PIG HEALTH AND PRODUCTION SURVEILLANCE IN DENMARK - SAMPLING DESIGN, DATA RECORDING, AND MEASURES OF DISEASE FREQUENCY

The Danish Swine Efficiency Control System and the Danish Pig Health Scheme are presented as the historical background for a 3 year pilot project called the Health and Production Surveillance system (HEPS). The overall objective of HEPS (launched in 1989) was to provide pig producers, their advisors, and other people associated with the pig industry with information about production performance, disease occurrence, and the impact of disease at the herd and national levels. This paper presents the sampling design, data recording and measures of disease frequency at the national level. The HEPS database includes information about production, clinical disease occurrence and routine veterinary slaughter inspection findings. All data concerning production and clinical disease were producer-recorded, while carcass lesions were recorded by meat inspectors at the abattoirs. A three-digit hierarchical disease coding system was designed for classification of clinical disease, mortality and culling reason. Disease frequency was measured on a daily basis. Smoothed estimates of the instantaneous incidence density showed that the most frequent diseases were: among sows, reproductive problems at farrowing (incidence 1.5 per 1000 sow-days); among non-weaned piglets, gastrointestinal diseases (incidence 0.8 per 100 piglet-days) and mortality (incidence 0.3 per 100 piglet-days); among fatteners, respiratory diseases (incidence 4 per 1000 fattener-days).