Research

Pferdeklinik Mühlen

Institut für Veterinär-Pathologie, Universität Leipzig

We showed that sheep preferred ragwort without any harmful effects. The more ragwort was available and the more it contained

sugar, the higher the amount ingested by the sheep. Ragwort accounted for a significantly lower yield proportion of ingested biomass in the second year even though its number of flowers doubled. The yield of biomass of other herbs increased. From the point of view of animal health and nature conservation, sheep grazing on ragwort might be an option to reduce the amount of ragwort in pastures.

Universität Hamburg

Abteilung Angewandte Pflanzenökologie

Ohnhorststr. 18

22609 Hamburg

Dr. Aiko Huckauf

Stiftung Naturschutz Schleswig-Holstein

Eschenbrook 4

24113 Molfsee

PD Dr. Frank Pessler, Helmholtz-Zentrum für Infektionsforschung, Hannover

Poster Abstracts:

1. Bogun K, Peh E, Siekmann L, Plötz M, Kittler S; Untersuchungen zur Anwendung ausgewählter Säuren und Pflanzenextrakte sowie deren Kombination als Reduktionsmethode von Campylobacter spp. auf Hähnchenfleisch. 62. Arbeitstagung des Arbeitsgebietes Lebensmittelsicherheit und Verbraucherschutz der DVG, 25. bis 28. Oktober 2022

2. Bogun K, Peh E, Plötz M, Kittler S; Combination of a phage cocktail and an organic acid cocktail to reduce Campylobacter in broiler chickens - Examination of possible synergistic effects. 2nd German Phage Symposium, 23.-24.5.2022 Universität Hohenheim

3. Bogun K, Peh E, Siekmann L, Plötz M, Kittler S; Examination of selected organic acids and plant extracts and their combination as a reduction method against Campylobacter on chicken meat Zoonoses 2022 - International Symposium on Zoonoses Research 05.-07.10.2022 Berlin

In this work we used samples with artificially induced damage for establishing protocols for flow cytometric analysis of sperm viability, as well as computer assisted analysis of sperm motility patterns. Moreover, we found that samples previously enriched with damaged sperm were especially useful for testing the effectiveness of different sperm selection procedures.

The major aim of this work was to evaluate how microfluidic chips perform in selecting high quality sperm, i.e., in comparison to other techniques such as swim-up and percoll density gradient centrifugation. In addition, we planned to test if sperm selected, using microfluidic chips exhibit better motility behavior, increased fertilization capacity in vitro, and wanted to evaluate the performance with the flow cytometric X/Y-sperm sorting.

Both, freshly diluted and cryopreserved sperm were tested also taking into account the variation among individuals. We determined that when using microfluidic sorting and swim-up methods, sperm recovery was low, however, sperm were of superior quality. Sperm recovery was higher after using percoll density gradient centrifugation, but this coincided with the presence of increased numbers of membrane damaged and motile sperm. In addition, the presence of a relatively high ratio of motile sperm in high quality sperm samples exhibited characteristic kinematic parameters including increased movement velocity and linearity; which was maintained when specimens were investigated in viscous media, mimicking oviductal fluid. In our hands, when compared with ordinary processing, remained that the increased sperm quality after microfluidic selection did not result an increased in vitro embryo production. Nonetheless, performing microfluidic sperm selection prior to flow cytometric sorting of X/Y-sperm appeared beneficial; since this improved initial sperm quality to required levels, reduced contents of debris and dead sperm during FACS sorting, and enabled to significantly improve sorting speed and the correctly oriented X-chromosome bearing sperm numbers in the population.

In conclusion, the use of microfluidic chips has great potential in reproductive medicine and veterinary assisted reproduction technologies. This is not only beneficial for any easier selection and enrichment of high quality sperm samples, which are more likely to fertilize an oocyte, but as a processing step, also for fulfilling the requirements needed for successful flow cytometric sorting of X/Y chromosome bearing sperm.

The use of microfluidic chips has great potential in reproductive medicine and veterinary assisted reproduction technologies. This is not only beneficial for any easier selection and enrichment of high quality sperm samples, which are more likely to fertilize an oocyte, but as a processing step, also for fulfilling the requirements needed for successful flow cytometric sorting of X/Y chromosome bearing sperm.

https://elib.tiho-hannover.de/receive/tiho_mods_00012249

Calisici, Oguz, Phytobiotics GmbH

Alkabes, Stephane, Masterrind GmbH Verden

Jakob Aundrup, Schweinegesundheitsdienst der Landwirtschaftskammer Niedersachsen