For this project, 16 laying hens were individually trained to distingush between two different quantities of a food reward placed in different sized, different coloured bowls. The hens were then trained to perform a T-maze choice test which set up can be seen in the picture to the right. The hen were placed in the start box, located in the middle of the maze, and were then presented with the options on either sides of the maze. Therefore, the hen was allowed to make a decision before the opening of the tunnel door which allowed her to reach her chosen option. 

The hens were tested making two different types of decisions. What here was defined as an easy decision was a choice between two unbalance options (large vs. small reward). On the other hand, the difficult decision was defined as a choice between two balanced options. To create a balance between these options, a cost (weighted push doors) was added to reach the large reward causing the small reward to be chosen approximately as often as the large reward.

The hens were tested making both easy and difficult decision, with or without prior stress treatment. They were stressed using mild physical restraint where the hen was placed in a free hanging net for 5 minutes directly prior to being tested.

Data Collection

• Choices made - if the hen chose the large or the small reward
• Latency - the time it took for the hen to reach her chosen option
• Heart Rate - the hens heart rate was measured using a heart rate monitor which were carried by the hen in a harness
• Thermal Images - comb, eye and head temperatures were measured using a thermal imaging camera while the hen was in the start box