RESUMO
This study aimed to evaluate the influence of dietary supplementation with curcumin in a native (CUR) or solid nanoparticles (CURNPs) form as natural antioxidants on productive traits and some physiological functions of heat-stressed growing rabbits. Total of 100 weaned APRI line rabbits (5 weeks old) was distributed according to body weight (BW) into five treatments (n = 20). Rabbits in the first treatment were fed a basal diet (BD, control), while those in treatments 2, 3, 4 and 5 were fed BD containing CUR (25 or 50 mg) and CURNPs (2.5 or 5 mg) per kg diet up to 13 week of age. The mean of air temperature and relative humidity during the growing period were 32.77°C and 43.23% respectively. Final BW, daily weight gain, feed conversion ratio and viability were positively affected by treatments compared with the control diet. Also, CUR and CURNPs treatments significantly increased total proteins, immunoglobulins, total antioxidants capacity, superoxide dismutase, glutathione peroxidase and glutathione in blood serum and hepatic tissues and significantly decreased serum total lipids, total cholesterol, triglycerides, low-density lipoproteins, urea, aspartate transaminases and malondialdehyde (MDA) in hepatic tissues. Albumin and high-density lipoproteins were significantly increased, while alanine transaminases and MDA were significantly decreased by both CURNPs levels. The CUR or CURNPs supplementation may enhance productive performance, lipid profile, liver function, immunity and antioxidant activity, with reducing liver lipid peroxidation of heat-stressed growing rabbits. The best results were obtained by adding 2.5 mg CURNPs/kg diet under the experimental condition of this study.
