Impact of diurnal temperature - humidity index and sex on the physiological traits of weaner rabbits raised in the derived Savannah.

Abstract

A study was carried out to determine the effect of diurnal temperature - humidity index (THI) and sex on the physiological parameters of weaner rabbits raised in the derived Savannah zone of Nigeria. Twenty female and thirteen male rabbits with were studied in the experiment. Air Temperature (AT) and Relative- Humidity (RH) were monitored with a thermohygrometer at two days interval for 7 weeks while THI was estimated from the recorded AT and RH. Physiological indices of the animals (Respiratory Rate (RR), Skin Temperature (ST), Ear Core Temperature (ECT) and Rectal Temperature (RT) were simultaneously monitored with AT and RH over the same duration. AT (28.19 - 33.29°C) and THI (25.34 - 28.93) contrary to RH (29.95 - 25.49%) were significantly higher (p<0.05) in the afternoon compared to the morning though all the three differed significantly (p<0.05) across the weeks. Similarly, RR, ST, ET and RT were higher in the afternoon and varied significantly (p<0.05) among the weeks. Sex had no effect (p>0.05) on the physiological response of the rabbits regardless of the period of the day. The study concluded that THI was higher in the afternoon and emphasis should be placed on the period of the day rather than sex in mitigation of heat stress in rabbits raised in the derived Savannah.