| The studies were conducted to assess the effects of dietary vitamin A, D, E and selenium on the immune status of abalone (Haliotis discus hannai Ino), and determine the nutritional requirements of the juvenile abalone for selenium. The results were summarized as follows:Disease is the main barrier to the development of aquaculture. These years diseases resulted in massive mortality and reduced product quality for abalone, Haliotis discus hannai Ino. Disease is subject to three effectors: pathogens, host and environments, so it is important to improve the immune system of animals to resist diseases. It has long been recognized that nutrition is a key factor in host defense against pathogens. Deficiency or excess of nutrients can alter immune responses and susceptibility of animals to infection. The research on nutritional immunology in aquatic animals is mainly focus on fish, others on crustacean, and little research had been published to discuss the effect of nutrients on immune system of mollusks. This paper concluded simply the research process on some nutrients (vitamin A, D, E and selenium), and some immune indices (total hemocyte counts, phagocyte activity, antioxidant enzymes, phenoloxidase, lysozyme activity and so on).A study was conducted to investigate the effects of dietary vitamin E and selenium on immune status in the abalone. Eight semipurified diets were formulated to provide graded levels of selenium (0, 0.2, 0.6, 1.5 mg/kg) with either 0 or 50 lU/kg VE. The kelp, Laminaria japonica was used as a control diet. Abalone (initial length: 6-7 cm) were distributed in a re-circulating system using a completely randomized design with 9 treatments and 3 replicates pertreatment (7 abalone / replicate). They were fed the appropriate diets once daily for 120 days, and then cellular and humoral immune indices were assessed, including total hemocyte counts, phagocytosis, phenoloxidase(PO), lysozyme, agglutinin activity and total protein concentration in serum (TPC). As the result, dietary selenium and vitamin E had significant effects on total hemocyte counts in hemolymph of abalone (P<0.05). PI (Phagocytic Index), PR (Phagocytic Ratio) and MY (Mean incorporated number of Yeast) were calculated, and only PR was affected significantly by dietary selenium (PO.05). Abalone fed without selenium or vitamin E showed lowest level on these cellular indices. Dietary selenium and vitamin E separately had significant effects on all humoral immune indices, including PO, lysozyme, and agglutinin activity and serum total protein concentration. However, dietary selenium and vitamin E showed significant interaction only on serum total protein concentration. It seemed to be that dietary vitamin E and selenium could affect immune status of abalone, Haliotis discus hannai Ino. Abalone could maintain good immune status when 50IU/kg VE and 0.2-0.6mg/kg Se were supplemented.A two-factorial experiment was designed to evaluate the effects of dietary selenium and vitamin E on antioxidant enzyme activities of abalone. Eight semipurified diets were formulated to provide graded levels of selenium (0, 0.2, 0.6, 1.5 mg/kg) and vitamin E (0, 50 lU/kg); abalone in control group were fed with kelp. Abalone of similar size (6-7cm) were distributed in a re-circulation system using a completely randomized design with nine treatments and three replicates per treatment. They were fed the appropriate diets for 120 days. Thenthe activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione reductase (GR), glutathion-S-transferase (GST) in abalone serum were assessed. Compared to vitamin E, dietary selenium had more efficient effects on antioxidant enzyme activities of abalone. Dietary selenium had significant effects on all the five antioxidant enzyme activities (P<0.05), but VE significantly influenced the activities of only GPX and GR significantly (P<0.05), and there were interactions between Se and VE on theactivities of CAT, GPX and GR. GPX/SOD, GR/GPX and CAT/SOD ratios were selected as... |
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