The effect of incorporation of species-specific anti-immunoglobulin G (anti-IgG) antisera into the haemagglutination-inhibition (HI) test for antibodies to Newcastle disease viruses (NDV) was investigated. Experiments were made on the specificity of the rise in titre and on the reproducibility of results, and routine examinations of sera were carried out. A special object was to scrutinize the specificity of low titres in conventional tests and to investigate the possibility of eliciting measurable titres from sera negative by conventional methods by adding anti-IgG. Despite the good accuracy and the acceptable reproducibility of the anti-immunoglobulin G haemagglutination-inhibition test, only 66% of sera positive in conventional haemagglutination-inhibition test yielded a rise of titres. Neither age nor 2-mercaptoethanol-sensitivity of haemagglutination-inhibiting antibodies seemed to be responsible for this property. A possible reason why not every serum that is positive in the normal test shows an increase in titre might be the physico-chemical properties of avian antiviral sera or immunoglobulins. The findings did not achieve the expectations mentioned earlier. If it were possible, however, to determine the reasons for the differences in the behaviour of NDV-antisera, the anti-IgG test could be of value in the understanding of the HI-test and for the further study of Newcastle disease serology.

Ceruloplasmin (Cp) plays an important role in copper transport and iron metabolism, as well as Cp is also an indicator for the health status of dairy cows. The present study reports the validation of an automated assay to assess the plasma Cp in dairy cows. Plasma Cp levels were determined in 40 Holstein cows and intra- and inter-assay precision, accuracy, detection limit, and clinical validation of the assay were determined. Intra- and inter-assay coefficients of variation were < 2% and < 7%, respectively. The results were linear when serial sample dilutions were tested ( r = 0.999, P < 0.001). The detection limit was lower than what could be measured in plasma from healthy cows. Increased plasma Cp levels were found in cows with inflammatory diseases. The method validated in this study is precise, simple, and fast and can be easily adapted to biochemical automated analysers. Furthermore, the promising results obtained with this protein will contribute to a wider use of Cp determination in bovine practice. Electronic supplementary material The online version of this article (10.1186/s13028-019-0470-4) contains supplementary material, which is available to authorized users.

Following maternal chicken pox in the 14th week of pregnancy, a male infant was born with low birth weight, muscle wasting and limb contractures, hypotonia and areflexia. A rising titre of varicella-zoster-specific IgM (by enzyme-linked immunoabsorbent assay) confirmed congenital infection, and electromyogram showed widespread denervation. Death occurred at 8 days. Neuropathological examination revealed destructive and inflammatory lesions of cerebral cortex and white matter, thalamus, brain stem and spinal cord. In addition there were cerebellar heterotopias and bilateral polymicrogryic malformations of the insular cortex.

Summary Dust vaccine against Newcastle disease with defatted milk powder as an excipient gives similar titre production in 4 to 5 weeks old SPF chickens as drinking water vaccine. The vaccine powder is very stable at +4 °C and — 30 °C with only a slight loss of virus titre within three years of storage. Dust vaccination by powdering vaccine upon food should not replace drinking water immunization under normal conditions. Only in conditions of poor hygiene of the water supply or in vaccination of few animals, can dust‐vaccine offer advantages because of its stability and the possibility of accurate dosage. Zusammenfassung Eine Alternativmethode bei der Newcastle‐Prophylaxe, die Impfstoff‐Applikation in Pulverform Untersuchungen mit einer pulverisierten ND‐Vakzine, die mit Magermilch als Trägersubstanz hergestellt wurde, erbrachten bei 4 bis 5 Wochen alten SPF‐Tieren gegenüber der Trinkwasservakzination vergleichbare Antikörpertiter. Die verwendete Vakzine zeichnet sich durch große Haltbarkeit bei —30 °C aus, und auch bei +4 °C war nach fast dreijähriger Lagerung nur ein geringer Titerverlust feststellbar. Es werden Vorteile gegenüber der Sprayvakzination diskutiert und die Anwendung in kleinen Geflügelbeständen bzw. in Betrieben mit hygienisch nicht optimaler Trinkwasserversorgung vorgeschlagen.