Head, Eye and Comb temperature changes in Chooks during handling: the use of infrared thermal imaging in observing stress in chooks.

Abstract

It is now widely accepted in the scientific community that animals suffer from both physical and emotional stress. Emotional stress has been linked to an increase in core body temperature and decrease in surface area temperature of at least 0.5 degrees Celsius in a wide number of species, a phenomenon known as Stress-Induced hyperthermia (SIH) (Edgar et al, 2013). Catching and handling are relevant events in an animals life. Wild prey animal’s experience catching and handling by predators while animals raised for productivity experience catching and handling by Humans. Handling has been linked to the onset of stress-induced hyperthermia in many species, and Edgar et al (2013) provided evidence that handling causes a significant decrease in Head, Eye and Comb temperatures in Hens. The aim of this current research was to replicate that of Edgar et al (2013). This research aims to use infrared thermography to measure changes in Chooks Head, Eye and Comb prior to, during and after capture and handling. It is the hope that this research will provide further evidence that handling causes stress-induced hyperthermia in Hens. Infrared thermal imaging is a non-invasive measure of surface temperatures. It is the hope that this research will provide evidence that infrared thermography is an effective non-invasive measure useful in animal welfare research. 13 Hens and 6 Roosters Head, Eye and Comb temperatures were measured using infrared thermal imaging during 20 minute pre measurement, handling (capture by a researcher and held for 5 seconds) and 20 minute post measurement periods. Average surface area temperatures for each of the 19 subjects were obtained every minute during pre-measurement, handling and post-measurement. Average temperatures were plotted and analysed to investigate any patterns of change. Subjects Head, Eye and Comb temperatures experienced a significant decrease (more than 2 degrees celsius) from pre-measurement to handling. For Hens the Comb saw the most significant temperature drop during handling which is consistent with previous research. The Head saw the most significant decrease in temperature during handling for Roosters. Roosters Head Eye and Comb temperatures in post measurement went on to exceed those obtained in pre measurement while for Female subjects Head, Eye and Comb temperatures never returned to pre-measurement levels during the 20 minute post measurement. Infrared thermography proved a useful and accurate measure of Chooks surface area temperature. A surface area temperature decrease of more than 2 degrees celsius was observed in all subjects. All subjects met the requirements for stress-induced hyperthermia after handling. Stress-induced hyperthermia had a significant and lengthy impact on Chooks, in particular Hens