ADAPTIVE POTENTIALS OF RABBIT (ORYCTOLAGUS CUNICULUS) GENOTYPES TO HEAT STRESS IN SEMI-ARID, NIGERIA

Abstract

Rabbit production under the tropical condition is afected by environmental stress mainly from the effect of high ambient temperatures and high humidity, low wind speed and solar radiation. This study was conducted to investigate the adaptive potentials of rabbit genotvpes in the semi-arid environment. A total number of forty-eight rabbits from two genetic groups were used. Rectal temperature, respiratory rate, pulse rate and heat stress index were measured in Chinchilla and Dutch rabbitgenotypes during late dry season (LDS) and early rainy season (ERS). GLM procedure in SAS was used to analyze data whereby age, breed, sex and season were factors and heat stress indices were the variables. The results showed that breed of rabbit had a significant effect (p<0.01) on respiratory and pulse rates with Chinchilla 97.78±1.05 breath/minute and 141.66±1.46 breathminute respectively while Dutch 92.41±1.08 breath/minute and 134.66±12.68 breath/minute respectively. Breed had noeffect (p>0.01) on rectal temperature and heat stress index. The respiratory rate was significantly higher among female rabbits compared to their male counterpart (96.59±1.65breath/minute vs 93.59±1.08 breath/minute). Age has also significant (p<0.01) effect on the rectal temperature, pulse rate and respiratory rate. Eight weeks old rabbits had higher means values. The heat stress index obtained during the early rainy season was higher (p<0.01) than that obtained during the late dry season (2.20=0.02 vs 1.99±0.01). At the end of the study, Chinchilla rabbits were found to be more prone to heat stress than Dutch rabbits.