Integrated quality control project: Relationships between pathological findings detected at the slaughterhouse and information gathered in a veterinary health scheme at pig farms

Summary

In September 1986 an Integrated Quality Control Project (IQC) was started in the Netherlands. Over a period of 2 years a veterinary herd health scheme was applied to 21 growing and finishing pig herds. Information was collected concerning medical treatment, classified as group treatment and individual treatment, clinical observations, and housing factors. The main purpose of this project was to investigate relationships between pathological findings detected at the slaughterhouse and information gathered on the farm.

Medical group treatments, clinical observations and housing did not reliably predict pathological findings. Individual medical treatment for respiratory disorders, started in the last 30 days before slaughter, proved to be positively related to the the pathological findings ‘pneumonia’ and ‘pleuritis’ detected at the slaughterhouse. This may be useful for selecting pigs at the slaughterhouse that will require special treatment for the removal of the pleura parietalis.

During the first year of the project the average daily gain (ADG) was 27.2 g. more than during the preceding 2 years (P<0.0001). Coughing was negatively related with the ADG. More than 75 coughs per compartment during 10 minutes, recorded more than 50 days before slaughter, was positively related to a depression of the ADG (20 g; P<0.05).

Relationships between group medical treatments and ADG were statistically significant, when the group medical treatment was started more than 20 days before slaughter. Negative influences on the ADG were higher if the treatment was started closer to the slaughter date. Disregarding the reason for medical treatment, the depression of the ADG amounted to 23.8, 11.3, 3.9 and ‐5.9 g per day for intervals between medical treatment and slaughter of 21–40, 41–60, 61–80 and 81–100 days, respectively.

Blood samples were taken at slaughter from 20% of the slaughtered pigs. A total of 2039 blood samples were serologically tested for antibodies against Actinobacillus pleuropneumoniae (type 2 and 9) and influenza virus (type H1N1 and H3N2). Blood samples from pigs from all the farms showed antibodies against influenza H1M1, pigs from 95% of the farms had positive blood samples for Actinobacillus pleuropneumoniae type 2 and 9, while pigs from 86% of the farms had positive blood samples for Influenza H3N2.

Notes

Department of Herd Health and Reproduction Faculty of Veterinary Medicine, Utrecht University, the Netherlands.

Present: Salvay Duphar B. V., Weesp, the Netherlands.

Correspondence author.

Additional information

Notes on contributors

G.H.M. Blocks

1 2

J.H.M. Verheijden

1 3