[Serological studies in wild boars in the Veluwe area].

In the second part of 1994, blood samples from 115 wild swine are tested for gE-antibodies to Aujeszky Disease Virus. Three of the blood samples reacted positive. The tests for Classical Swine Fever and for Swine Vesicular Disease were negative in all samples.

[Logbook registration in slaughtering pig farms within the project Integrated Quality Control. II. Drug utilization in relation to clinical observation, farm conditions and prevalence of pathological findings].

During an Integrated Quality Control (IQC) project for finishing pigs, the application of veterinary drugs was registered by means of a logbook on 75 pig finishing farms. Investigated is as to how far the application of veterinary drugs to animals is linked up with clinical observations, management and climatic conditions on the farm and to what extent the application of veterinary drugs is linked up with the occurrence of pathological findings in pigs at the slaughterhouse. The results indicate that more veterinary drugs are used as there are more clinical findings on a pig farm.

Variation in seropositivity for some respiratory disease agents in finishing pigs: epidemiological studies on some health parameters and farm and management conditions in the herds.

The relationship between the extent of seropositivity for Aujeszky's disease virus (ADV), Actinobacillus pleuropneumoniae (App.) serotype 2 and porcine influenza (PI) viruses serotype H1N1 and H3N2 in pigs on the one hand and the health status of the pigs and some farm and management conditions in the herds on the other hand was studied in 45 pig finishing herds, all members of one integration group. The health status was assessed by the extent of clinical signs, the use of veterinary drugs and the prevalence of pathological lesions in pigs at slaughter.

Sero-epidemiological screening of pig sera collected at the slaughterhouse to detect herds infected with Aujeszky's disease virus, porcine influenza virus and Actinobacillus (Haemophilus) pleuropneumoniae in the framework of an integrated quality control (IQC) system.

Over a period of six months, approximately 4700 blood samples were collected from 97 pig-finishing farms in the provinces of Noord-Brabant and Gelderland and screened for antibodies with respect to Aujeszky's disease virus (ADV), porcine influenza virus (PI) and Actinobacillus (Haemophilus) pleuropneumoniae (App). There were significant differences in the percentages of seropositive pigs between the two provinces, which may be related to the difference in the density of the pig population in the two provinces. In practice, it was possible to perform a reliable sera collecting procedure at the slaughterhouse.

[Log book registration of farms for slaughtering pigs in the Integrated Quality Control Project. I. Use of drugs and vaccines].

Log book recording was done for twelve months on approximately 100 pig finishing farms in an Integrated Quality Control (IQC) project. This recording was designed to gain a better understanding of the extent and nature of the medication and vaccination on these farms. Vaccination against Aujeszky's disease was done on the majority of farms.

[Streptococcus suis type 2 in swine. An imported problem?].

Investigations were carried out on eighteen farms in the Province of Gelderland to determine whether it was possible to use biopsy specimens of the tonsils to differentiate between farms with clinical problems caused by Streptococcus suis type 2 and farms without these problems. The proportion of carriers of this organism on the farms was 14 per cent and 2 per cent respectively, so that this differentiation is feasible. It was also studied whether this proportion differed on farms which imported pigs from Great Britain and farms which did not do so; the proportion of carriers on farms having animals imported from Great Britain was found to be higher than that on farms not using these importations, viz.