Investigation into Broiler Production Systems: On-farm studies of how production systems, bird welfare and endemic disease affect the susceptibility of chickens to Campylobacter

Introduction

Campylobacter spp. are the most commonly reported bacterial food-borne pathogens in Europe. Transmission is strongly associated with consumption of undercooked poultry products. The UK rears >850 million broiler chickens for meat consumption annually. Standard production systems (STD) constitute approximately 90% of production and use birds reaching slaughter weight at 35-39 days. Higher welfare (HW) systems account for the remaining 10% and typically use slower-growing breeds with lower stocking densities and are housed in houses with windows and environmental enrichment, however faster growing breeds are also grown under such systems.Previous work found that HW flocks have lower levels of Campylobacter and reduced incidence of welfare-associated pathologies.

Project overview

  • We will investigate Campylobacter in commercial broiler systems to identify management options to better control colonisation and extra-intestinal spread of these bacteria. We are working with the major UK chicken producers in a combined field, laboratory and modelling study.

Retrospective data analysis of Campylobacter risk factors at the flock level in these systems.

Longitudinal Field studies of within flock dynamics of Campylobacter colonisation and extra-intestinal spread.

Laboratory studies: Bird genotype and susceptibility to Avian Pathogenic E.coli (APEC) and Campylobacter and mechanisms of its extra-intestinal spread.

The field hypotheses will be tested under controlled laboratory conditions and provide parameter estimates for the modelling of interventions.

Project Aims

The work conducted as part of this project will provide information on the mechanistic basis for different responses to Campylobacter between fast and slow growing broiler breeds. This information can be used to inform observations derived from on-farm studies and for use in mathematical models.

 Our research questions are:

  • Are there inherent differences in susceptibility to Campylobacter infection between different (fast and slow growing) broiler lines?
  • Do different broiler lines exhibit different immunological responses to Campylobacter infection?
  • Does an interaction in the gut between Campylobacter and the endemic disease agent Avian Pathogenic E. coli (APEC) contribute to spread of Campylobacter?
  • Does stocking density influence colonisation with Campylobacter and/or APEC in the different broiler lines?

Key Hypotheses

  • Broiler production systems (STD/HW) affect bird welfare and the house environment; these factors interact to determine susceptibility of birds to Campylobacter colonisation.
  • Broiler production systems influence the occurrence of endemic disease (specifically APEC) which in turn impacts on the colonisation of Campylobacter in birds.

 Broiler Production Systems Diagram