Thermodynamic assessment of heat stress in dairy cattle: lessons from human biometeorology

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, precision farming of high-yielding animals in a drastically changing climate calls for more effective prediction and alleviation of heat stress. The present paper revisits classical work on human biometeorology, particularly the apparent temperature scale, to draw inspiration for advancing research on heat stress in dairy cattle. The importance of a detailed, mechanistic understanding of heat transfer and thermoregulation is demonstrated and reiterated. A model from the literature is used to construct a framework for identifying and characterizing conditions of potential heat stress. New parameters are proposed to translate the heat flux calculations based on heat-balance models into more tangible and more useful meteorological indices, including an apparent temperature for cattle and a thermoregulatory exhaustion index. A validation gap in the literature is identified as the main hindrance to the further development and deployment of heat-balance models. Recommendations are presented for systematically addressing this gap in particular and continuing research within the proposed framework in general

Applied Research Note: Survival of Escherichia coli and temperature development during composting of chicken manure with a typically low carbon/nitrogen ratio and moisture content

The presence of pathogens, e.g., Escherichia coli (E. coli), in chicken manure can potentially lead to serious infections and foodborne diseases when spread on land as organic fertilizer. Therefore, it is essential to inactivate these bacteria before land application. The aim of the present study was to determine the survival of E. coli and the temperature development in compost piles during composting of chicken manure with a typically low carbon/nitrogen (C/N) ratio and moisture content (MC). In a summer and winter trial, chicken manure piles were stacked in 1) uncovered static piles, 2) covered static piles, and 3) periodically turned piles. Samples were inoculated with a nonpathogenic E. coli strain at levels of 107 cfu/g and placed at subsurface and center locations of the piles. Within 24 h, E. coli were undetectable by direct count in all piles and at all sample locations. By d 28, all samples were also negative for E. coli by enrichment. Despite the suboptimal composting conditions with an initial C/N ratio of 10:1 and an MC below 40%, temperatures within all piles mainly exceeded 50°C within the first 24 h. Statistical analyses showed that the sample location and the total hours at temperatures ≥50 and 55°C in the piles had significant influences on the survival of E. coli in the chicken manure compost. The season and manure treatment method had no significant effects on the presence of E. coli

Influence of barn climate, body postures and milk yield on the respiration rate of dairy cows

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 to three randomly chosen measurement days per week between 0700 h and 1500 h (GMT + 0100 h) by counting right thoracoabdominal movements of the cows. Simultaneously with RR measurements, cow body postures (standing vs. lying) were documented. Cows’ milk yield and days in milk were recorded daily. The ambient temperature and relative humidity of the barn were recorded every 5 min to calculate the current temperature-humidity index (THI). The data were analyzed for interactions between THI and cow-related factors (body postures and daily milk yield) on RR using a repeated measurement linear mixed model. There was a significant effect of the interaction between current THI category and body postures on RR. The RRs of cows in lying posture in the THI < 68, 68 ≤ THI < 72 and 72 ≤ THI < 80 categories (37, 46 and 53 breaths per minute (bpm), respectively) were greater than those of standing cows in the same THI categories (30, 38 and 45 bpm, respectively). For each additional kilogram of milk produced daily, an increase of 0.23±0.19 bpm in RR was observed. Including cow-related factors may help to prevent uncertainties of RR in heat stress predictions. In practical application, these factors should be included when predicting RR to evaluate heat stress on dairy farm

Methane Emission Characteristics of Naturally Ventilated Cattle Buildings

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 methane emission data collected during contrasting seasons from two naturally ventilated dairy cattle buildings with concrete floor and performed a second order polynomial regression. We found a parabolic temperature dependence of the methane emissions irrespective of the measurement site and setup. The position of the parabola vertex varied when considering different hours of the day. The circadian rhythm of methane emissions was represented by the pattern of the fitted values of the constant term of the polynomial and could be well explained by feeding management and air flow conditions. We found barn specific emission minima at ambient temperatures around 10 °C to 15 °C. As this identified temperature optimum coincides with the welfare temperature of dairy cows, we concluded that temperature regulation of dairy cow buildings with concrete floor should be considered and further investigated as an emission mitigation measure. Our results further indicated that empirical modeling of methane emissions from the considered type of buildings with a second order polynomial for the independent variable air temperature can increase the accuracy of predicted long-term emission values for regions with pronounced seasonal temperature fluctuation

Uncertainty in the measurement of indoor temperature and humidity in naturally ventilated dairy buildings as influenced by measurement technique and data variability

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 and position of the sensors) and the analysis methodology adds to the uncertainty of the applied measurement technique. To assess the suitability of different sensor positions, in situations where monitoring in the direct vicinity of the animals is not possible, we collected long-term data in two naturally ventilated dairy barns in Germany between March 2015 and April 2016 (horizontal and vertical profiles with 10 to 5 min temporal resolution). Uncertainties related to the measurement setup were assessed by comparing the device outputs under lab conditions after the on-farm experiments. We found out that the uncertainty in measurements of relative humidity is of particular importance when assessing heat stress risk and resulting economic losses in terms of temperature-humidity index. Measurements at a height of approximately 3 m–3.5 m turned out to be a good approximation for the microclimatic conditions in the animal occupied zone (including the air volume close to the emission active zone). However, further investigation along this cross-section is required to reduce uncertainties related to the inhomogeneous distribution of humidity. In addition, a regular sound cleaning (and if possible recalibration after few months) of the measurement devices is crucial to reduce the instrumentation uncertainty in long-term monitoring of relative humidity in dairy barns. © 2017 The Author

Opening Size Effects on Airflow Pattern and Airflow Rate of a Naturally Ventilated Dairy Building-A CFD Study

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 rate inside the NVD building as an alternative to full scale and scale model experiments. ANSYS 2019R2 was used for creating model geometry, meshing, and simulation. Eight ventilation opening combinations and 10 different reference air velocities were used for the series of simulation. The data measured in a large boundary layer wind tunnel using a 1:100 scale model of the NVD building was used for CFD model validation. The results show that CFD using standardk-epsilon turbulence model was capable of simulating airflow in and outside of the NVD building. Airflow patterns were different for different opening scenarios at the same external wind speed, which may affect cow comfort and gaseous emissions. Guiding inlet air by controlling openings may ensure animal comfort and minimize emissions. Non-isothermal and transient simulations of NVD buildings should be carried out for better understanding of airflow patterns

Opening Size E ects on Airflow Pattern and Airflow Rate of a Naturally Ventilated Dairy Building : A CFD Study

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 rate inside the NVD building as an alternative to full scale and scale model experiments. ANSYS 2019R2 was used for creating model geometry, meshing, and simulation. Eight ventilation opening combinations and 10 different reference air velocities were used for the series of simulation. The data measured in a large boundary layer wind tunnel using a 1:100 scale model of the NVD building was used for CFD model validation. The results show that CFD using standard k-ε turbulence model was capable of simulating airflow in and outside of the NVD building. Airflow patterns were different for different opening scenarios at the same external wind speed, which may affect cow comfort and gaseous emissions. Guiding inlet air by controlling openings may ensure animal comfort and minimize emissions. Non-isothermal and transient simulations of NVD buildings should be carried out for better understanding of airflow patterns

Non-linear temperature dependency of ammonia and methane emissions from a naturally ventilated dairy barn

Ammonia (NH3) and methane (CH4) emissions from naturally ventilated dairy barns affect the environment and the wellbeing of humans and animals. Our study improves the understanding of the dependency of emission rates on climatic conditions with a particular focus on temperature. Previous investigations of the relation between gas emission and temperature mainly rely on linear regression or correlation analysis. We take up a preceding study presenting a multilinear regressionmodel based onNH3 and CH4 concentration and temperaturemeasurements between 2010 and 2012 in a dairy barn for 360 cows inNorthern Germany.We study scatter plots and non-linear regressionmodels for a subset of these data and show that the linear approximation comes to its limits when large temperature ranges are considered. The functional dependency of the emission rates on temperature differs among the gases. For NH3, the exponential dependency assumed in previous studies was proven. For methane, a parabolic relation was found. The emissions show large daily and annual variations and environmental impact factors like wind and humidity superimpose the temperature dependency but the functional shape in general persists. Complementary to the former insight that high temperature increases emissions, we found that in the case of CH4, also temperatures below 10 C lead to an increase in emissions from ruminal fermentation which is likely to be due to a change in animal activity. The improved prediction of emissions by the novel non-linear model may support more accurate economic and ecological assessments of smart barn concepts

A-IQI : Austrian Inpatient Quality Indicators

Zugleich gedruckt erschienen im Universitätsverlag der TU Berlin unter der ISBN 978-3-7983-2249-3.Qualitätsmanagement baut auf den Säulen Struktur-, Prozess- und Ergebnisqualität auf. In Niederösterreich wie auch in Gesamtösterreich wurde das Augenmerk im Krankenhausbereich bisher vorrangig auf Strukturen und Prozesse gelegt. Mittlerweile sind Strukturvorgaben flächendeckend erfüllt und die Abläufe liegen im Verantwortungsbereich der leitenden Personen in den Abteilungen. Doch wie sich die Patientenversorgung bei bestimmten Behandlungen oder Erkrankungen darstellt, wissen die wenigsten Leistungserbringer. Der nächste Schritt in Österreich muss nun die Ergebnismessung sein. Seit 2008 beschäftigt sich die Niederösterreichische Landeskliniken-Holding mit dem Thema medizinische Qualität messbar zu machen. Ziel war und ist anhand von bereits vorhandenen Routinedaten darzustellen, wo ein Leistungserbringer steht. Nur wenn Qualität gemessen wird, kann man sich vergleichen, einordnen und wenn nötig Verbesserungsmaßnahmen ergreifen. Die Qualitätsmessung ist in Österreich noch sehr neu. Es gibt bereits einige Qualitätsregister die detailliertere Informationen liefern als die Routinedaten. Die Eingabe ist jedoch zeitaufwändig und die Datenqualität hängt sehr stark von der Compliance der Leistungserbringer ab. Das vorliegende Dokument ist durch die Zusammenarbeit der Niederösterreichischen Landeskliniken-Holding mit dem deutschen Klinikenträger HELIOS, dem Schweizer Bundesamt für Gesundheit und dem Fachgebiet Strukturentwicklung und Qualitätsmanagement im Gesundheitswesen an der Technischen Universität Berlin entstanden. Es beinhaltet die in Deutschland entwickelten und auch in der Schweiz eingesetzten Indikatoren aus dem HELIOS-System (G-IQI, German Inpatient Quality Indicators, Mansky et al. 2010), die an die Kodierverfahren des österreichischen Dokumentations- und Abrechnungssystems angepasst wurden. Was wird gemessen? ■ Mortalität ■ Mengen für bestimmte Behandlungen, Operationen ■ Wahl der Operationstechnik, des Behandlungsverfahrens ■ Intensivhäufigkeit bei bestimmten Operationen ■ Elemente des Behandlungsprozesses ■ Wiederaufnahmen ■ Komplikationen, Re-Eingriffe Die Grundlagen dieses Indikatorensystems, wie Berechnungslogik oder Risikoadjustierung, sowie die genauen Indikatorendefinitionen der Austrian Inpatient Quality Indicators mit Diagnosen, medizinischen Einzelleistungen und demographischen Daten werden in diesem Band erläutert und sind somit frei zugänglich. Die Qualitätsmessung schafft Bewusstsein bei allen Beteiligten und zeigt Abweichungen strukturiert auf, der Grund für diese bleibt jedoch unklar. Um einen kontinuierlichen Verbesserungsprozess zu erreichen, stellt das Peer Review Verfahren einen zentralen Punkt und das Herzstück dieses Qualitätsmanagementsystems dar. Erst wenn bei Auffälligkeiten auf Ebene der Krankengeschichten strukturiert von Experten analysiert wird, kann beurteilt werden, ob Verbesserungspotential besteht, die Datenqualität schlecht ist oder das Ergebnis „berechtigterweise“ nicht im Zielbereich liegt. Einem österreichweiten Benchmarking steht nun nichts mehr im Wege

Heat Load-Induced Changes in Lying Behavior and Lying Cubicle Occupancy of Lactating Dairy Cows in a Naturally Ventilated Barn

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 cows throughout the day during three summer months and three winter months. The study was conducted in summer 2016 and in winter 2016/17 in a naturally ventilated barn in Brandenburg, Germany. The determined temperaturehumidity index (THI) of the barn was calculated using the measured ambient temperature and relative humidity at eight locations inside the barn. The THI was used to define the heat load the cows were exposed to. The activity of the cows was measured with accelerometers, and a video recording was made to analyze the occupancy of the three rows of lying cubicles. The results indicated that increasing heat load led to a decrease in lying time; therefore, the daily lying time differed between summer and winter months. In addition, there were different patterns of lying behavior during the course of the day, depending on the season. A sharp decline in lying time could be observed especially in the afternoon hours during the summer. The occupancy of lying cubicles was also influenced by the heat load. The data could be helpful to enable evaluation with algorithms for early detection of heat load