Cadmium, zinc, lead, and copper in livers and kidneys of cattle in the neighbourhood of zinc refineries.

Cattle in the Kempen area (in the province North-Brabant, the Netherlands) were investigated for cadmium, lead, zinc, and copper in livers and kidneys. The animals originated from farms located within a 20 km radius around several zinc refinery plants. The local soil is polluted with zinc and cadmium because of a thermal refining process used in the past.Mean cadmium organ concentrations were 2.5 times, and mean lead organ concentrations were 1.5 times higher than the concentrations found in controls. Copper levels tended to be decreased, but zinc levels did not differ from controls.The observed cadmium and lead organ concentrations did not indicate intoxication of the animals, but 22% of the kidneys and 3% of the livers investigated trespassed the maximum tolerance limit of cadmium with regard to human consumption.Continuous control of cadmium organ contents in organs from slaughtercattle kept in cadmium-polluted areas is recommended.

[Aujeszky's disease: serological responsiveness after vaccination of 6-10-week-old piglets with maternal antibody (author's transl)]. / Ziekte van Aujeszky: entbaarheid van biggen met maternale antistoffen op een leeftijd van 6-10 weken.

Trials were made to study the extent to which 6-10-week-old piglets with and without virus-neutralizing (VN) antibodies are capable of a serological response to vaccination. The piglets were inoculated with three different vaccines: two live vaccines (Aescovac Aujeszky and MK25 vaccine) and an inactivated vaccine (Geskyvac). The titre of virus-neutralizing antibody in the blood was determined for each vaccine in approximately 200 piglets at the time of inoculation as well as within four and twelve weeks after inoculation. The maternal antibodies present at the time of inoculation were found to have an inhibitory action on the serological response following inoculation. Of those piglets in which a maternal VN titre was observed using the above technique, only 9 per cent showed an increase in titre after inoculation. This proportion was 74 per cent in the serologically negative piglets. Marked variations in serological response to the different vaccines were observed. the most positive response was that induced by Aescovac. There was an obvious relationship between the VN titre following inoculation and immunity against intracerebral challenge with 2,000 TCID50 of Aujeszky disease virus. Animals showing titres of 1:4 or over were immune to this challenge.

[Aujeszky's disease: maternal immunity of piglets born of sows inoculated with various vaccines (author's transl)]. / Ziekte van Aujeszky: maternale immuniteit van biggen, geboren uit met verschillende entstoffen geënte zeugen.

Studies on the maternal state of immunity were done in 4-10 week-old piglets born of vaccinated sows free from Aujeszky's disease. The sows were inoculated with three different vaccines: two live vaccines (Aescovac Aujeszky) and the MK25 vaccine) and an inactivated vaccine (Geskyvac). The maternal state of immunity of the piglets was assessed from the titre of the virus-neutralizing (VN) antibodies in the blood. To do so, samples were taken from 300-400 4-10-week-old piglets per vaccine inoculated in the sow. At the same time, the VN titre of the blood of the sow was determined. The VN titres were highest in those sows which were vaccinated with Geskyvac. There was an obvious correlation between the VN titre of the sow and the maternal VN titres of the piglets. As a result, the maternal state of immunity in the sows vaccinated with Geskyvac also was highest. The value of the maternal VN titres in the assessment of maternal immunity was tested by exposing 28-37-day-old piglets showing various maternal VN titres to intracerebral challenge with 2000 TCID50 of Aujeszky disease virus (Van Doorn strain). Piglets showing VN titres higher than 1:8 were usually found to be immune against this challenge.