Objective The use of low-energy electron irradiation for hatching egg disinfection was compared to formaldehyde fumigation. Material and methods To assess the efficacy, eggshells were examined for bacteria before and after disinfection. During incubation, hatching and fattening of 1400 Ross 308 broilers per group candling data, hatching rate, mortality rate and body mass development were recorded to evaluate the impact on health and performance. Additionally, data from the slaughter house and histological evaluation of organ samples were included in the health screening. Results Regarding the efficacy, irradiation and formaldehyde significantly reduced the number of bacteria compared to non-disinfected eggs. However, no significant difference was recorded between both treatments. The irradiated group performed better than the reference group concerning the number of infertile eggs, early and late dead embryos and fertile eggs. The performance during fattening was nearly identical in both groups, while mortality differed slightly between the irradiated group and the group treated with formaldehyde. Upon slaughter, there were minor variations concerning the distribution of findings between the groups, but the number of anomalies was not higher than reference values suggest. Conclusion In both groups no health problems were observed during rearing and the fattening performance met the targets of the manufacturer Aviagen for the used broiler line Ross 308. Clinical relevance Lower-energy electron irradiation proves to be an efficient and well-tolerated hatching egg disinfection procedure. Further field trials are necessary to establish low-energy electron irradiation as an alternative to formaldehyde fumigation. Gegenstand und Ziel Der Einsatz niedrigenergetischer Elektronenstrahlung zur Bruteidesinfektion wurde mit dem Verfahren der Formaldehydbegasung verglichen. Material und Methoden Zur Beurteilung der Effizienz wurden Eierschalen vor und nach Desinfektion auf Bakterien untersucht. Während Brut, Schlupf und Mast von 1400 Ross-308-Broilerküken pro Gruppe wurden Daten vom Schieren, Schlupfrate, Mortalitätsrate und Gewichtszunahmen erfasst, um den Einfluss auf Tiergesundheit und Mastleistung zu überprüfen. Zusätzlich wurden am Schlachthof erfasste Daten sowie Ergebnisse der histologischen Untersuchung von Organproben in die Gesundheitsüberprüfung einbezogen. Ergebnisse Sowohl durch Elektronenstrahlung als auch durch Formaldehydbegasung ließ sich die Anzahl an Bakterien auf der Eioberfläche im Vergleich zu nicht desinfizierten Eiern signifikant verringern. Ein signifikanter Unterschied zwischen den beiden Verfahren bestand nicht. Die mit Elektronenstrahlung behandelte Gruppe zeigte beim Schieren bessere Werte bezüglich der Anzahl unbefruchteter Eier, abgestorbener Embryonen und befruchteter Eier als die mit Formaldehyd behandelte Gruppe. Die Tageszunahmen und das Mastendgewicht waren in beiden Gruppen fast identisch, während die Mortalitätsrate leicht differierte. Bei der Schlachtung gab es Varianzen im Hinblick auf die Verteilung von Schlachtbefunden, doch war die Anzahl auffälliger Tierkörper nicht höher, als Referenzen es vermuten lassen. Schlussfolgerung In beiden Gruppen wurden im Verlauf der Aufzucht keine Gesundheitsprobleme beobachtet und die Mastleistung entspach den Zielvorgaben des Herstellers Aviagen für die verwendete Broilerlinie Ross 308. Klinische Relevanz Niedrigenergetische Elektronenstrahlung erweist sich als ein wirksames und verträgliches Verfahren zur Bruteidesinfektion. Es sind weitere Feldversuche nötig, um das Verfahren als Alternative zur Formaldehydbegasung zu etablieren. Received: 13 May 2020 Accepted: 20 August 2020 Publication Date: 04 December 2020 (online) © 2020. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Three different digital detector systems were used to study the effect of a defined radiation dose reduction on the image quality of digital radiographs in bearded dragons (Pogona vitticeps). A series of radiographs of seven bearded-dragon cadavers with a body mass ranging from 132 g to 499 g were taken in dorsoventral projection. The digital systems employed included two computed radiography systems (CR) (one system with a needle-based and one with a powdered-based scintillator) and one direct radiography system (DR). Three levels of the detector dose were selected: A standard dose (defined based on the recommended exposure value of the CR_P, D/100%), a half dose (D/50%), and a quarter dose (D/25%). Four image criteria and one overall assessment were defined for each of four anatomic skeletal regions (femur, rib, vertebra, and phalanx) and evaluated blinded by four veterinarians using a predefined scoring system. The results were assessed for differences between reviewers (interobserver variability), radiography systems, and dosage settings (intersystem variability). The comparison of the ratings was based on visual grading characteristic (VGC) analysis. Dose reduction led to significantly lower scores in all criteria by every reviewer, indicating a linear impairment of image quality in different skeletal structures in bearded dragons. Scores did not differ significantly between the different systems used, indicating no advantage in using a computed or direct radiography system to evaluate skeletal structures in bearded dragons. The correlation was significant (p ≤ 0.05) for interobserver variability in 100% of the cases, with correlation coefficients between 0.50 and 0.59. While demonstrating the efficacy of the use of digital radiography in bearded dragons and the similar quality in using different computed or direct radiography systems, this study also highlights the importance of the appropriate level of detector dose and demonstrates the limits of post-processing algorithm to compensate for insufficient radiation doses in bearded dragons.