THERMOREGULATORY ASSESSMENT, GROWTH RESPONSE AND INTERNAL ORGANS WEIGHT OF HEAT-STRESSED RABBIT BUCKS FED DIET SUPPLEMENTED WITH BLACK SEED (Nigella sativa)

This experiment was carried out to evaluate the thermoregulatory indices, growth response and internal organ weights of heat-stressed (HS) rabbit bucks fed Nigella sativa (NS) supplemented diet. Thirty growing rabbit bucks were assigned to five treatments of six rabbits each in a Completely Randomized Design. The five treatments were designated as T1-Positive control (PC), T2-Heat stress (HS), T3- rabbits fed NS before (HSbNS), T4-during (HSdNS) and T5- after (HSaNS) HS inducement. Parameters evaluated are respiratory rate (RR/min), pulse rate (HR/min), rectal temperature (RT) and ear temperature (ER) which lasted 14 weeks. Average daily weight gain (ADWG) and feed conversion ratio (FCR) were also determined. At the 14th week, rabbits were humanely sacrificed and the internal organs (Heart, Lungs, Liver and Kidney) were weighed. The RR, HR, RT and ER were all (p<0.05) elevated in T2 compared to the rest of the treatments. The least (p<0.05) ADWG was recorded at T2. Treatments T3, T4 and T5 recorded (P<0.05) increased ADWG. However, T2 had (P<0.05) highest FCR while T3, T4 and T5 had (P<0.05) comparatively least FCR. The relative internal organ weights increased (p<0.05) at T3, T4 and T5. Diet supplemented with NS showed effectiveness on the thermoregulatory activities of HS rabbit bucks in terms of RR, HR, RT and ER. The NS supplementation in heat-stressed rabbit’s bucks’ diet enhanced ADWG, lowered FCR and increased relative organs weight of the rabbits. Feeding diet supplemented with NS to HS rabbit bucks will ameliorate the adverse effects of heat stress on the physiological wellbeing.