Effects of different light intensities on quality of spermatozoa in rabbits

[EN] The present study evaluated the effects of light intensity on semen production in rabbits. Bucks were allocated to two groups which were exposed to a lighting program (16L:8D) with different light intensities (Group 1: 200 Lux). Prior to the thirteen weeks duration of the examination period, bucks were adapted to the light system for two months and conditioned for semen collection for one month. There was no effect of light intensity on libido, concentration and motility of spermatozoa. However, there were more bucks in group 1 delivering ejaculate with the gel fractions (P = 0.0065) and more foreign particles were observed in the ejaculates (P = 0.0007) compared to male rabbits from group 2. The first week of semen collection also revealed a light intensity effect on spermatozoa obtained by swim-up procedure. The concentrations of spermatozoa from group 2 were higher than those from group 1 (P < 0.0001). This effect was only slightly visible for motility after swim-up (P = 0.067).Besenfelder, U.; Theau-Clément, M.; Sabbioni, E.; Castellini, C.; Renieri, T.; Havlicek, V.; Huber, T.... (2005). Effects of different light intensities on quality of spermatozoa in rabbits. World Rabbit Science. 12(4):227-234. doi:10.4995/wrs.2004.570SWORD22723412

Staphylococcus aureus genotype B and other genotypes isolated from cow milk in European countries.

Staphylococcus aureus is globally one of the most important pathogens causing contagious mastitis in cattle. Previous studies, however, have demonstrated in Swiss cows that Staph. aureus isolated from bovine intramammary infection is genetically heterogeneous, with Staph. aureus genotype B (GTB) and GTC being the most prominent genotypes. In addition, Staph. aureus GTB was found to be contagious, whereas Staph. aureus GTC and all the remaining genotypes were involved in individual cow disease. The aim of this study was to subtype strains of Staph. aureus isolated from bovine mastitic milk and bulk tank milk to obtain a unified view of the presence of bovine staphylococcal subtypes in 12 European countries. A total of 456 strains of Staph. aureus were subjected to different typing methods: ribosomal spacer PCR, detection of enterotoxin genes, and detection of gene polymorphisms (lukE, coa). Major genotypes with their variants were combined into genotypic clusters (CL). This study revealed 5 major CL representing 76% of all strains and comprised CLB, CLC, CLF, CLI, and CLR. The clusters were characterized by the same genetic properties as the Swiss isolates, demonstrating high clonality of bovine Staph. aureus. Interestingly, CLB was situated in central Europe whereas the other CL were widely disseminated. The remaining 24% of the strains comprised 41 genotypes and variants, some of which (GTAM, GTBG) were restricted to certain countries; many others, however, were observed only once

The variation of stygofauna along a gradient of salinization in a coastal aquifer

We examined the variation of stygofauna composition collected in wells, along a gradient in groundwater salinity/conductivity in a coastal aquifer from southern Portugal. The studied coastal aquifer is considered vulnerable to salinization due to seawater intrusion, caused by overexploitation of the aquifer. Knowing the response of the stygofauna species to present levels of groundwater salinity makes it possible to understand and measure the effects of saltwater intrusion on stygofauna, rendering them potential bioindicators of this environmental pressure. Biotic and abiotic sampling was conducted in six shallow wells located in the fresh-saltwater interface of the Arade estuary along the salinity gradient established in the groundwater from the estuary to inland locations (microSiemens/cm). Groundwater salinity was highly correlated with taxa distribution. The stygobites Eucyclops hadjebensis and Acanthocyclops sensitivus, the cosmopolitan Megacyclops viridis and Cypria ophtalmica were particularly associated with low-salinity conditions, whereas Eucyclops graeteri, Megacyclops brachypus and Daphnia pulicaria were related to high-salinity waters. Multivariate analyses indicated that stygofauna assemblages varied significantly with location. We suggest that stygofauna composition and structure can be a useful complementing tool for monitoring seawater intrusion into coastal aquifers, where reduction or deterioration in groundwater resources is predicted