and its effect on chick quality

Monitoring the hatch process demands continuous assessment of the number of hatched chicks, which is usually a disruptive event as it requires the incubator door to be opened. Therefore, a real-time monitor for the hatching time of individual chicks is of interest to both researchers and industry. An alternative non-invasive method which involves measuring the eggshell temperature using small, accurate temperature sensors is presented. Continuous recordings of eggshell temperature (Tegg) of the focal eggs were analysed and the temperature profiles for plotted Tegg showed a temperature drop of around 2-6 °C when the chick hatched. It was therefore possible to identify the hatching time for individual eggs in real time during incubation based on this registered temperature drop. Furthermore, linear regression analysis showed a positive correlation between hatching time (r=0.32; P=0.001) and chick weight at take-off which indicated that early hatched chicks started to lose weight during the holding period.