Application of wireless electroencephalogram (EEG) to measure stress in ducks

Animal welfare and public perception of animal welfare is guiding animal agriculture, practices and policies. Producers are faced with the challenge of improving production efficiency and meeting environmental and animal welfare restrictions. Many of the current measures of assessment of animal welfare are qualitative rather than quantitative. The objective of this study is to develop and evaluate quantitative measures to directly measure stress through evaluation of brain activity using electroencephalography (EEG). Two experiments were performed to develop and validate EEG as a tool for assessing poultry welfare. In Experiments 1 and 2, White Pekin ducks were treated with known stressors including auditory, mild electric stimuli, and changes in the microenvironment (i.e. exposure to ammonia). In Experiment 1, 16 (5-10 wk) White Pekin ducks were implanted with EEG transmitters and sensing electrodes positioned on the surface of the telencephalon. Each bird was individually placed in a controlled chamber and treated with one of the above stressors while being monitored during a 15 minute (900 s) trial. In Experiment 2, 8 (5-10 wk) White Pekin ducks were treated the same as in Experiment 1 but with an extended observation time of 45 minutes (2700 s). After treatment with one of the three stressors, auditory, mild electrical stimuli, or ammonia, EEG files were analyzed both on a raw and frequency domain basis for identifiable signs. EEG analysis for Experiment 1 showed no differences between time periods for all frequencies. Experiment 2 ECG results showed no differences between time periods for all treatments. Experiment 2 corticosterone results showed differences between pre-treatment and post-treatment; however, there were no differences between treatments and no differences between treatments and control.