HOW CHICKEN MOVEMENT IS USED TO DETECT CAMPYLOBACTER-INFECTED FLOCK.

An Oxford team tested the hypothesis that flocks colonized with Campylobacter might be distinguishable by their behavior.This is based on suggestions that infection could have an impact on chickens' welfare. Professor Marian Dawkins, of Animal Behaviour at Oxford and corresponding author on the paper, said: "We used a novel and non-invasive way of monitoring the behavior of chickens throughout their lives that involved analyzing the optical flow patterns from cameras inside broiler houses. What is optical flow and how is it measured? Optical flow works by detecting the patterns formed by changes in brightness in moving images, both temporally and spatially.It is computationally simple and does not require tagging or marking individual animals, making it ideal for long-term continuous monitoring of large groups of similar animals such as egg-laying hens and broiler chickens, where optical flow is predictive of key welfare measures such as mortality rate. To test the hypothesis that optical flow analysis might also be able to detect when flocks become infected with Campylobacter, the researchers collected data for 31 commercial broiler flocks.They also collected faecal samples from those same flocks and tested them for the presence of Campylobacter at different ages (21 days, 28 days and 35 days) using standard laboratory methods. This gave a direct comparison between optical flow and testing from fecal samples. Campylobacter-positive flocks showed lower mean optical flow (less average movement) and higher kurtosis (less uniform movement) than flocks without the bacteria - as early as the first 10 days of life. Additionally, this link was independent of external temperature. Professor Dawkins said: "Our results provide statistical evidence of a link between broiler chicken flock behavior and Campylobacter status. excerpts from journal proceedings from Royal society B