Breed Effects on Growth Performance, Blood Parameters and the Levels of Metabolic Hormones in Rabbits Under Heat Stress in Egypt

Document Type : Original Article


1 Animal Wealth Development Department, Faculty of Veterinary Medicine, Zagazig University, 44511, Egypt

2 Department of Husbandry and Animal Wealth Development, Faculty of Veterinary Medicine, University of Sadat City, Menofia, Egypt.


This study was constructed to investigate the differences between three breeds of rabbits [New Zealand White (NZW), Rex and Egyptian Gabali (Al-Gabali)] under heat stress regarding growth traits, hematological, biochemical and immunological parameters, oxidative stress biomarkers as well as metabolic hormones. Thirty rabbits of each breed (4 weeks of age) were subjected to heat stress (32 ± 1°C, 70-80% relative humidity) in the summer season at the period from mid-July to the end of August 2019. Blood samples were collected at 10th week of age. The results revealed that body weights of NZW and Rex were higher by 205 and 145 g, respectively than those of Al-Gabali as well as average daily gains of NZW and Rex were higher by 4.42 and 3.40 g/day, respectively  compared with Al-Gabali (P <0.05). Average daily feed intake of Rex was lower by 7.65 g/day than those of NZW and 2.89 g/day compared with Al-Gabali (P <0.05) and they had the lowest feed to gain ratios (3.58±0.097). Aspartate aminotransferase, urea and creatinine were significantly lowered in the plasma of Al-Gabali compared with NZW and Rex whereas, Al-Gabali recorded higher total proteins (5.90±0.048 g/dL), total globulins (2.50±0.054 g/dL), antibody titer against sheep red blood cells (6.38±0.111) and superoxide dismutase (7.42±0.163 IU/L) than NZW (5.66±0.069 g/dL, 2.21±0.084 g/dL, 4.90±0.068 and 6.80±0.053 IU/L, respectively) and Rex (5.74±0.072 g/dL 2.25±0.095 g/dL, 4.25±0.095 and 6.88±0.050 IU/L, respectively). Al-Gabali bunnies had higher immunoglobulin G, immunoglobulin A, catalase and glutathione peroxidase than NZW and Rex. However, Al-Gabali recorded the lowest insulin (15.64±0.20 ng/mL), growth hormone (45.80±0.48 ng/mL) and triiodothyronine (136.20±2.15 ng/mL). In conclusion, Al-Gabali rabbits were better adapted to heat stress compared with NZW and Rex, which was reflected in the improvement of health, immunity and oxidative stress indicators as well as lower plasma metabolic hormones, but they didn't have the genetic potential for growth traits.


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