Salinomycin Concentration in Eggs and Tissues of Laying Hens

The objective of our study was to monitor the presence of salinomycin in eggs and tissues of laying hens fed with rations containing 60 mg kg-1 salinomycin sodium for five days. Residues of salinomycin were determined on the day of withdrawal from salinomycin treatment in the breast and thigh muscle, liver, abdominal fat and ovarian yolk. In eggs, residues of salinomycin were monitored in both yolk and albumen daily from the beginning of treatment until the tenth day after withdrawal. Salinomycin was first found in yolk 1 day after starting the treatment and persisted for 8 days after withdrawal. The highest average level, 480 μg kg-1, was present on the third day after withdrawal. In albumen, levels of salinomycin residues were significantly lower, with a maximum level of 15 μg kg-1 reached on the fifth day of the experiment; and they were only found up to one day after withdrawal. Salinomycin was found in all ovarian yolks present in the body of layer hens in a concentration range between 237 and 553 μg kg-1. It was also found in the abdominal fat (concentration range from 62 to 237 μg kg-1) and the liver (concentration ≤ 10 μg kg-1), but not in breast or thigh muscle tissues. No changes in salinomycin residues were observed after cooking and frying the eggs

Possible sources and spreading routes of highly pathogenic avian influenza virus subtype H5N1 infections in poultry and wild birds in Central Europe in 2007 inferred through likelihood analyses.

Recurrent outbreaks of H5N1 HPAIV occurred in several Central European countries in 2007. In-depth phylogenetic analyses which included full-length genomic sequences of the viruses involved were performed to elucidate possible origins of incursions and transmission pathways. Tree reconstructions as well as host-shift and ancestral area inferences were conducted in a maximum likelihood framework. All viruses belonged to a separate subgroup (termed "EMA-3") within clade 2.2, and, thus, were distinct from two lineages of HPAIV H5N1 viruses (termed "EMA-1" and "EMA-2") present in the same geographic area in 2006. Analysis of concatenated coding regions of all eight genome segments significantly improved resolution and robustness of the reconstructed phylogenies as compared to single gene analyses. At the same time, the methodological limits to establish retrospectively transmission networks in a comparatively small geographic region and spanning a short period of time became evident when only few corroborating field-epidemiological data are available. Ambiguities remained concerning the origin of the EMA-3 viruses from a region covering Southeast Germany and the Czech Republic as well as routes of spread to other European countries. AIV monitoring programmes in place for wild birds and poultry in these countries did not reveal presence of these viruses in either population. Host switches between domestic poultry and wild bird populations occurred several times. Analysis of outbreaks in Northeast Germany and nearby Northern Poland in December 2007 demonstrated that geographic and even temporal vicinity of outbreaks does not necessarily indicate a common source of incursion