Preliminary study: Health and performance assessment in broiler chicks following application of six different hatching egg disinfection protocols.

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.

This method comparison study used radiographs of 20 mice and 20 budgerigars to investigate comparability between computed radiography (CR) and high-resolution screen-film systems and study the effects of reduced radiation doses on image quality of digital radiographs of small patients. Exposure settings used with the mammography screen-film system (SF) were taken as baseline settings. A powder-based storage-phosphor system (CR P ) and a needle-based storage-phosphor system (CR N ) were used with the same settings (D/100%) and half the detector dose (D/50%). Using a scoring system four reviewers assessed five criteria per species covering soft tissue and bone structures. Results were evaluated for differences between reviewers (interobserver variability), systems and settings (intersystem variability, using visual grading characteristic analysis). Correlations were significant (p ≤ 0.05) for interobserver variability in 86.7% of the cases. Correlation coefficients ranged from 0.206 to 0.772. For mice and budgerigars, the CR N system was rated as superior to the SF and CR P system for most criteria, being significant in two cases each. Comparing the SF and CR P system, the conventional method scored higher for all criteria, in one case significantly. For both species and both digital systems, dose reduction to 50% resulted in significantly worse scores for most criteria. In summary, the needle-based storage-phosphor technique proved to be superior compared to the conventional storage-phosphor and mammography screen-film system. Needle-based detector systems are suitable substitutes for high-resolution screen–film systems when performing diagnostic imaging of small patients. Dose reduction to 50% of the corresponding dose needed in high-resolution film-screen systems cannot be recommended.

Hatching egg disinfection, as part of the quality assurance system, is a standard procedure in commercial hatcheries. Formaldehyde was and is broadly used but bears high risks for the personnel. In preliminary studies, the spray application of hydrogen peroxide was successfully tested and was chosen to compare its efficacy and impact on hatchability, as well as performance during fattening, and at slaughter, to formaldehyde under field conditions. The trial was set up with hatching eggs from two breeder flocks, running parallelly in three groups (H2O2, formaldehyde and non-disinfected control) at four different flock ages (at 38, 39, 56, 57 weeks). No significant differences were noticed in the hatchery, whereas in the rearing period higher 7-day- and total mortalities occurred during trials 1 and 2 in all non-disinfected groups and one formaldehyde-treated group, making an antibiotic treatment necessary. At slaughter, the findings in all groups were comparable. Trials 3 and 4 passed without significant differences between all groups, leading to the conclusion that hatching egg disinfection lowers the risk of infection-related losses. Meanwhile, formaldehyde fumigation and the spraying of hydrogen peroxide produced similar results in all stages.

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 CRP, 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.