Acute stress assessment using infrared thermography in fattening rabbits reacting to handling under winter and summer conditions

Aim of study: This study assesses acute stress by measuring, through infrared thermography in summer and winter, the temperature of the eye, outer ear, inner ear and nose in 40 fattening rabbits before and after handling. Area of study: Seville (Spain). Material and methods: Body thermographic temperatures were recorded during a 38-day fattening period twice weekly and twice a day, before and after the handler held the rabbits in their arms for one minute. Ambient temperature and relative humidity were also recorded, and their influence on body temperatures was assessed. For each anatomical part, the variation of the temperature between the handled and undisturbed rabbit, and the differential temperature between the anatomical part in the undisturbed rabbit and the ambient temperature were calculated. Main results: The variation in temperatures between handled and undisturbed rabbits ranged from 0.25±0.041 ºC for eye to 3.09±0.221 ºC for outer ear in summer and -0.41±0.182 ºC for nose to 2.09±0.178 ºC for outer ear in winter. The day of the fattening period influenced all the temperature traits during summer and winter, except for the inner ear in winter. In summer, unlike winter, the temperature variation at the end of fattening period between handled and undisturbed rabbits was lower than at weaning (-0.04 to 1.94 ºC vs. 0.54 to 5.52 ºC, respectively). The temperatures in undisturbed rabbits were correlated with ambient temperature. Research highlights: Measuring body temperature with infrared thermography is a useful tool to evaluate acute stress in handled rabbits, with the inner ear and eye the most reliable body parts for measuring it.