Thermophysiological traits in four exotic breeds of rabbit at least temperature-humidity index in humid tropics

Background: We deciphered thermoregulatory activities of exotic breeds of rabbit in the event of least thermal discomfort in Ibadan, Nigeria. This investigation was carried out between July and August during the least temperature-humidity index (THI). Twenty bucks and 14 doe per breed, housed individually and randomly assigned to experimental units in a completely randomized design, were used for assessment of respiratory rate (RR), heart rate (HR), rectal temperature (RT) and ear temperature (ET). Measurements were taken between 07.00 to 09.00 h and 16.00 to 18.00 h of the day, using standard procedures. Result: The result obtained showed that the effect of sex was evident in respiratory and heart rates, with males having higher values in the evening. But the core body temperature was not affected. Although the higher function of thermoregulatory apparatus of Fauve de Bourgogne, Chinchilla and British Spot rabbits were recorded, New Zealand White had lower core body temperature than other breeds. Conclusion: We reported that August was the most thermal comfortable period during the year for rabbit in Nigeria. New Zealand White has a lower core body temperature without a compensatory increase in thermoregulatory activities.