Investigation of body surface temperature measured with infrared imaging and its correlation with feed efficiency in the turkey (Meleagris gallopavo)

As feed intake is an expensive trait to measure in a breeding program, this study investigated whether body surface temperature was correlated with feed efficiency in the turkey. Infrared images were captured on male turkeys in individual feeding cages at approximately 19-weeks of age. Body surface temperature was measured on the eye, head, distal metatarsus, and neck of the birds with temperatures ranging from 34 °C to 40 °C. Body weight, feed intake, and weight gain data were collected and feed efficiency was measured as residual feed intake (RFI) and feed conversion ratio (FCR). Distal metatarsus temperature showed moderate correlations with body weight (0.15), average daily gain (0.26) and feed intake (0.23). Surface temperature of the head, eye, and neck were not as strongly correlated with these production traits. The feed efficiency traits showed low correlations with eye temperature ranging from −0.05 to −0.12 and surface temperatures at the head, distal metatarsus, and neck were not correlated with feed efficiency. Surface temperature traits explained only a small proportion of variation in feed intake. While the collection of infrared images was efficient and required minimal contact with the caged birds, the low correlations indicate that the technology, as used in this study, has limited advantages for increasing the accuracy of selection for feed efficiency.

► Traits correlated with feed intake or efficiency are important to investigate as the traits are expensive to record.
► Infrared thermography could be used to record body surface temperature on turkeys at the head, neck, eye, and distal metatarsus.
► Average surface temperatures was warmest at the neck (38.2 °C) and coolest at the eye (34.3 °C).
► Body surface temperature at these sites was normally distributed in the turkey.
► Surface temperature traits were lowly correlated with feed efficiency.