rate (AER) and representative gaseous concentration values in the exhaust and in the incoming air. Improvements are...

In recent years, the problem of the welfare and heat load of dairy cows has become increasingly important in moderate climate zones. The objective of the present study was to determine heat load thresholds of average daily temperature-humidity index (THI) that lead to changes in different activity traits of lactating high-yielding dairy cows. Furth...

To provide good indoor air quality for livestock, and quantify emission of ammonia and greenhouse gases, it is essential to understand indoor air characteristics with respect to ventilation openings in naturally ventilated livestock buildings. The objectives of this study were to investigate the influence of the sidewall opening size and location o...

Well-understanding indoor air movement with respect to openings in naturally-ventilated buildings is essential to provide healthy and comfortable indoor climate for livestock. This study investigated the effects of the sidewall opening configurations on internal airflow fields and air velocity characteristics within the animal occupied zone (AOZ)....

It is important to estimate the ventilation rate of animal houses accurately for the purpose of reducing emissions and providing comfortable indoor climate. The orifice equation is widely applied for estimating the airflow rate of naturally ventilated dairy barns. However, to regard openings’ discharge coefficient (Cd) as a constant maybe not true...

The microclimatic conditions in dairy buildings affect animal welfare and gaseous emissions. Measurements are highly variable due to the inhomogeneous distribution of heat and humidity sources (related to farm management) and the turbulent inflow (associated with meteorologic boundary conditions). The selection of the measurement strategy (number a...

The experiments comprised three vegetation periods of five sorghum varieties. Novel data on the development of biomass yield, maturity level and biogas production were gained. Dry matter (DM) biomass yield ranged between 15.7 and 20.67 t ha−1 when sorghum was grown as main crop. The variety SOR 4 achieved a methane yield of 6500 m3 ha−1. The suitab...