This study used data of farm-level technical and economic
factors to obtain insight into factors that might
be associated with the use of antibiotics on pig farms in
the Netherlands. The data set included pig farms that
take part in LEI FADN data collection as well as additional
data collection on animal medicines, with LEI
FADN farms considered representative for all farms in
the Netherlands. Based on the 2 selected sets of farm
factors, the study (sub)sample was representative for
the entire LEI FADN sample of pig farms. The main
advantage of this study is that it used real-life data collected
on private farms, mostly based on farm accounts,
and thus not subject to recording bias.
Antibiotics vary in their potency and pharmokinetic
properties, and this is manifested in varying dosages
per kilogram of BW. The measurement unit used in
this study, NDDi, is suitable for calculating total exposure
of pigs to different antibiotics, and making comparisons,
for example, between groups of pigs. This unit
conforms to international developments in this field
and developments in the human sector (Mevius et al.,
2007). Other measurement units to quantify antibiotic
usage, such as number of treatment days or associated
costs, are used. Different measurement units hav