Measurement setup for investigating the aerobic stability of silage, and measurement method

Abstract

A measuring arrangement (100) for examining silage is described, comprising the measuring arrangement (100): i) a first sample container (110) which is equipped to receive a first silage sample (112); ii) a second sample container (120) which is designed to receive a second silage sample (122); and iii) a measuring lid (150) which is designed to cover the first sample container (110) or the second sample container (120), wherein the measuring cover (150) has a sensor device (155) which is configured: a) to determine a measurement relating to the first silage sample (112) while covering the first sample container (110), and / or b) to determine the measured value of the second silage sample (112) while covering the second sample container (120), where the measured quantity relates to a hydrogen and / or nitrogen-containing metabolic product.

Description

Technical area

[0001] The invention relates to a measuring arrangement for analyzing silage. In particular, two or more sample containers are loaded with silage samples, and at least one parameter relating to a microbial metabolite is analyzed using a sensor device on a measuring lid while the respective sample container is covered with the measuring lid. Furthermore, the invention relates to a method for analyzing silage.

[0002] Accordingly, the invention may lie in the technical field of measurement technology, in particular the examination of silage samples. Technical background

[0003] Silage is one of the most important feedstuffs in global animal nutrition, particularly for ruminants, e.g., dairy cattle and beef cattle. The preservation of corn and alfalfa, for example, is based on lactic acid fermentation and thus on the fermentation of carbohydrates in the harvested crop. During fermentation, the silage (or its starting product) is usually stored in a silo (anaerobically). Following the actual ensiling process, the silo is then opened and fed to animals, for example. During this phase, i.e., when the silo is open (and aerobic conditions prevail), various microorganisms such as yeasts, molds, etc. lead to degradation and spoilage of the silage. The feed quality decreases and negatively affects animal health and performance. As a result of these conversion processes, heat is produced and the silo heats up.

[0004] Through proper management, yeasts and molds can be specifically inhibited. This can be achieved, for example, with silage additives. These are chemical compounds such as organic acids or their salts, or microorganisms that produce specific metabolites. In both cases, the goal is for the end products to exhibit a specific inhibitory effect against microorganisms such as yeasts and fungi, thus improving the storage stability of the silage. Various commercial additives have been or are being developed to improve, for example, the antioxidant capacity of silage. The global market for silage additives was valued at USD 3.14 billion in 2021 and is expected to reach USD 4.34 billion by 2028.

[0005] The effectiveness of silage additives is conventionally tested by measuring silage temperatures over 7 to 14 days. If silage temperatures rise under constant storage conditions (depending on the test system, 2 or 3 K above the uniform room temperature), microbial activity and spoilage processes are assumed.

[0006] However, temperature measurement alone offers little insight into the (microbiological) processes actually occurring in the silage. Accordingly, conventional silage tests can be considered inaccurate and lacking in detail because they lack a comprehensive picture of silage oxidation. More precise conclusions about which microorganisms or degradation processes lead to silage spoilage are generally not possible. This limits the speed of new or further development of silage additives. Furthermore, the use of different sensors for different silage samples can lead to significant inherent measurement errors, which further reduce the significance of the measurement results.

[0007] The oxidation properties of silage not only affect the aerobic metabolic processes of the undesirable microorganisms. These degradation and conversion processes also lead to changes in biochemical characteristics. For example, the degradation of lactic acid by yeasts leads to a change in pH, which can improve the environmental conditions for other aerobic microorganisms. The current measurement method for characterizing aerobic spoilage in silage using a single parameter (silage temperature, Tsi) can lead to uncertain conclusions.

[0008] Silage additives are generally divided into two main categories: chemical and biological. The former usually consist of organic acids or their salts, while the latter usually contain various lactic acid bacteria to influence fermentation and the chemical composition of the silage. These effects on fermentation can then be beneficial for the aerobic stability of the silage. Each category of additive thus improves the antioxidant capacity of silage through different principles, so it can be difficult to explain the specific effectiveness of different additives based solely on silage temperature.

[0009] Lactic acid bacteria, for example, are generally divided into homofermentative and heterofermentative bacteria, and both bacteria coexist in silage. The latter can increase aerobic stability, for example, by producing acetic or propionic acid during the fermentation process. During the oxidation processes of silage, it can be difficult to interpret the individual expression and interaction of bacterial activity or their metabolites based on temperature alone.

[0010] Yeasts, for example, act as producers in silage under aerobic conditions, metabolizing carbohydrates into H2O, CO2, and heat. However, under anaerobic conditions, they become producers, partially metabolizing carbohydrates into ethanol rather than H2O. Without dynamic information about the silage, it can be difficult to fully understand the oxidation process based on temperature measurements alone.

[0011] Shan, Guilin et al.: Insight of CO2 and ethanol emission from maize silage: A case study with real-time identification of aerobic and anaerobic microbial respiration using a multi-sensor-fusion method. In: Environmental pollution, Vol. 335, 2023, Art. 122361 (6 pp.). This paper describes an investigation of the kinetics of CO2 and EtOH emissions from baled maize silage using real-time identification, quantification, and separation of aerobic and anaerobic respiratory components in the period after silage opening.

[0012] Shan, Guilin et al.: Multi-sensor measurement of O2, CO2 and reheating in triticale silage: An extended approach from aerobic stability to aerobic microbial respiration. In: Biosystems Engineering, Vol. 207, 2021, pp. 1–11. This paper concerns the biochemical reactions of aerobic microbial respiration (AMR), suggesting that the increase in silage temperature (Tsi), oxygen consumption (O2), and carbon dioxide emission (CO2) can be equally useful as indicators of silage deterioration during feeding, but so far, only temperature has been used to assess aerobic stability. Here, the study of aerobic stability is extended to include AMR of silage by developing a novel experimental cell integrated with multiple sensors.

[0013] CN 1 09 781 943 A relates to the field of gas emission detection and discloses a device for automatically detecting the amount of greenhouse gas emissions. The device comprises a box body, a box lid, a drive module, a gas detection module, and a control module, wherein greenhouse gas released by a detected object enters an internal cavity of the box body from a gas inlet end of the box body.

[0014] DE 20 2010 005 307 U1 relates to a device for measuring a gas volume of a substance, in particular measuring carbon dioxide during a processing process, for example a fermentation phase, consisting of a metal vessel, a measuring head and a sealing ring between the metal vessel and the measuring head as well as a clamping ring for clamping the metal vessel and the measuring head, wherein the measuring head has an absolute pressure sensor which can be coupled to an evaluation software via a digital converter and the sealing ring is gas-tight.

[0015] EP 3 919 901 A1 relates to a sensor for determining the freshness of a food placed in a container of a storage container. The sensor device comprises a gas sensor configured to acquire sensor data relating to the gas contained in the container. Furthermore, the sensor device comprises a user interface configured to enable a user to indicate the type of food placed in the container. Furthermore, the sensor device comprises a control unit configured to enable the determination of the freshness of the food based on the sensor data provided by the gas sensor and on the indication of the type of food provided by the user interface. Summary of the invention

[0016] There may therefore be a need to analyze silage in an efficient and reliable manner. A measurement setup and method are described below.

[0017] According to a first aspect of the invention, a measuring arrangement (or a test bench) for examining silage (samples) is described, the measuring arrangement comprising: i) a first sample container (e.g. a 1.5 litre standard container) which is designed to receive a first silage sample (which in particular has already undergone the silage process) (e.g. in a sample volume); ii) a second (or more) sample container (identical or different from the first sample container) arranged to receive a second silage sample (identical or different from the first silage sample); iii) a measuring cover (e.g. a cover-shaped structure with a sensor, a mobile gas detector) which is designed to (automatically) cover (in particular to seal gas-tight / hermetically) the first sample container or the second sample container, wherein the measuring cover comprises a sensor device (which comprises at least one sensor, e.g. an ethanol sensor) which is arranged: a) to determine a measured value (e.g. concentration, emission rate) relating to the first silage sample while covering the first sample container, and / or b) while covering the second sample container, to determine the measurand (or a second measurand; identical or different with respect to the first measurand) with respect to the second silage sample. The measurand concerns a hydrogen- and / or nitrogen-containing (microbiological) metabolic product (e.g., ethanol and / or ammonia); and iv) a movement device which is coupled (can be coupled) to the measuring cover and which is configured to move the measuring cover from the first sample container to the second sample container (or vice versa).

[0018] According to a second aspect of the invention, a method for examining silage is described, the method comprising: i) at least partially covering a first sample container containing a first silage sample (stored under aerobic conditions) by means of a measuring lid, ii) determining a measured value relating to the first silage sample by means of a sensor device arranged on the measuring cover; (and thereafter) (in particular moving the measuring lid to a second sample container or moving the second sample container to the measuring lid), iii) at least partially covering the second sample container containing a second silage sample by means of the measuring lid, and (thereafter) iv) Determining the measured variable with respect to the second silage sample by means of the sensor device.

[0019] The measured quantity refers to a hydrogen and / or nitrogen-containing (microbiological) metabolic product (e.g. ethanol).

[0020] In the context of this document, the term "silage" can specifically refer to a material suitable as animal feed and which has been treated by a fermentation process (so-called ensiling process). For example, silage can be animal feed preserved by lactic acid fermentation. Examples of ensiled materials include grass (grass silage), maize (maize silage), millet (sorghum), clover, alfalfa, field beans, cereals (as whole-crop silage), sugar beet pulp, and others. In principle, other (agricultural) substances can also be used and tested, e.g., solid or liquid manure, compound feed or mixed rations, but also non-agricultural goods. This may sometimes require a setup with upright sample containers.

[0021] In the context of this document, the term “sample container” can refer in particular to a container with a volume for holding a silage sample. This sample container can be filled with silage for the measuring process, but in one example is the silo itself, so that the material is sampled unchanged by the measuring process after the fermentation process. In one example, the sample container has the sample volume and is closed directly with the measuring lid. In another example, the sample container (e.g. as a sample glass) can be stored in a holding structure or inserted into it. For example, the holding structure can be designed as a tubular cylinder. In this example, the holding structure can be longer in the main direction of extension than the actual sample container, so that the measuring lid is placed on the holding structure and not directly on the actual sample container.In the present context, the actual sample container (with the sample volume) and the holding structure together can be understood as the sample container, so that the sample container is also covered by the measuring lid in this case.

[0022] In the context of the present document, the term "measuring cover" (or mobile gas detector) can refer in particular to a structure that is suitable for at least partially covering a sample container (e.g., cylindrical), or the sample volume of the sample container, or a holding structure for the sample container. Furthermore, the measuring cover can have at least one sensor device that is suitable for measuring at least one parameter. The measuring cover can be configured to be at least partially inserted into the sample volume. Furthermore, the measuring cover can also be configured to be partially pushed over the sample container / the holding structure. In a further example, the measuring cover can rest (planar) on the sample container / the holding structure. In a preferred example, the measuring cover forms a closed gas space when covering the sample container and / or covers a gas space. The measuring cover can, for example,made of plastic, ceramic, or a metal plate.

[0023] In the context of the present document, the term "sensor device" can refer in particular to one or more sensors. Furthermore, a sensor device can also have an evaluation unit for evaluating the measured data. In one embodiment, the sensor device is designed as an ethanol sensor, which protrudes through the actual measuring lid into the sample volume of a sample container. The sensor device can be provided on and / or in the measuring lid or extend through it. In a specific embodiment, the sensor device can have an ethanol sensor and / or a CO2 sensor. The use of further sensors is optionally possible, depending on the question to be investigated.

[0024] In the context of this document, the term "metabolite" can specifically refer to a chemical compound produced by microbiological metabolism. For example, yeasts can anaerobically metabolize sugar molecules (from silage) into carbon dioxide and ethanol. In this case, carbon dioxide would be an inorganic metabolite, while ethanol is an organic (hydrogen-containing) metabolite. This document follows the general chemical principle that carbon compounds in which there is no bond between carbon and hydrogen (e.g., carbon dioxide, carbon monoxide) are considered inorganic. In another example, metabolites can be methane (CH4) (containing hydrogen), nitrous oxide (containing hydrogen and nitrogen), ammonia (containing nitrogen), and / or other volatile organic compounds (VOCs; e.g.,volatile acids (e.g. acetic acid, propionic acid), alcohols (e.g. methanol, 1-propanol), aldehydes (e.g. acetaldehyde, butyralaldehyde), esters (e.g. propyl acetate, ethyl acetate, ethyl lactate), etc.) are produced.

[0025] In the context of this document, the term "measured variable" can refer in particular to a parameter that is measured or determined by the sensor device. This can be, for example, a concentration or volume of a (gas) emission. If the emission is determined over time, an emission rate or velocity can be determined, for example.

[0026] According to an exemplary embodiment, the invention may be based on the idea that silage can be examined in an efficient and reliable manner if a measuring arrangement is provided which comprises a plurality of sample containers (each containing silage samples) and a measuring lid with a built-in sensor, wherein the measuring lid successively covers each sample container and takes a measurement with respect to a microbial metabolite (organic and / or nitrogen compound) in each case.

[0027] While conventional methods (see above) only involve temperature measurements to characterize a silage sample, the inventors have recognized that a surprisingly efficient and reliable examination of the silage can be achieved by analyzing organic metabolites, in particular ethanol, from the microorganisms present in the silage. Temporal shifts in the emission rate of these metabolites (outgassing of existing metabolites or new formation during aerobic metabolism) also allow conclusions to be drawn about the composition of the microbiological community found in aerobic spoilage. For the precise measurement of, for example, ethanol streams from multiple silage samples, the invention uses one sensor device (in particular a mobile gas detector) instead of multiple gas sensors. This eliminates the inherent errors between multiple sensors, since one sensor measures all samples.The test results showed high reliability and low standard errors of the measured values ​​(see also . Fig. 4 and Fig. 5).

[0028] Microbially produced metabolites in particular can provide detailed insight into the complex (microbiological) silage system and thus be an important parameter for assessing microbial processes. In addition to hydrogen / nitrogen-containing metabolites, other parameters (inorganic metabolites, oxygen content, pH value, temperature, etc.) are preferably measured, and these have shown surprisingly significant mutual influences and dependencies in the causal chains of processes and results (see also Fig. 4, Fig. 5, and Fig. 6).

[0029] With the described method, practical samples (which have already undergone a silage process) can be examined, even in a standard-compliant manner.

[0030] Therefore, the chemical and physical parameters of silage during storage under aerobic conditions are primarily examined. The recorded parameters provide insights into spoilage processes in the silage, which can be caused by various microorganisms in their respiratory metabolism. This makes it possible to generate new insights into spoilage and the resulting climate- and environmentally relevant emissions, and to derive possible measures to improve storage stability. Exemplary implementation examples

[0031] According to one embodiment, the metabolite comprises ethanol and / or methane. According to a further embodiment, the metabolite comprises ammonia (NH3) and / or nitrous oxide (N2O). The metabolite can also comprise at least one further nitrogen oxide (NOx). This can have the advantage that metabolites frequently generated by microorganisms in silage can be directly determined. These measurements can also enable characterization of the complex silage system with regard to microorganisms and provide reliable information regarding oxidation behavior. Nitrous oxide and / or nitrogen oxides (especially NO2) can be relevant for occupational safety and silo fillers disease (i.e., nitric acid formation in the lungs).

[0032] According to one embodiment, the metabolite contains volatile organic compounds (VOCs) (volatile acids, alcohols, esters, aldehydes, etc.) (e.g., acetic acid, propionic acid, methanol, propanol, acetaldehyde, butyralaldehyde, propyl acetate, ethyl acetate, or ethyl lactate). VOCs can be relevant to the climate and environment, as well as important for animal nutrition. Consequently, scientific interest in them may grow in the future. Silage can emit over 40 different volatile organic compounds; these can include, for example, acetic acid, propionic acid, butyric acid; alcohols such as methanol, propanol, butanol, and hexanol; ketones such as acetone; esters (e.g., methyl acetate, methyl butyrate, ethyl acetate, ethyl lactate, ethyl butyrate, propyl acetate, propyl lactate, propyl butyrate, etc.); aldehydes (e.g., acetaldehyde, butyraldehyde, propionaldehyde, etc.).

[0033] According to a further embodiment, the sensor device is further configured to i) determine a further measured variable relating to the first silage sample while covering the first sample container, and / or ii) determine a further measured variable relating to the second silage sample while covering the second sample container. The analysis of the hydrogen / nitrogen-containing metabolite described in detail above can also be used in a comparable manner for other metabolites such as volatile organic compounds (volatile acids, alcohols, esters, aldehydes, etc.) or (hydrogen / nitrogen-free) such as carbon dioxide. This allows further advantages to be achieved with regard to the meaningfulness of the measurement results.

[0034] According to a further embodiment, the first sample container and / or the second sample container comprises at least one measuring device (e.g., one or more sensors) configured to determine at least one of the following parameters: oxygen, temperature, pH. This can have the advantage that a plurality of relevant parameters (multi-sensor technology) can be recorded and a corresponding amount of data is provided to obtain an overall picture of the silage system. For example, the Fig. 4 and Fig. 5, that surprisingly continuous, consistent, and complete time courses can be obtained with a large number of measurement series. In one example, a pH sensor or pH probe is arranged at least partially in a novel way in the silage sample, which can be present, for example, as porous wet material.

[0035] In addition to the gaseous substances mentioned above, parameters such as the aw value (MO-available water content) could be measured. Electrical conductivity can also be a relevant parameter.

[0036] According to a further embodiment, the measuring arrangement is configured such that, after a first measurement with respect to the first sample container, the measuring cover is moved to the second sample container for a second measurement with respect to the second sample container. This allows the concept to be implemented in an efficient and robust manner, whereby the same sensor (on the measuring cover) is used for a plurality of sample containers.

[0037] In the context of this document, the term “moving device” can refer to any structure suitable for moving the measuring lid between two sample containers. In one example (see also Fig. 1) The movement device is designed as a movable coupling structure (slide) that runs along a rail (on the support frame) and "carries" the measuring lid along. Instead of a rail, a conveyor belt, for example, can also be used. In another example, the movement device can be designed as a robot arm that transports the measuring lid between the sample containers or lifts and removes it. In another example, the measuring lid is stationary, while the sample containers are moved by the movement device.

[0038] According to a further embodiment, the measuring arrangement further comprises: a plurality of sample containers (e.g. three or more, four or more, five or more, eight or more, nine or more, ten or more), wherein the sample containers are arranged such that the measuring cover can be moved (continuously) between the sample containers by means of the movement device (and the pre-programmed series of measurements, ie fixed measuring positions in front of the sample containers, is independently and automatically traversed). This can have the advantage that a high level of measurement accuracy can be achieved while as little time and energy as possible is spent on moving the measuring cover.

[0039] In one example, the sample containers can be arranged in series (see e.g. Fig. 1). In another example, the sample containers can also be arranged in any other geometric shape, e.g., circular. Preferably, the sample containers can be arranged close to one another (e.g., as clusters) to reduce transport distances.

[0040] In one example, the sample containers are arranged vertically or horizontally in the main extension direction. Different sample containers can be arranged in the same or different orientations (e.g., upright or horizontal).

[0041] According to a further embodiment, the measuring cover is designed such that when the measuring cover is placed on the first sample container and / or the second sample container, an additional fluid space (in particular a gas space) is provided. This can have the advantage of providing an additional area for gas development (distribution) without additional effort. For example, the measuring cover can be partially designed as a container (with a gas volume), which is added to the sample volume of the sample container when the measuring cover is placed on the sample container.

[0042] According to a further embodiment, the first sample container and / or the second sample container is configured to store the first silage sample and / or the second silage sample (at least partially) aerobically. This can have the advantage of activating microbiological metabolic processes, the investigation of which enables a detailed understanding of the silage system. Furthermore, it can create a realistic measurement environment, since in one example, the oxidation behavior of the silage is of particular interest (illustratively: after opening the silo). In one example, oxygen can be supplied to the silage sample in the sample container. This can be continuous or time-limited. For example, the sample container can be open, or a controlled oxygen supply can be enabled by means of a cover structure (and a fluid channel located therein).

[0043] In one embodiment, the actual measurement (using the measuring lid) takes place when the measuring lid provides a gas-tight seal. Diffusion (i.e., the effort to equalize the concentration of gases between the gas pore space in the silage material and the gas space of the closed sample container or its supporting structure) results in the enrichment of ethanol concentrations in the (at least temporarily) limited volume of the closed sample container; this allows the ethanol emission rate to be determined. This changes, for example, due to the varying volatilization of ethanol (present in the liquid phase, after formation during the fermentation process) as silage temperatures (Tsi) increase. The emission rate and velocity can be used to draw conclusions about the chemical composition of the silage at the time of aerobic storage and, consequently, about the quality of the fermentation.

[0044] In one example, the short-term covering (e.g. < 3 minutes) leads to a closed gas space, whereby the oxygen in the sample container (including pore space in the silage) can still contain significant amounts of oxygen (see O2 concentration Fig. 4). Consequently, aerobic conditions still prevail in this example. The ethanol emission in this example still comes from the (variable) outgassing of ethanol, which was formed during the fermentation process and is already present in the material. However, the evaporation / volatilization changes, among other things, due to the changing silage temperatures.

[0045] In another example, the measuring lid can cover the first sample container and / or the second sample container for a longer set period of time until anaerobic conditions are established in the sample container. This leads to a change in the microbial metabolism, e.g., anaerobic yeast metabolism, of the present microbial community (stored or grown under partially aerobic conditions). The varying metabolic products under anaerobic conditions allow conclusions to be drawn about which microorganisms are present and at what level of activity. Some examples are as follows: i) renewed ethanol formation -> yeasts or enterobacteria predominate ii) renewed lactic and acetic acid formation -> lactic acid bacteria predominate iii) no metabolic change -> predominant obligate aerobic acetic acid bacteria are not active.

[0046] According to a further embodiment, the measuring arrangement further comprises an evaluation device configured to evaluate the determined measured variable, in particular to determine a quantity (concentration, volume) and / or velocity / rate of emission (emission current) of the organic metabolite. This can have the advantage that the measured values ​​can be evaluated directly and further conclusions can be drawn.

[0047] In one example, the evaluation device comprises one or more processors. In one example, the evaluation device is coupled to the sensor device (and / or one or more measuring devices). The coupling can be wired, wireless, or remote (e.g., via a network).

[0048] According to a further embodiment, the sensor device is configured to detect the metabolic product in the form of a fluid, in particular a gas. For this purpose, the gas can preferably be collected in a gas space (region of the sample volume, the support structure, or the measuring cover).

[0049] According to a further embodiment, the measuring cover is configured to seal the first sample container and / or the second sample container in a fluid-tight / gas-tight / hermetically manner.

[0050] According to a further embodiment, the first sample container and / or the second sample container has a cover structure, in particular wherein the respective measuring device is arranged on / in the cover structure. The cover structure can in particular have a fluid channel to enable a (regulated) fluid flow.

[0051] According to a further embodiment, the measuring arrangement has at least one holding structure (e.g. a tubular cylinder) which is configured to at least partially accommodate the first and / or the second sample container in a holding volume. In addition to storing the sample containers (in the support frame), the holding structure can represent an outer shell and offer mechanical protection for the sample containers. The holding structure preferably has insulation or thermal insulation in the holding volume. This thermal insulation prevents heat radiation from the (heated) silage samples (in the sample containers) inserted therein. This can, on the one hand, enable optimal detection of the temperature rise of the perishable silage samples and prevent possible cross-interference between the silage samples, i.e., prevent the heat radiation from one from leading to the heating of the other.

[0052] According to another embodiment, the first silage sample and / or the second silage sample have already undergone a storage process (ensiling process) at the start of the measurement. This enables testing under realistic practical conditions.

[0053] According to a further embodiment, the first silage sample and / or the second silage sample is (at least partially) fermented (or has undergone a fermentation process / silage process).

[0054] According to a further embodiment, the first silage sample and / or the second silage sample contains at least one silage additive or is free of silage additives. The effectiveness of these economical additives can be efficiently and reliably investigated using the described approach. Additive-free samples can be used for comparison.

[0055] According to a further embodiment, the first silage sample and / or the second silage sample contains microorganisms, in particular bacteria and / or fungi (in particular yeasts), and / or algae and / or single-cell organisms. These produce the metabolic products to be examined.

[0056] According to a further embodiment, the first sample container and / or the second sample container is a standard-compliant sample container, in particular with a sample volume in the range of 0.5 L to 10 L, more particularly 1 L to 2 L; in one example, 1.5-L glass jars are used, the most commonly used laboratory silo size, which can result in high comparability with other studies.

[0057] According to a further embodiment, the first silage sample and the second silage sample are identical or different with respect to common parameters within the management of silage (samples) along the entire process chain. This relates, but is not limited to, the following parameters: crop, type and line within a crop, harvesting method, harvesting time, chopping length, natural or influenced microbial community on / in the plant material, duration of air and oxygen exposure before silo closure, storage density of the silage, duration of aerobic conditions in the closed silo, air exposure at specific times or periods during fermentation, storage temperature and humidity during storage (anaerobic and / or aerobic), sunlight and UV light exposure during storage (anaerobic and / or aerobic), or composition of the sample material (individual silage sample or mixed sample of several feedstuffs or feed additives).

[0058] According to a further embodiment, the first silage sample and the second silage sample are identical or different. According to a further embodiment, the first measured variable and the second measured variable are identical or different.

[0059] According to another example, the measuring setup includes a control and / or regulation unit. This can, for example, automatically evaluate the measured parameters. For example, the measured gas concentrations of carbon dioxide, methane, and ethanol are automatically calculated with the duration of sealing and the volume of the enclosed gas space to calculate the gas emission rate. This provides direct information about the conversion processes in the material, as well as consequences for the environmental relevance and mass and energy losses of the sample material.

[0060] According to another example, the control and / or regulation unit can be used to adjust, change, or stop the measurement process in its components or the sequence of process steps during the process. This adjustment can be made when, for example, special events are triggered, such as reaching, exceeding, or falling below limits for individual measured variables. This allows, for example, (1) targeted measurement data acquisition during specific periods of aerobic deterioration of the silage with shorter measurement intervals, (2) skipping measurements on individual sample containers within a measurement cycle or terminating the measurement procedure as soon as all samples show a certain characteristic (e.g. silage temperature ≥ 2 K of room temperature) (skipping sample X as soon as it was 2 K warmer than the environment one or more times and is therefore to be classified as “reheated”) or (3) the post-treatment of individual measurement samples, e.g. with silage additives to contain, slow down and / or terminate the microbial conversion processes, which (positively) influences the emission behavior (this can provide important insights into how the treatment of reheated practical silos can be implemented in the best possible way and with the least possible effort).

[0061] According to a further embodiment, the method further comprises determining at least one of the following parameters: oxygen, temperature, pH, in the first sample container and in the second sample container, in particular by means of a measuring device internal to the sample container. This can be placed in the sample container, in particular in the silage sample.

[0062] According to one embodiment, the measuring setup is operated in an air-conditioned room to ensure constant room temperatures without diurnal fluctuations. This facilitates the determination of the temperature difference between the silage and the environment and thus the detection and measurement of silage heating during microbial respiration processes.

[0063] According to a further embodiment, the method further comprises, between covering one of the sample containers and determining one of the measured variables: waiting for gas to develop, in particular in a gas space, through the silage sample.

[0064] According to a further embodiment, the method further comprises: determining a (gas) emission rate (or the evaluation device is configured for this purpose). According to a further embodiment, the method further comprises: the automated calculation of the emission rates of the gases detected by the sensor devices using the measured gas concentrations, the volume of the affected gas space, and the duration of the closure of the gas space. In particular, the control and regulation of the measuring method and the sequence thereof can be carried out depending on certain actuators, such as the changes in the silage samples during the measuring cycle. Depending on certain, predetermined events, the measurement sequence can be automatically changed by the evaluation / control unit according to defined specifications.

[0065] It should be noted that embodiments of the invention have been described with reference to various subject matters. In particular, some embodiments have been described with reference to method claims, while other embodiments have been described with reference to apparatus claims. However, a person skilled in the art will appreciate from the foregoing and the following description that, unless otherwise stated, in addition to any combination of features belonging to one type of subject matter, any combination of features relating to different subject matters is also deemed to be disclosed by this document. This applies in particular also to features of the method claims and features of the apparatus claims.

[0066] The above-defined aspects and other aspects of the present invention will become apparent from the examples of embodiments to be described below and will be explained with reference to the examples of embodiments. The invention will be described in more detail below with reference to embodiments to which, however, the invention is not limited. Short description of the drawings Fig. 1 shows a measuring arrangement with a plurality of sample containers and a measuring lid, according to an exemplary embodiment of the invention. Fig. 2 schematically shows a silage sample, its components, and the sensors used for testing, according to an exemplary embodiment of the invention. Fig. 3 shows a measuring arrangement with a plurality of sample containers and a measuring cover, wherein a further gas space is provided during covering / measuring, according to an exemplary embodiment of the invention. The Fig. 4A to 4H show the time course of the measured variables ethanol and carbon dioxide emission rate of the silage samples as well as the oxygen concentration within the silage samples, according to an exemplary embodiment of the invention. The Fig. 5A to 5H show, for comparison, the temporal course of the measured variables ambient temperature as well as temperature and pH value within the silage samples, according to an exemplary embodiment of the invention. The Fig. 6A to 6C show the time course of the measured variable ammonia concentrations according to an exemplary embodiment of the invention. Detailed description of the drawings

[0067] The representations in the drawings are schematic. It should be noted that in different figures, similar or identical elements or features are provided with the same reference numerals or with reference numerals that differ from the corresponding reference numerals only within the first digit. To avoid unnecessary repetition, elements or features that have already been explained with reference to a previously described embodiment will not be explained again at a later point in the description.

[0068] Furthermore, spatially relative terms such as "front" and "back," "top" and "bottom," "left" and "right," etc., are used to describe the relationship of one element to another element, as illustrated in the figures. Thus, the spatially relative terms may apply to orientations used that differ from the orientation illustrated in the figures. Obviously, these spatially relative terms refer only to simplify the description and to the orientation shown in the figures and are not necessarily limiting, since a device according to an embodiment of the invention may assume orientations other than those illustrated in the figures, particularly when used.

[0069] Fig. 1 shows a measuring arrangement 100 with a plurality of sample containers 110, 120, 130, 140 and a measuring lid 150, according to an exemplary embodiment of the invention. The measuring arrangement 100 has a support frame 190 in which a plurality of sample containers 110, 120, 130, 140 are mounted horizontally (with the main extension direction). In this example, the sample containers are designed as cylindrical 1.5 L standard containers. A first sample container 110 contains a first silage sample 112, a second sample container 120 contains a second silage sample 122, etc. The silage samples are stored aerobically, thus enabling oxygen supply and corresponding microbiological processes.

[0070] The measuring arrangement 100 further comprises a measuring cover 150, which is coupled to a movement device 170. The movement device can comprise a carriage that can be moved along a rail of the support frame 190, thereby positioning the measuring cover 150 over each opening of one of the sample containers 110, 120, 130, 140. In the example shown, the measuring cover 150 is positioned at the first sample container 110 and covers or closes it. The measuring cover 150 has a sensor device 155 (see detailed view) which is configured to determine a measured variable indicative of an organic metabolite (here ethanol) with respect to the first silage sample 112 while the first sample container 110 is covered.

[0071] By means of the movement device 170, the measuring cover 150 can be moved (continuously) in the process direction P between positions 1 to 9, thus covering each of the sample containers individually and taking a corresponding measurement. The measured variable can be a gas emission, e.g., from the organic metabolite ethanol.

[0072] A specific example is described in detail below: Nine glass jars, each with a volume of 1.5 liters, are used as sample containers 110, 120, each containing a silage sample 112, 122 under practical conditions. Located in the center of the sample material, in each sample container 110, 120, are an oxygen sensor 118, a pH probe 117, and a temperature sensor 119. An ethanol sensor 155, common to all sample containers 110, 120, is provided in the measuring lid (movable lid) 150, which successively closes each gas chamber 180 in front of each sample container 110, 120. Furthermore, a CO2 sensor 156, common to all sample containers 110, 120, is provided in the measuring lid 150.

[0073] The temperature, O2 content, and pH value in the sample material 112, 122 are continuously measured. The lid 150 of the measuring bell is positioned in front of the first sample container 110 and seals it for, for example, 2 minutes. When the measuring bell is closed, the ethanol and CO2 sensors 155, 156 measure the concentration increase in the gas space 180; the rate of ethanol and CO2 outgassing (= emission flow) is calculated from the rate of enrichment. The lid 150 opens and moves to the second sample container 120, where it waits, for example, approximately 5 minutes. It closes it for, say, 2 minutes, opens, and moves to the third sample container 130. This is done for all nine sample containers, after which the next cycle begins with the first sample container 110. In this example, one cycle lasts one hour, ie the emission rates of ethanol and CO2 are determined hourly.

[0074] In this example, the test bench (the measurement setup 100) consists of an aluminum frame as a support frame 190, which forms the stable framework for mounting the sample containers (silos) 110, 120 and the measurement equipment. Within the frame 190, nine support structures 195 for the sample containers 110, 120 are mounted. Each of these structures consists of a tubular cylinder, which represents the outer shell and provides mechanical protection for the sample container jars, as well as an annular thermal insulation located therein (e.g., a ring jacket made of closed-pore Styrodur). This thermal insulation prevents heat radiation from the heated silage samples (in the sample containers 110, 120) placed therein. This allows, on the one hand, the optimal recording of the temperature rise of the perishing silage samples 112, 122 and prevents possible cross-interference of the silage samples, ie that the heat radiation of one does not lead to the heating of the other.The sample containers 110, 120, in this example cylindrical glasses with a nominal volume of 1.5 L, are inserted into the thermal insulation of the support structures 195 during the test setup.

[0075] The mechatronics of the mobile gas detector are positioned below the sample holders 195 and are controlled by a control device (microcontroller, evaluation / control unit 160). The gas detector 150 can be moved in front of the sample holders 195 so that all nine sample positions 1-9 can be addressed for the subsequent emission measurement. The mobile gas detector consists of two parts: a carriage for one-dimensional movement in front of the sample positions 1-9 (movement device 170) and the movable measuring cover 150. In this example, this is a plastic or metal plate containing the measuring sensors 155 and thus capable of sealing the tube cylinders (supporting structures 195) gas-tight. This (automatic) movable gas detector mimics a manual individual inspection. The carriage is moved using a guide rail, guide rollers, and a stepper motor-driven toothed belt.Counting the steps allows for precise movements and defined braking. Inductive switches, which are located on the slide and at defined positions on the sample holders, enable absolute, unambiguous, and precise positioning or position determination of the slide. The plastic / metal plate of the measuring cover 150 can be pressed onto the tubular cylinder 195 using a stepper motor with a threaded drive. Both motors have their own motor drivers, which are configured to provide the appropriate currents for movement and holding. Each individual motor step is triggered by the main control software. The stepper motor presses the measuring cover 150 onto the tubular cylinder 195 until an integrated spring is tensioned, which is attached to the plastic plate of the measuring cover 150 by means of a silent block. These two components ensure a gas-tight seal, even when compensating for unevenness or misalignments.A rubber seal further improves the sealing of the gas chamber 180. The status of whether the gas chamber 180 is closed or not is transmitted via a digital output to the evaluation / control unit 160, which then controls the measurement of the gas concentrations.

[0076] In addition to controlling the motors, the software's fundamental function is to precisely control the measuring process. This applies to the timing of the entire measuring cycle, as well as the duration of the individual measurements and, if necessary, the recovery time for the sensors. To avoid cumulative time errors, the internal clock is always queried for absolute values. Each individual position can be approached manually, and the measuring cover 150 can also be opened and closed manually. This enables individual measurements or tests, if required. For service purposes, a special menu can be called up to trigger further software actions, e.g., individual motor rotations or testing the position switches. Various parameters, especially time values, can be changed by the user and permanently stored in non-volatile memory.The calibration of the positions of the tube cylinders 195 as well as the position of the measuring cover 150 can be done automatically and is also permanently saved.

[0077] In this example, three sensors are installed within the measuring cover 150 (gas detector); additional sensors can be added modularly. A CO2 sensor (measuring range 0–approx. 50,000 ppm), an NH3 sensor (measuring range 30–300 ppm), and an ethanol sensor (measuring range 0–5,000 ppm) record the gas concentrations in the gas chamber 180 as soon as the measuring cover 150 closes the tube cylinder 195. In this way, in combination with the inductive switches, the concentration measurements can be assigned to the specific laboratory silages. In addition to these sensors, three additional stationary sensors are positioned within each silage sample. A temperature sensor (measuring range -20 - 200 °C), an O2 sensor (measuring range 0 - approx. 100%) and a pH value probe (measuring range 2 - 12 pH) measure the physical quantities within the porous silage material in the center of the silage sample 112, 122. The pH probe is placed approx.The probe is inserted 120 mm into the material. The temperature and O2 sensors are positioned within a perforated protective cover and also inserted 120 mm into the material. The sensor cables are routed to the respective data loggers in the gas chamber 180 via a rubber seal in the tubular cylinder 195. The total of 27 sensors in this example have a measurement interval of, for example, 300 s.

[0078] After the measurement begins, the mechatronic test bench control (evaluation / control unit 160) operates fully automatically in this example. The carriage of the mobile gas detector (movement device 170) moves to the zero position and then to sample position 1, i.e., in front of sample container 110. The measuring cover 150 is pressed against the outer shell of the sample holder 195, creating a closed gas chamber 180 in front of the silage sample 112, 122. The emitted gases, e.g., ethanol, ammonia, and CO2, accumulate in this chamber. The increase in concentration is measured by the sensors 155 as long as the gas chamber 180 remains closed. After, e.g., 120 s, the measuring cover 150 opens the gas chamber 180. The carriage moves to the next sample position, and after a recovery time of, e.g., 234 s, the next measurement begins. This recovery time allows the gas sensors 155 to fall to the zero level of atmospheric air.This control sequence is continued continuously until measurement position 9 has been measured. The carriage then moves to the zero position, a waiting time of, for example, 400 s is observed, and then the next measuring cycle for all samples begins. This additional waiting time ensures that each measuring cycle lasts exactly 1 hour, so that emission data are measured once an hour for each silage sample 112, 122. The measuring cycle can be interrupted at any time to allow the user to intervene, e.g. to work on the sensors. Thanks to the automated, high-precision, and reliable control of the measuring system (measuring cover 150 and movement device 170) described for this example to ensure the regular and correct closing of the gas spaces, one hourly measurement per silage sample was carried out error-free over a measuring period of, for example, 14 days.

[0079] In an exemplary embodiment, aspects of the invention may also be described as follows: i) Compared to conventional single-parameter data (e.g., silage temperature Tsi), the multiparameter data from the described approach are significantly more informative, as they are linked to five lines of evidence, for example, to provide insight into the complex process of silage oxidation. These data expand the understanding and are therefore very valuable for interpreting silage oxidation from different perspectives. For example, the sensitivity of microbial respiration to fluctuations in pH and ambient temperature can be directly monitored. ii) To test and evaluate different silage additives, the described approach can have a major advantage over conventional temperature measurements, as the conclusions can be based on a cross-interpretation of multi-parameter data. iii) For the precise measurement of CO2 and ethanol fluxes from multiple samples, each flow is measured by using a single sensor (mobile gas detector) instead of multiple gas sensors, completely eliminating the inherent errors between multiple sensors. v) Multi-parameter measurements to monitor the silage oxidation process can be carried out automatically.

[0080] Fig. Figure 2 schematically shows a silage sample 112, its components, and the sensors used for testing, according to an exemplary embodiment of the invention. In addition to the actual silage, the silage sample 112 contains a multitude of microorganisms, e.g., lactic acid bacteria, acetic acid bacteria, yeasts, and other (mold) fungi. In order to efficiently and reliably test / detect this complex system, the described method utilizes a multitude of sensors (multisensor technology), as schematically shown. Central to this is the detection of organic metabolites such as ethanol (ethanol sensor 155) and inorganic metabolites (CO2 sensor 156). Furthermore, the temperature (thermometer 119) and the pH value (pH probe 117) are determined as output parameters, while the oxygen content (O2 sensor 118) is examined as input parameter.The oxygen parameter is centrally located here, since the aerobic metabolism of the microorganisms and thus the O2 consumption, especially of the yeasts, has a large indirect and / or direct influence on the other parameters, such as the CO2 and heat production as well as the pH value drop during the degradation of lactic acid and its salts (lactate).

[0081] Fig. 3 shows a measuring arrangement 100 with a plurality of sample containers 110, 120, 130, 140 and a measuring lid 150, according to an exemplary embodiment of the invention. The example of Fig. 3 is that of Fig. 1, although the sample containers are shown in cross-section. It can be seen that the first sample container 110 and the second sample container 120 (the third and fourth sample containers 130, 140 are not shown in this example) are mounted in a support structure 195. This not only holds the sample container securely in position, but can also provide thermal insulation. Furthermore, the support structure 195 expands the gas space in front of the sample containers 110, 120, 130, 140. If this space is covered by the measuring cover 150, the emitted gases accumulate therein, and their concentration is measured by the gas sensors, e.g., 155 and 156.

[0082] Furthermore, this example shows that the first sample container 110 has a cover structure 116 that covers the silage sample 112. The cover structure 116 can be provided with a measuring device 115 and / or multiple sensors (e.g., 117, 118, 119) that determine parameters such as oxygen, temperature, or pH. Furthermore, the cover structure 116 can have one or more openings (in particular, fluid channels) through which gases can flow from the silage sample (into the gas space between the sample container 110, the holding structure 195, and the measuring lid 150). Furthermore, these openings allow air to penetrate to ensure aerobic conditions in the sample container. Additionally or alternatively, one or more sensors of the measuring device 115 can also be arranged directly in / on the silage sample 112.

[0083] In this example, the measuring cover 150 is designed such that when the first sample container 110 is placed on top (covered), an additional area, namely an extended gas space 180, is provided. Gas originating from the silage sample 112 can collect in this additional area to enable more reliable detection. In this example, the measuring cover 150 covers the upper side walls of the holding structure 195 from the outside. In another example, however, the upper side walls can also be covered from the inside. In other words, the measuring cover 150 is not placed over the side walls of the holding structure 195 (alternatively, directly over the sample container 110), but is inserted between them.

[0084] The Fig. Figures 4A to 4H show the temporal progression of the measured variables carbon dioxide and ethanol emission rates, as well as oxygen concentration, according to an exemplary embodiment of the invention. In principle, it can be said that during microbiological metabolic activity, the oxygen concentration decreases and the carbon dioxide emission rate increases.

[0085] The measurement data of O2, CO2 and ethanol were obtained from four replicates of maize silage samples without additive (CON-1 to CON-4, Fig. 4A to 4D) and from four replicates of maize silage samples with biological additives (BA-1 to BA-4, Fig. 4E to 4H). Three conclusions in particular can be drawn: i) Three lines of evidence were obtained for the silage oxidation process. ii) The described measurement setup is very well suited for multiple repetitions and with multiple parameters. iii) The effectiveness of the biological silage additive used is documented in the Fig. 4E-4H (in contrast to the Fig. 4A-4D) are clearly visible. The microbiological metabolism (and thus the reduction of oxygen and increase of carbon dioxide and ethanol) is significantly delayed. These continuous, consistent, and complete time courses are quite surprising, as hardly any studies on this topic are known from the state of the art.

[0086] The Fig. 5A to 5H show, for comparison, the temporal course of the measured variables ambient temperature, silage temperature (Tsi) and pH value of the silage samples, according to an exemplary embodiment of the invention.

[0087] In situ data of temperature (Tsi) and pH with four replicates were obtained from the same two groups of silage samples as in Fig. 4. The time courses of Tsi reflect the heating process of these samples, similar to standard measurements. The time courses of the pH value reflect the deacidification process of the samples and the metabolic process of the microorganisms in the silage, respectively. Overall, the two time courses provide Fig. 4 and Fig. 5 five lines of evidence for the oxidation process of silage.

[0088] In other words, the Fig. 4 and Fig. Figure 5 shows the measurements from a test in a 4×2 mode, in which one group (Group A) with four samples was free of additive inoculation, and the other group (Group B) was inoculated with a biological additive. First, the data from each group are fairly consistent, demonstrating the reproducibility of the described measurement setup. Second, five lines of evidence clearly demonstrated the effectiveness of the tested biological additive on the antioxidant properties of the tested silage samples. Other measurement modes, such as 3×3, 2×4, or any other combinations, are also possible.

[0089] The Fig. Figures 6A to 6C show the temporal progression of the measured variable ammonia concentrations according to an exemplary embodiment of the invention. The analog output signals of the ammonia sensors were recorded at the time of data acquisition. The measurement data were collected in a test run in which nine sample containers filled with grass silage were sampled. Three variants were used, each replicated three times (3x3 design): Fig. 6A: a control variant (sample containers 1, 4, 7), Fig. 6B: Test variant 1 treated with a biological silage additive consisting of homofermentative lactic acid bacteria (sample containers 2, 5, 8), and Fig. 6C: Test variant 2 treated with a biological silage additive consisting of heterofermentative lactic acid bacteria (sample containers 3, 6, 9).

[0090] The measured data show clear differences between the variants and a high degree of homogeneity within the replicates. In this example, treatment with homofermentative lactic acid bacteria led to a reduction in ammonia levels, while treatment with heterofermentative lactic acid bacteria led to an increase.

[0091] It should be noted that the term "comprising" does not exclude other elements or steps, and the use of the article "a" does not exclude a plurality. Elements described in connection with different embodiments may also be combined. It should also be noted that reference signs in the claims should not be construed to limit the scope of the claims. Reference symbol 100 measuring arrangement 110 First sample container 111 First sample volume 112 First silage sample 115 First measuring device 116 Cover structure 117 pH sensor 118 Oxygen sensor 119 Temperature sensor 120 Second sample container 121 Second sample volume 122 Second silage sample 125 Second measuring device 130 Third sample container 140 Fourth sample container 150 measuring caps 155 Sensor device, organic / ethanol sensor 156 Additional sensor device, inorganic / CO2 sensor 160 Evaluation device 170 Movement device 180 Fluid space / gas space 190 support frame 195 Support structure

Claims

[1] A measuring arrangement (100) for examining silage, the measuring arrangement (100) comprising: a first sample container (110) configured to receive a first silage sample (112); a second sample container (120) configured to receive a second silage sample (122); a measuring lid (150) which is arranged to cover the first sample container (110) or the second sample container (120), wherein the measuring cover (150) has a sensor device (155) which is arranged: to determine a measured variable relating to the first silage sample (112) while covering the first sample container (110), and / or to determine a measured variable relating to the second silage sample (122) while covering the second sample container (120), wherein the measured quantity relates to a hydrogen and / or nitrogen-containing metabolic product; and a movement device (170) which is coupled to the measuring cover (150) and which is configured to move the measuring cover (150) from the first sample container (110) to the second sample container (120), or vice versa. [2] The measuring arrangement (100) according to claim 1, wherein the hydrogen and / or nitrogen-containing metabolic product comprises at least one of: ethanol, ammonia, methane, nitrous oxide, at least one volatile organic component. [3] The measuring arrangement (100) according to claim 1 or 2, wherein the sensor device (155) is further configured: to determine a further measured variable with respect to the first silage sample (112) while covering the first sample container (110); and / or to determine a further measured variable with respect to the second silage sample (122) while covering the second sample container (120), wherein the further measured value relates to another metabolic product, in particular carbon dioxide, CO2. [4] The measuring arrangement (100) according to one of the preceding claims, wherein the first sample container (110) and / or the second sample container (120) comprises at least one measuring device (115, 125) which is configured to determine at least one of the following parameters: oxygen, temperature, pH, conductivity, available water content. [5] The measuring arrangement (100) according to one of the preceding claims, wherein the measuring arrangement (100) is arranged such that the measuring cover (150) is moved to the second sample container (120) after a first measurement with respect to the first sample container (110) for a second measurement with respect to the second sample container (120). [6] The measuring arrangement (100) according to claim 5, further comprising: a plurality of sample containers (110, 120, 130, 140), in particular five or more, wherein the sample containers (110, 120, 130, 140) are arranged such that the measuring cover (150) can be moved continuously between the sample containers (110, 120, 130, 140) by means of the movement device (170). [7] The measuring arrangement (100) according to one of the preceding claims, wherein the measuring cover (150) is designed such that when the measuring cover (150) is placed on the first sample container (110) and / or the second sample container (120), an additional fluid space (180), in particular gas space, is provided. [8] The measuring arrangement (100) according to one of the preceding claims, wherein the first sample container (110) and / or the second sample container (120) is configured to store the first silage sample (112) and / or the second silage sample (122) at least temporarily aerobically. [9] The measuring arrangement (100) according to one of the preceding claims, further comprising: an evaluation device (160) which is configured to evaluate the determined measured variable, in particular to determine a concentration of the metabolic product containing hydrogen and / or nitrogen. [10] The measuring arrangement (100) according to one of the preceding claims, further comprising at least one of the following features: wherein the sensor device (155) is configured to detect the metabolic product in the form of a fluid, in particular a gas; wherein the measuring cover (150) is configured to seal the first sample container (110) and / or the second sample container (120) in a gas-tight manner; wherein the first sample container (110) and / or the second sample container (120) has a cover structure (116), wherein the cover structure (116) has a fluid channel; wherein the measuring arrangement (100) has a holding structure (195) which is designed to at least partially accommodate the first sample container (110) or the second sample container (120) in a holding volume, in particular wherein the holding structure (195) has thermal insulation; wherein the first silage sample (112) and / or the second silage sample (122) has already undergone a storage process, in particular a silage process, at the start of the measurement; wherein the first silage sample (112) and / or the second silage sample (122) is at least partially fermented; wherein the first silage sample (112) and / or the second silage sample (122) comprises at least one silage additive or is free of silage additives; wherein the first silage sample (112) and / or the second silage sample (122) comprises microorganisms, in particular bacteria and / or fungi; wherein the metabolic product is microbiologically produced; wherein the first sample container (110) and / or the second sample container (120) is a standard-compliant sample container, in particular with a sample volume in the range 0.5 L to 10 L, further in particular 1 L to 2 L; wherein the first silage sample (112) and the second silage sample (122) are identical or different; where the first measured quantity and the second measured quantity are identical or different. [11] A method for testing silage, the method comprising: at least partially covering a first sample container (110) containing a first silage sample (112) by means of a measuring lid (150); Determining a measured variable with respect to the first silage sample (112) by means of a sensor device (155) arranged on the measuring cover (150); and thereafter at least partially covering the second sample container (120) containing a second silage sample (122) by means of the measuring lid (150); and Determining the measured variable with respect to the second silage sample (122) by means of the sensor device (155); wherein the measured variable relates to a hydrogen- and / or nitrogen-containing metabolic product. [12] The method according to claim 11, wherein determining the measured variable further comprises: determining a further measured variable, wherein the further measured value relates to another metabolic product, in particular carbon dioxide, CO2. [13] The method according to claim 11 or 12, further comprising: Determining at least one of the following parameters: oxygen, temperature, pH, in the first sample container (110) and in the second sample container (120), in particular by means of a measuring device (115, 125) internal to the sample container. [14] The method according to any one of claims 11 to 13, further comprising, between covering one of the sample containers (110, 120) and determining one of the measured variables: Waiting for gas evolution from the silage sample (112), in particular for accumulation in a gas space (180).

Images