Effect of dietary supplementation of selenium and copper nanoparticles on the growth performance and feed utilization of nile tilapia (Oreochromis niloticus)‎ fingerlings

الملخص EN

The present study was conducted to evaluate the effect of dietary supplementation of selenium and copper alone or in combination on growth performance, feed utilization and survival rate of Nile tilapia (O.

niloticus) fingerlings in fresh water for 15 weeks.

Apparent healthy 420 fingerlings (3.0±0.1g /each) were distributed randomly into seven experimental groups each treatment was duplicated (30 fish each) as follow: D1.control diet(32%crude protein); D2.basal diet plus 1 mg Se-NP/kg-1; D3.basal diet plus 0.3 mg NaSe/kg-1 diet; D4.basal diet plus 2 mg Cu-NP/kg-1; D5.basal diet plus 3 mg CuSO4/kg-1 diet; D6.basal diet plus 1 mg Se-NP plus 2 mg Cu-Np/kg-1 diet; D7.basal diet plus 0.3 mg NaSe plus 3 mg CuSO4/kg-1 diet.

Tanks (1m3 /each) were aerated and supplied with underground water sources maintained at a constant temperature 24 °C.

All fish groups were hand-fed three meals per day six days a week at feeding level of 6% of live body weight for the first four weeks, 5% for the second four weeks and 4% until the end of the experimental period.

Fish in each tank were counted and weighed (collectively) biweekly, and the total amount of feed consumed during the study period was determined and calculated accordingly.

The results showed that growth performance, feed utilization parameters, survival rate (SR) and condition factor(CF) for fish fed control diet were significantly(p˂0.05) higher compared to those fed diets supplemented with different forms of selenium and copper.

There were no significant (p˃0.05) differences in growth performance on diets containing copper sulphate and copper nanoparticles respectively.

The effect of mixture sodium selenite and copper sulphate on all previous mentioned parameter was more pronounced than the effect of those fed diets containing mixture selenium nanoparticles and copper nanoparticles.

Survival rate didn’t exhibit any significant (p˃0.05) differences among all studied treatments.

Fish fed on diets supplemented with different forms of selenium and copper exhibited a significant (p˂0.05) effect on all estimated feed and nutrients utilization traits.

Feed intake significantly (p˂0.05) increase with control compared to the other treatments however, the bulk of selenium and copper alone or in combination showed a satisfactory results near to the control Feed conversion ratio (FCR) improved with control compared to the other treatments however, the bulk of selenium and copper alone or in combination showed a satisfactory results as well.

However, protein efficiency ratio (PER) and protein productive value (PPV) increased significantly (p˂0.05) with control and bulk of selenium and copper alone or in combination and did not differ significantly (p˃0.05) with all other treatments.

Therefore, the present results recommend that the basal diet improve growth performance, feed utilization and survival rate of Nile tilapia (Oreochromis niloticus) fingerlings.