2.1.4 Which factors influence the time of infection and the Ileitis ELISA-profile in European farms?

It can generally be assumed that farm related factors such as hygiene, biosecurity systems, feed, housing, population density and health management strategies will influence the preva­lence and severity of the disease (Bronsvoort et al. 2001; Stege et al. 2001; Hagen and Bilkei 2002). The following analysis of factors influ­encing the ELISA seroconversion is based on 126 German farm profiles. Table 2.1.4a gives an overview about the farm sizes and production level in 126 German farm. The average farm produced pigs with 393 sows – from as small as 60 sows to 2,700 sows and between 100 and 25,000 fattening places.

The average daily weight gain in the fattening period (755g) varied between 573g and 957g. The feeding system was mainly (78%) liquid feeding in fattening and dry feeding in nursery (64%). In 72% of the farms feed antibiotics were used in nursery and 52% of the farms used feed antibiotics in fattening. All in/all out during fattening was practised on more than 80% of the farms.

The farm size and production parameters are slightly above the mean generally seen in Europe but nevertheless representative for the farm types producing the majority of slaughtered pigs in Germany (Gatzka et al. 2002).

Table 2.1.4 a
Average size and production parameters of the 126 included farms in the Ileitis survey Germany.