ABSTRACT: The aim of this study was to investigate
farm-level economic and technical factors that are associated
with the use of antibiotics on pig farms. Identification
of such factors, like farm size and net farm
result, may help to increase epidemiological knowledge
and to specify farm advice and policy making to reduce
inappropriate use of antibiotics. The study used over
300 farm-year records collected during 2004 to 2007
from pig farms in the Netherlands. Data included economic
and technical factors as well as antibiotic administration.
Data were statistically analyzed for factors
associated with antibiotic use, both for fattening pig
and sow farms (piglets only), separately. The response
variable was the average number of daily dosages per
average pig year. Statistical analysis was performed on
16 and 19 potential explanatory factors for the fattening
pig and sow farms, respectively. The results showed
that, both on the fattening pig and sow farms, the average
use of antibiotics increased from 2004 to 2006, but
decreased during 2007, but the effect of year was not
significant (P > 0.05). Use of antibiotics varied between
individual farms. Large farm repeatability for the use
of antibiotics in the different years was found. Factors
associated (P < 0.05) with the use of antibiotics included:
farm system, number of pigs, and population
density in the region of the farm (for sow farms only).
As these factors are easy to collect and to register, they
can be used to specify farm advice and investigation, as
well as for policy making. The majority of the technical
and economic factors were not significantly (P > 0.05)
related to the on-farm use of antibiotics. Therefore, it is
recommended to focus future research on the potential
role of socioeconomic factors associated with antibiotic
use on pig farms.