Preparation Of Selenium Enriched Yeast And Applicationin In Aquaculture Of Sea Cucumber Apostichopus Japonicas

As a kind of organic selenium additive, selenium enriched yeast is a safe and non-toxic diet additive to animals. It is reported that selenium enriched yeast could improve the physiological function, growth performance and immunity of animals. Vitamin E(VE) as an important immune enhancer plays an important role in maintaining the normal metabolism and physiological function of animals. Therefore, as feed additives, selenium enriched yeast and VE have a broad prospects for the healthy farming of sea cucumbers. At the same time, the application of selenium enriched yeast and vitamin E also could provide a theoretical basis for edible safety of the aquatic products especially the sea cucumber products.A feeding experiment of 60 days was conducted to determine the influences of selenium enriched yeast with different levels of 0, 106, 107, 108 CFU/g diet on growth, digestion and immunity in sea cucumber Apostichopus japonicas. The results showed that, sea cucumbers fed with selenium enriched yeast at doses of 107 and 108 CFU/g diet had significant effects on the specific growth rates and the acticies of protease, amylase, cellulase and alginase(p<0.05). The activies of SOD, LSZ and PO were significantly improved for the sea cucumbers fed with selenium enriched yeast at the dose of 107 CFU/g diet(p<0.05); The activies of SOD, T-NOS, AKP, LSZ and PO were significantly improved for the sea cucumbers fed with selenium enriched yeast at dose of 108 CFU/g diet(p<0.05); the best disease resistances were found for the sea cucumbers fed with selenium enriched yeast at the doses of 107 and 108 CFU/g diet(p<0.05). Therefore, the suitable additional concentration of selenium enriched yeast for sea cucumbers was 108 CFU/g diet.Effects of dietay addition of selenium enriched yeast(108 CFU/g), VE(300 mg/kg), the combination of selenium enriched yeast(108 CFU/g) and VE(300 mg/kg) on growth, digestion, immunity and antioxidant capacity of sea cucumbers were studied. The results showed that sea cucumbers fed with selenium enriched yeast and the combination of selenium enriched yeast and VE could significantly improve the SGR and the contents of selenium and VE of body wall(p<0.05). It is shown that sea cucumbers fed with VE could significantly improve the contents of VE in the body wall(p<0.05). It is shown that the activities of amylase and alginase were significantly improved for the sea cucumbers fed with selenium enriched yeast(p<0.05); and the sea cucumbers fed with VE could significantly improve alginase activities(p<0.05); dietary addition of the combination of selenium enriched yeast and VE could significantly improve the activities of protease, amylase, cellulase and alginase(p<0.05). The results of non-specific immune and antioxidant capacity of sea cucumber Apostichopus japonicas showed that sea cucumbers fed with selenium enriched yeast could significantly enhance the levels of LSZ, PO, T-NOS, ACP, SOD, GSH Px and T-AOC, meanwhile, reduce the content of MDA(p<0.05). The sea cucumbers fed with VE could significantly reduce the MDA content of animals(p<0.05); and dietary addition of the combination of selenium enriched yeast and VE could significantly enhance the levels of LSZ, NOS, SOD, GSH PX and T-AOC of Apostichopus japonicus(p<0.05). In summary, the best dietary addition level for selenium enriched yeast was 108 CFU/g, compared to VE and the combination groups, the enhancement in inmmunity for selenium enriched yeast group was the best. And the best digestion enhancement effect for combination group was the best.