The overall objective of this project is to draft an (enhanced) biosecurity protocol, efficient but also easily implementable to reduce the risk that broiler flocks become colonized with Campylobacter. In order to do so, following specific research questions will be answered:

1. "What are possible risk factors for the introduction of Campylobacter in broiler flocks in Belgium?" No risk analysis will be carried out as risk factors are already identified in several recent European studies. However, these risk factors will be listed and discussed with people
working in the broiler production sector.
2. "Are these identified risk factors for Campylobacter introduction identical or complementary to the contamination sources identified by a longitudinal molecular epidemiological study?" To do so, 60 broiler flocks (from 15 farms) will be sampled and both cecal droppings from the
broilers and possible risk factors will be sampled. Isolated campylobacters will be characterized to identify contamination routes and sources. This should lead to an (enhanced) biosecurity protocol that reduces the risk of Campylobacter introduction on broiler farms.
3. Is it possible to reduce Campylobacter colonization in broilers flocks when a strict biosecurity protocol is followed?" On the same farms, this biosecurity protocol will be implemented and evaluated.
4. "What is the difference in the microbiota of broilers which remain Campylobacter free until slaughter with the microbiota of flocks which become or are colonized with Campylobacter?" To answer this research question, cecal droppings collected in the first research part will be
analyzed in order to determine the difference in the bacterial composition.