The negative correlation between fattening and laying performance prevents breeding improvement in both laying performance and meat yield. Therefore, specialized chicken lines have been bred in order to achieve either an efficient production of high-quality eggs or high growth rates. As a result, day-old male chicks are culled in the layer hatchery, which poses animal welfare and ethical problems. Breeding companies, scientific groups, and hatcheries are attempting to resolve this issue, with a common aim to find feasible alternatives for the routine killing of male layer chicks. Some approaches aim to influence the sex ratio, while others target at the economically feasible use of the male layer offspring, such as the fattening of "laying hen brothers" or crossbreedings of layers and broilers to create "dual-purpose chickens." Another approach is the sex determination prior to hatch. One of the prerequisites of in ovo sex determination is a practicable method that can be used in industry. The analysis needs to be rapid, cost-efficient, and highly precise; in addition, negative impacts on hatching rate, animal health, and/or performance parameters should be limited. Furthermore, sex determination should be performed before the sensory nervous system's response of the chick embryo to certain or potentially harmful stimuli is developed, which according to current knowledge is before the d 7 of incubation.

The aim of the study was to characterize atherosclerotic changes in African grey parrots (Psittacus erithacus) and Amazon parrots (Amazona spp.) by histochemical and immunohistochemical methods. Samples of the aorta ascendens and trunci brachiocephalici from 62 African grey parrots and 35 Amazon parrots were stained by hematoxylin and eosin and Elastica van Gieson for grading of atherosclerosis in these birds. Four different stages were differentiated. The incidence of atherosclerosis in the examined parrots was 91.9% in African grey parrots and 91.4% in Amazon parrots. To evaluate the pathogenesis in birds, immunohistochemical methods were performed to demonstrate lymphocytes, macrophages, smooth muscle cells, and chondroitin sulfate. According to the missing lymphocytes and macrophages and the absence of invasion and proliferation of smooth muscle cells in each atherosclerotic stage, "response-to-injury hypothesis" seems inapplicable in parrots. Additionally, we found alterations of vitally important organs (heart, lungs) significantly correlated with atherosclerosis of the aorta ascendens.

In order to provide an alternative to day-old chick culling in the layer hatcheries, a noninvasive method for egg sexing is required at an early stage of incubation before onset of embryo sensitivity. Fluorescence and Raman spectroscopy of blood offers the potential for precise and contactless in ovo sex determination of the domestic chicken (Gallus gallus f. dom.) eggs already during the fourth incubation day. However, such kind of optical spectroscopy requires a window in the egg shell, is thus invasive to the embryo and leads to decreased hatching rates. Here, we show that near infrared Raman and fluorescence spectroscopy can be performed on perfused extraembryonic vessels while leaving the inner egg shell membrane intact. Sparing the shell membrane makes the measurement minimally invasive, so that the sexing procedure does not affect hatching rates. We analyze the effect of the membrane above the vessels on fluorescence signal intensity and on Raman spectrum of blood, and propose a correction method to compensate for it. After compensation, we attain a correct sexing rate above 90% by applying supervised classification of spectra. Therefore, this approach offers the best premises towards practical deployment in the hatcheries.

Objective Pigeon rotavirus A (RVA) isolates of genotype G18P[17] are causing disease outbreaks and fatalities in pigeon lofts in Australia, Germany, Belgium, Denmark and USA since 2016. Most disease outbreaks have been reported from juvenile pigeons (Columba livia forma domestica). However, reports on RVA-associated disease outbreaks in fancy pigeons in connection with fancy pigeon shows in Germany are rare. Material and methods Overall 18 pigeons (16 fancy pigeons and one racing pigeon from 9 pigeon fanciers, as well as one feral pigeon from a rescue center) were sent in for routine diagnostic necropsy including histopathologic, parasitologic and microbiologic examinations. Molecular biologic examinations for detection of RVA, circovirus, Usutu virus, West Nile virus and Chlamydia psittaci were also carried out on all pigeons. An accompanying questionnaire filled in by the senders was used to generate basic information on the affected pigeon lofts. Results Disease outbreaks in juvenile and adult pigeons were reported 7–14 days after fancy pigeon shows. One fancier who had previously vaccinated his pigeons with an autogenous pigeon RVA vaccine, noted no morbidity and mortality among his pigeons and thus sent in a healthy pigeon for diagnostic purposes. Reported clinical signs in the other pigeons were regurgitation, green slimy diarrhea, anorexia, apathy and death after 24 hours. Hepatic necrosis and detection of pigeon RVA isolates of genotype G18P[17] confirmed disease outbreaks caused by pigeon RVA in all pigeons, except for the vaccinated pigeon. Besides pigeon circovirus, which was detected in 15 of 18 pigeons, all other pathogens were singular findings. Conclusion and clinical relevance In disease outbreaks following fancy pigeon shows in juvenile and adult pigeons diagnostics should include pigeon RVA of genotype G18P[17].

The keeping of backyard poultry and waterfowl as pets has become increasingly popular in recent years, resulting in a rising case load of these patients in veterinary practices. Diagnostic imaging techniques are taking a leading role in rapid diagnosis in the live bird. We provide an overview of the most important points regarding radiographic and ultrasonographic imaging procedures in these birds. We also review the most commonly documented radiographic and ultrasonographic signs in these species, as well as discuss unique anatomic characteristics with which the veterinarian should be familiar.