Short- and long-term effects of a dietary yeast beta-glucan (Macrogard) and alginic acid (Ergosan) preparation on immune response in sea bass (Dicentrarchus labrax).
ABSTRACT The present study investigated the immunomodulatory activity of Ergosan, an algal extract containing alginic acid, and Macrogard, a yeast extract containing beta-glucans, on innate and specific immunity in sea bass (Dicentrarchus labrax). Four cycles of experimental feeding using normal fish feed formulation (control group) supplemented with Ergosan (0.5%) or Macrogard (0.1%) were performed at 60-day intervals (15 days of treatment+45 days of suspension). Serum complement, lysozyme, total proteins and heat shock protein (HSP) concentrations were measured at 15, 30 and 45 days from the end of the first 15-day feeding cycle (short term) and 45 days after the end of each feeding cycle over a 35-week period (long term). The percentage of B- and T-lymphocytes in peripheral blood leucocytes and gut were measured over long-term trial. Significant elevation (P < 0.05) in serum complement activity occurred in sea bass fed with alginic acid and glucans, at 15 days from the end of first cycle of treatment. Significant elevation (P < 0.05) in serum lysozyme, gill and liver HSP concentration were observed in the same experimental groups at 30 days from the end of treatment, whereas a significant increase (P < 0.05) of complement activity was only observed in fish that received an Ergosan diet. At 45 days from the end of treatment, complement, lysozyme and HSP concentration did not differ among groups. Over the long-term period, no significant differences were observed in innate and specific immune parameters, survival, growth performances and conversion index in treated and control fish. A dramatic decrease of both innate and acquired immune parameters was observed during the winter season in all groups, followed by a partial recovery when water temperature increased. Reduction in complement and lysozyme activities was significatively correlated (p < 0.01) to water temperature variation. The results suggested the potential of alginic acid and beta-glucans to activate some innate immune responses in sea bass, and particularly under conditions of immunodepression related to environmental stress.
- SourceAvailable from: Sunit kumar mukhopadhayay
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ABSTRACT: Aquaculture is gaining momentum in several parts of the world in recent years. Intensification has become a common practice in both finfish and shellfish culture to optimize the returns. High stocking densities, artificial feeding and fertilization have become common husbandry practices in both carp and shrimp culture systems. Due to intensification of culture practices, diseases of microbial etiology of economical significance has surfaced in rearing and grow out ponds and are major threat to the sustainability of the aquaculture industry. Synthetic chemicals and antibiotics have been used to prevent or treat fish and shrimp and have achieved at least partial success. Vaccination against specific pathogens has been developed recently with some success depending on the particular disease.An alternative approach has been the application of various compounds to boost or stimulate the innate immune system of farmed fish and shrimp. These compounds, termed immunostimulants is considered an attractive and promising agent for the prevention of diseases in fish and shellfish. In recent years, the established beneficial effects of immunostimulants in many livings systems promote their application for disease management in aquaculture practices.Journal of Marine Science Research and Development. 10/2013; 3(2013).
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ABSTRACT: The study was performed for a period of 60 days to evaluate the effect of dietary carrageenan on growth, haematology, biochemical and innate immunity in rohu Labeo rohita. A basal diet supplemented with iota (І)-Carrageenan at 5, 10 and 20 g kg -1 was fed to three different groups of fish for 60 days and the fishes were examined after 15, 30, 45 and 60 days of experiment. The growth (absolute growth, specific growth rate and percentage weight gain), haematological (total erythrocyte count, total leucocyte count, thrombocyte count and haemoglobin value), biochemical (total serum protein, albumin, globulin and albumin-globulin ratio) and innate immune parameters (NBT and myeloperoxidase activity) were monitored at fortnight interval to assess the effect of I-Carrageenan based diet in L. rohita. All the studied growth, haematological, biochemical and innate immune parameters increased significantly (P<0.05) in carrageenan-fed groups in comparison to control. However, the group which was fed diet containing 10 g kg −1 I-Carrageenan showed the highest value of growth, haematological, biochemical and innate immune parameters on 60 th day in comparison to other groups. The study suggests that I-carrageenan at 10 g kg -1 diet enhances the innate immunity and also the overall health status in L. rohita.The Israeli journal of aquaculture = Bamidgeh 04/2013; · 0.43 Impact Factor