Mortality in organic free-range chickens and molecular characterization of the involved pathogens

Longitudinal investigations on causes of mortality were carried out at one organic layer farm with four flocks of Lohman Brown and Lohman White chickens producing table eggs. All flocks were housed separately. One flock of each breed were followed from September 2001 to August 2002. Post mortem examinations were performed on a total of 16% of the dead chickens over the entire period. Of these 346 (96%) of the Lohmann Brown and 315 (91%) of the Lohmann White chickens were subjected for bacteriology. High mortality rates, 91% and 63% were observed in Lohman Brown and Lohman White chickens, respectively and were found to be due to infections with mainly Pasteurella multocida, Erysipelothix rhusiopathia and Escherichia coli. E. rhusiopathia, P. multocida and E. coli were isolated from 46%, 19% and 17%, respectively of the Lohmann Brown chickens. In the flock of Lohmann White chickens P. multocida and E. coli were isolated from 46% and 15%, respectively while E. rhusiopathia was not recorded. P. multocida and E. rhusiopathia isolates were characterized by Restriction Endonuclease Analysis (REA), Restriction Fragment Length Polymorphism (RFLP) and Pulse Field Gel Electrophoresis (PFGE). It was demonstrated that all the P. multocida isolates were genotypic identical over time. The E. rhusiopathia isolates obtained were also identical. It was concluded that the outbreaks caused by P. multocida and E. rhusiopathia were clonal and these two pathogens may cause severe losses in free-range chickens

Potential of a cyclone prototype spacer to improve in vitro dry powder delivery

Copyright The Author(s) 2013. This article is published with open access at Springerlink.com. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are creditedPurpose: Low inspiratory force in patients with lung disease is associated with poor deagglomeration and high throat deposition when using dry powder inhalers (DPIs). The potential of two reverse flow cyclone prototypes as spacers for commercial carrierbased DPIs was investigated. Methods: Cyclohaler®, Accuhaler® and Easyhaler® were tested with and without the spacers between 30-60 Lmin-1. Deposition of particles in the next generation impactor and within the devices was determined by high performance liquid chromatography. Results: Reduced induction port deposition of the emitted particles from the cyclones was observed due to the high retention of the drug within the spacers (e.g. salbutamol sulphate (SS): 67.89 ± 6.51 % at 30 Lmin-1 in Cheng 1). Fine particle fractions of aerosol as emitted from the cyclones were substantially higher than the DPIs alone. Moreover, the aerodynamic diameters of particles emitted from the cyclones were halved compared to the DPIs alone (e.g. SS from the Cyclohaler® at 4 kPa: 1.08 ± 0.05 μm vs. 3.00 ± 0.12 μm, with and without Cheng 2, respectively) and unaltered with increased flow rates. Conclusion: This work has shown the potential of employing a cyclone spacer for commercial carrier-based DPIs to improve inhaled drug delivery.Peer reviewe

Sygdomme og velfærd

Siden anden verdenskrig er der sket store ændringer i fjerkræproduktionen. Indførslen af nye produktionssystemer, robuste og højtydende dyr, forbedret management og indførslen af biosecurity har medført en stor produktionsfremgang med lav mortalitet. I de senere år har forbrugerønsker medført at udvikling af udendørs produktionssystemer, hvor de klassiske fjerkræsygdomme nu er på fremmarch med en forhøjet mortalitet til følge. Forfatterne diskuterer, om de udendørs produktionssystemer reelt har betydet en forbedret velfærd for hønerne

Influence of molecular symmetry on strong-field ionization: Studies on ethylene, benzene, fluorobenzene, and chlorofluorobenzene

Using the molecular strong-field approximation we consider the effects of molecular symmetry on the ionization of molecules by a strong, linearly polarized laser pulse. Electron angular distributions and total ionization yields are calculated as a function of the relative orientation between the molecule and the laser polarization. Our studies focus on ethylene (C$_2$H$_4$), benzene (C$_6$H$_6$), fluorobenzene (C$_6$H$_5$F), and ortho chlorofluorobenzene (1,2 C$_6$H$_4$ClF), the molecules representing four different point groups. The results are compared with experiments, when available, and with the molecular tunneling theory appropriately extended to non-linear polyatomic molecules. Our investigations show that the orientational dependence of ionization yields is primarily determined by the nodal surface structure of the molecular orbitals.Comment: 13 pages, 10 figures. Submitted to Physical Review

The effect of concurrent infections with Pasteurella multocida and Ascaridia galli on free range chickens

Pasteurella multocida and Ascaridia galli are observed with high prevalences in free range chickens in Denmark, but the impact is unknown. A study was carried out to examine the interaction between A. galli and P. multocida in chickens and the impact on production. Five groups, each with 20 18-week-old Lohmann Brown chickens were infected. Group I was orally infected with 1000 +/- 50 embryonated A. galli eggs. Group 2 received 10(4) cfu p. multocida intratracheally. Group 3 was infected with A. galli and subsequently with P. multocida. Group 4 was infected with P. multocida followed by A. galli. Group 5 was the control. The study ran for I I weeks where clinical manifestations, weight gain and egg production were recorded. Excretion of P. multocida was determined on individual basis and blood smears were made for differential counts. At the end of the study pathological lesions and the number of adult worms, larvae and eggs in the faeces were recorded. The birds were more severely affected when infected with both pathogens compared to single infections with A. galli or P. multocida, respectively. A lower weight gain and egg production was observed with dual infections. A. galli infection followed by a secondary P. multocida infection resulted in more birds with pathological lesions and continued P. multocida excretion. In conclusion a negative interaction between A. galli and R multocida was observed and it is postulated that free range chickens are at higher risk of being subjected to outbreaks of fowl cholera when they are infected with A. galli