Auflistung nach Autor:in "Sorg, Diana"

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Accuracy of methane emissions predicted from milk mid-infrared spectra and measured by laser methane detectors in Brown Swiss dairy cows
(2020) Denninger, Thomas Magnus; Schwarm, Angela; Dohme-Meier, Frigga; Sorg, Diana
Since heritability of CH4 emissions in ruminants was demonstrated, various attempts to generate large individual animal CH4 data sets have been initiated. Predicting individual CH4 emissions based on equations using milk mid-infrared (MIR) spectra is currently considered promising as a low-cost proxy. However, the CH4 emission predicted by MIR in individuals still has to be confirmed by measurements. In addition, it remains unclear how low CH4 emitting cows differ in intake, digestion, and efficiency from high CH4 emitters. In the current study, putatively low and putatively high CH4 emitting Brown Swiss cows were selected from the entire Swiss herdbook population (176,611 cows), using an MIR-based prediction equation. Eventually, 15 low and 15 high CH4 emitters from 29 different farms were chosen for a respiration chamber (RC) experiment in which all cows were fed the same forage-based diet. Several traits related to intake, digestion, and efficiency were quantified over 8 d, and CH4 emission was measured in 4 open circuit RC. Daily CH4 emissions were also estimated using data from 2 laser CH4 detectors (LMD). The MIR-predicted CH4 production (g/d) was quite constant in low and high emission categories, in individuals across sites (home farm, experimental station), and within equations (first available and refined versions). The variation of the MIR-predicted values was substantially lower using the refined equation. However, the predicted low and high emitting cows (n = 28) did not differ on average in daily CH4 emissions measured either with RC or estimated using LMD, and no correlation was found between CH4 predictions (MIR) and CH4 emissions measured in RC. When individuals were recategorized based on CH4 yield measured in RC, differences between categories of 10 low and 10 high CH4 emitters were about 20%. Low CH4 emitting cows had a higher feed intake, milk yield, and residual feed intake, but they differed only weakly in eating pattern and digesta mean retention times. Low CH4 emitters were characterized by lower acetate and higher propionate proportions of total ruminal volatile fatty acids. We concluded that the current MIR-based CH4 predictions are not accurate enough to be implemented in breeding programs for cows fed forage-based diets. In addition, low CH4 emitting cows have to be characterized in more detail using mechanistic studies to clarify in more detail the properties that explain the functional differences found in comparison with other cows. © 2019 American Dairy Science Association®
Comparison of a laser methane detector with the GreenFeed and two breath analysers for on-farm measurements of methane emissions from dairy cows
(2018) Sorg, Diana; Difford, G.F.; Mühlbach, S.
To measure methane (CH4) emissions from cattle on-farm, a number of methods have been developed. Combining measurements made with different methods in one data set could lead to an increased power of further analyses. Before combining the measurements, their agreement must be evaluated. We analysed data obtained with a handheld laser methane detector (LMD) and the GreenFeed system (GF), as well as data obtained with LMD and Fourier Transformed Infrared (FTIR) and Non-dispersive Infrared (NDIR) breath analysers (sniffers) installed in the feed bin of automatic milking systems. These devices record short-term breath CH4 concentrations from cows and make it possible to estimate daily CH4 production in g/d which is used for national CH4 emission inventories and genetic studies. The CH4 is released by cows during eructation and breathing events, resulting in peaks of CH4 concentrations during a measurement which represent the respiratory cycle. For LMD, the average CH4 concentration of all peaks during the measurement (P_MEAN in ppm * meter) was compared with the average daily CH4 production (g/d) measured by GF on 11 cows. The comparison showed a low concordance correlation coefficient (CCC; 0.02) and coefficient of individual agreement (CIA; 0.06) between the methods. The repeated measures correlation (rp) of LMD and GF, which can be seen as a proxy for the genetic correlation, was, however, relatively strong (0.66). Next, based on GF, a prediction equation for estimating CH4 in g/d (LMD_cal) using LMD measurements was developed. LMD_cal showed an improved agreement with GF (CCC = 0.22, CIA = 0.99, rp = 0.74). This prediction equation was used to compare repeated LMD measurements (LMD_val in g/d) with CH4 (g/d) measured with FTIR (n = 34 cows; Data Set A) or NDIR (n = 39 cows; Data Set B) sniffer. A low CCC (A: 0.28; B: 0.17), high CIA (A: 0.91; B: 0.87) and strong rp (A: 0.57; B: 0.60) indicated that there was some agreement and a minimal re-ranking of the cows between sniffer and LMD. Possible sources of disagreement were cow activity (LMD: standing idle; sniffer: eating and being milked) and the larger influence of wind speed on LMD measurement. The LMD measurement was less repeatable (0.14â€Ì0.27) than the other techniques studied (0.47â€Ì0.77). Nevertheless, GF, LMD and the sniffers ranked the cows similarly. The LMD, due to its portability and flexibility, could be used to study CH4 emissions on herd or group level, as a validation tool, or to strengthen estimates of genetic relationships between small-scale research populations. © 2018 Elsevier B.V.
Comparison of methods to measure methane for use in genetic evaluation of dairy cattle
(2019) Garnsworthy, Philip C.; Difford, Gareth F.; Bell, Matthew J.; Sorg, Diana
Partners in Expert Working Group WG2 of the COST Action METHAGENE have used several methods for measuring methane output by individual dairy cattle under various environmental conditions. Methods included respiration chambers, the sulphur hexafluoride (SF6) tracer technique, breath sampling during milking or feeding, the GreenFeed system, and the laser methane detector. The aim of the current study was to review and compare the suitability of methods for large-scale measurements of methane output by individual animals, which may be combined with other databases for genetic evaluations. Accuracy, precision and correlation between methods were assessed. Accuracy and precision are important, but data from different sources can be weighted or adjusted when combined if they are suitably correlated with the "true" value. All methods showed high correlations with respiration chambers. Comparisons among alternative methods generally had lower correlations than comparisons with respiration chambers, despite higher numbers of animals and in most cases simultaneous repeated measures per cow per method. Lower correlations could be due to increased variability and imprecision of alternative methods, or maybe different aspects of methane emission are captured using different methods. Results confirm that there is sufficient correlation between methods for measurements from all methods to be combined for international genetic studies and provide a much-needed framework for comparing genetic correlations between methods should these become available. Quelle: Verlagsinformation
Measuring livestock CH4 emissions with the laser methane detector: a review
(2022) Sorg, Diana
The handheld, portable laser methane detector (LMD) was developed to detect gas leaks in industry from a safe distance. Since 2009, it has also been used to measure the methane (CH4) concentration in the breath of cattle, sheep, and goats to quantify their CH4 emissions. As there is no consensus on a uniform measurement and data-analysis protocol with the LMD, this article discusses important aspects of the measurement, the data analysis, and the applications of the LMD based on the literature. These aspects, such as the distance to the animal or the activity of the animals, should be fixed for all measurements of an experiment, and if this is not possible, they should at least be documented and considered as fixed effects in the statistical analysis. Important steps in data processing are thorough quality control and reduction in records to a single point measurement or "phenotype" for later analysis. The LMD can be used to rank animals according to their CH4 breath concentration and to compare average CH4 production at the group level. This makes it suitable for genetic and nutritional studies and for characterising different breeds and husbandry systems. The limitations are the lower accuracy compared to other methods, as only CH4 concentration and not flux can be measured, and the high amount of work required for the measurement. However, due to its flexibility and non-invasiveness, the LMD can be an alternative in environments where other methods are not suitable or a complement to other methods. It would improve the applicability of the LMD method if there were a common protocol for measurement and data analysis developed jointly by a group of researchers. © 2021 by the author
Perspektiven für eine umweltverträgliche Nutztierhaltung in Deutschland
(Umweltbundesamt, 2021) Sorg, Diana; Klatt, Anne; Plambeck, Nils Ole; Köder, Lea; Deutschland. Umweltbundesamt; Balzer, Frederike; Biewald, Anne; Bilharz, Michael; Ehlers, Knut; Frische, Tobias; Fuchs, Doris; Geupel, Markus; Hofmeier, Maximilian; Jarikova, Julia; Lehmann, Simone; Marx, Marc; Stark, Christiane; Vogel, Ines; Wechsung, Gabriele
Unsere Nutztierhaltung schädigt die Umwelt und belastet das Klima. Die negativen Umwelt- und Klimawirkungen lassen sich durch kurzfristig umsetzbare verfahrenstechnische Maßnahmen, eine bessere räumliche Verteilung der Tiere und eine Verringerung von Produktion und Konsum tierischer Lebensmittel deutlich mindern. Zu diesem Schluss kommt ein aktuelles Hintergrundpapier des âĄ UBAâĄ zu "Perspektiven für eine umweltverträgliche Nutztierhaltung". Quelle: http://www.umweltbundesamt.de
Sind alte Haustierrassen "robuster"?
(2018) Frölich, Kai; Ballweg, Ines Carolina; Sorg, Diana
Über Inhaltsstoffe der Milch von Thüringer Waldziegen und Weißen Deutschen Edelziegen
(2020) Sorg, Diana; Jandowsky, Anabell; Frölich, Kai
Ziegenmilchprodukte finden weltweit steigendes Interesse. Die Milch von verschiedenen Ziegenrassen in Deutschland ist bisher wenig charakterisiert und standardisiert. Daher wurden von neun Thüringer Wald Ziegen (TWZ), als Vertreterinnen einer gefährdeten, lokalen, alten, deutschen Ziegenrasse, und von zehn Weißen Deutschen Edelziegen (WDE), als Referenz einer häufig genutzten Hochleistungsrasse Milchproben, an Tag 0, 4, 20 und 59 der Laktation auf verschiedene ernährungsphysiologische Parameter untersucht. Durch die gemeinsame Haltung und Fütterung auf einem Betrieb (Tierpark Arche -Warder) wurden viele externe Einflussfaktoren auf die Inhaltsstoffe wie unterschiedliche Fütterung, Management, Saison ausgeschlossen. Rasseunterschiede zeigten sich bei der Zellzahl (TWZ: 3,8-50,6 x105/ml, WDE: 1,7-6,0 x105/ml, an Tag 4 p<0,05), ohne dass jedoch eine Mastitis festgestellt werden konnte. Weiterhin unterschieden sich die Rassen entweder im Trend (p<0,1): bei gesättigten Fettsäuren (SFA; TWZ: 68,22-70,00 %; WDE: 63,23-65,23 %, an Tag 59 p<0,1), einfach ungesättigten Fettsäuren (MUFA; TWZ: 25,40-27,31 %; WDE: 28,93-32,23 %; an Tag 59 p<0,1), Omega-3-FS (n3; TWZ: 0,91-1,43 %; WDE: 0,92-1,30 %; an Tag 0 p<0,1), Thrombogenitäts-Index (TI; TWZ: 1,49-1,68; WDE: 1,22-1,57; an Tag 20 und 59 p<0,1) oder signifikant (p<0,05): bei kurzkettigen Fettsäuren (SCFA; TWZ: 6,61-8,51 %; WDE: 5,29-8,19 %; an Tag 4 p<0,05), einer konjugierten Linolsäure (CLA, C18:2 cis-9,trans-11; TWZ: 0,53-1,18 %; WDE: 0,42-0,89 %; an Tag 0 und 20 p<0,05, an Tag 4 p<0,1), beim Verhältnis von Omega-6- zu Omega-3-FS (n6/n3; TWZ: 2,43-2,58; WDE: 2,57-2,87; an Tag 0, 4 und 59 p<0,05). Der Cholesteringehalt war an Tag 0 und 4 bei der TWZ nicht signifikant, jedoch quantitativ deutlich niedriger (378,82 (my)g/ml; 150,36 (my)g/ml) als bei der WDE (505,75 (my)g/ml; 223,38 (my)g/ml). Insgesamt konnte jedoch nicht festgestellt werden, dass eine der beiden Rassen durchgehend ernährungsphysiologisch günstigere Inhaltsstoffkonzentrationen aufwies. Die Milch der TWZ wurde in dieser Studie zum ersten Mal umfassend auf verschiedene Inhaltsstoffe untersucht und mit der von WDE verglichen. © M. & H. Schaper GmbH & Co.
Unterschätztes Treibhausgas Methan
(Umweltbundesamt, 2022) Appelhans, Johanna; Böttcher, Christian; Kessler, Kai; Mielke, Christian; Nowack, Anja; Purr, Katja; Schwetje, Anja; Sorg, Diana; Tambke, Jens
Methan ist nach Kohlendioxid das zweitwichtigste Treibhausgas. Daneben ist Methan ein wichtiger Vorläuferstoff für die Bildung von bodennahem Ozon. Ozon ist mit negativen Gesundheitseffekten verbunden und schädigt Ökosysteme und Nutzpflanzen. Eine Minderung der Methanemissionen trägt also sowohl zum Klimaschutz als auch zum Schutz der menschlichen Gesundheit und zum Schutz von Ökosystemen bei. Es ist daher wichtig, in den kommenden Jahren weltweit eine Minderung der Methanemissionen anzustoßen und weiter voranzubringen. Seit einigen Jahren gibt es sowohl auf internationaler als auch auf europäischer Ebene Bestrebungen, die Methanemissionen deutlich zu senken und konkrete Minderungsziele festzulegen. Trotz der angestoßenen Initiativen zur Methanminderung ist jedoch vielen Menschen noch nicht bewusst, wie notwendig eine Reduzierung der CH4-Emissionen ist und welchen Nutzen sie bringen kann. Das Positionspapier des Umweltbundesamtes informiert über die Wirkungen und die wichtigsten Emissionsquellen von Methan und zeigt konkrete Handlungsempfehlungen und Maßnahmen zur Methanreduktion auf nationaler Ebene und weltweit auf. Das UBA-Papier richtet sich vor allem an politische Entscheidungsträger*innen. Quelle: www.umweltbundesamt.de
Wie viel Milch und Fleisch kann in Deutschland umweltverträglich erzeugt werden?
(2023) Dreisbach, Nele; Biewald, Anne; Dühr, Nick; Sorg, Diana
Wie viele Tiere können wir umweltverträglich halten?
(2023) Dreisbach, Nele; Biewald, Anne; Dühr, Nick; Sorg, Diana; Balzer, Frederike