IMPACT OF DIETARY SUPPLEMENTATION WITH NANO AND ORGANIC SELENUIM WITHOUT OR WITH VITAMIN E ON GROWTH PERFORMANCE AND SELENIUM METABOLISM IN GROWING RABBITS

The objective of the present study was to examine the effects of dietary supplementation with two sources of selenium (Se), organic (Org-Se) and Nano-Se without or with vitamin E (Vit-E) on growth performance and Se metabolism in New Zealand White (NZW) growing rabbits. In a factorial experimental design (2x3), ninety weaned NZW rabbits of 5 weeks old and with average body weight, 579.5 ± 5.53g were used in the study for 56 days. Rabbits were randomly distributed into 6 experimental groups and fed the following six diets : (1) control Basal diet without any supplementation, either Vit. E or Se; (2) Basal diet + 250 mg Vit. E/ kg diet; (3) Basal diet + 0.3 mg Org- Se /kg diet; (4) Basal diet + 0.3 mg Org -Se /kg diet+ 250 mg Vit. E/ kg diet; (5) Basal diet + 0.3 mg Nano-Se  /kg diet; (6) basal diet + 0.3 mg Nano-Se /kg diet + 250 mg Vit. E/ kg diet. Results of the experiment revealed that live body weight (LBW) and total body gain (TBG) were significantly higher (P< 0.05)  and feed conversion ratio (FCR) was the best with rabbits fedbasal diet plus Nano-Secompared to those fed the control diet or rabbits fed  basal diet plus Org-Se.  However,with adding Vit. E to the basal diet, the differences in these traits were not significant among the rabbit groups. Selenium concentrations in kidneys, liver, muscles and blood serum were insignificantly higher in rabbits fed supplemental Nano- Se than in those fed basal diet without any supplementation (control) or those fed supplemental Org-Se. However, Se concentration significantly increased (P< 0.05) in kidneys and liver in rabbit groups fedsupplementalvitamin E and was the highest in rabbitsfed supplemental Nano-Se plusVit. E. Selenium concentration in muscles and blood serum showed statistically similar values among rabbit groups fed diets supplemented with Vit. E. The economic efficiency (%) was statistically the same with rabbits fed either Nano-Se plus Vit. E or control diet plus Vit. E, while, it was the lowest with rabbits fed Org- Se compared to the control and other groups.  Conclusively, based on the results of the present experiment and from the economic point of view and to ameliorate the adverse effects of heat stress on growing rabbits during the hot summer conditions in Egypt, it is advisable to supply the basal rabbit diet with  Se, either as Nano- Se or  Org- Se only without  Vit E diet. There are still future studies to determine the effect of Nano Se on human and animal health.