Thermoregulatory Response of Exotic Rabbit Breeds During Peak Temperature – Humidity Index of Ibadan

Abstract

An experiment was conducted to assess thermoregulatory responses of four exotic breeds of rabbit between February and March (when highest Temperature - humidity index is observed). The breeds included Fauve De Bourgogne (FDB), Chinchilla (CHA), British Spot (BS) and New Zealand White (NZW) rabbits. 10 bucks and 7 Doe per breed housed individually were used for this study. Temperature - humidity index (THI) of the rabbitry microclimate at 08:00h and 14.00h were measured, thermoregulatory indices of rabbit; Respiratory Rate (RR), Heart Rate (HR), Rectal Temperature (RT) and Ear Temperature (ET) were assessed at 08.00 to 10.00h and 16.00h to 18.00h daily for eight weeks. Data were analyzed using ANOVA at α_0.05. The results obtained showed that the average daily THI obtained in February and March was 29.94 and 28.59, respectively. The average daily RR and HR in Chinchilla and British spot rabbits were significantly (p<0.05) higher than in New Zealand white rabbits.  Daily ear and rectal temperatures of British spot and New Zealand white rabbits were statistically similar (p>0.05) and significantly (p<0.05) lower than Chinchilla.  It is evident from this study that, British Spot breed of rabbit had the most effective thermoregulatory activities, while New Zealand white had the least susceptibility to heat stress, during highest THI in Ibadan.