ABSTRACT
Background: It is necessary to potentiate the immune system of fishes against stresses in farms
Objectives: This study was carried out to address the potential effect of Levamisole on immune system of rainbow trout against density stress
Methods: 1500 fish [average weight of 50 g] were divided into 5 test groups, in which each test group was repeated three times with average density of 33 kg/m[3]. They were fed with commercial diet supplemented with Levamisole at concentrations of 0 [control], 100, 250, 500 and 1000 mg / kg for a period of 45 days. The fishes of all groups were then fed with Levamisole free diet and exposed to 2 and 3-fold density stress for the following 15 days. Blood samples were collected on days 0, 15, 30, 45 and 60 to evaluate the serum compliment and lysozyme activity as well as total immunoglobulins
Results: The results showed that all used concentrations of Levamisole just had significant effect on compliment activity after 45 days feeding period [p<0.05]. Higher levels of lysozyme and complement activity as well as total immunoglobulin were observed in 1000 mg/kg Levamisole treated group when exposed to density stresses 2 and 3-fold at the end of trial [day 60] [p<0.05]. The highest overall survival was found in group which was treated with 1000 mg/kg of Levamisole
Conclusions: Our results revealed that using 0/1% Levamisole as an im-munostimulator in commercial diet could potentiate rainbow trout against outbreak of high density stresses and increase its overall survival
Subject(s)
Animals , Stress, Physiological/drug effects , Oncorhynchus mykiss , Immunologic Factors , Immune System/drug effectsABSTRACT
Growth of population and food supply is one of the biggest problems in the world and aquaculture plays an important role in food production and supply for human beings. The aim of this study was to evaluate the effect of commercial probiotic [Bactocell] and prebiotic [Manan] on the growth and immune parameters in rainbow trout. Seven hundred and twenty fish were randomly divided into 6 groups with three replicates. The fish in the first group [control] were fed with commercial pelleted diet. The other five groups were fed with 100 mg of probiotic, 2.5 g [grams] of prebiotic, 5 g of prebiotic, 100 mg of probiotic and 2.5 g of prebiotic, and 100 mg of probiotic and 5 g of prebiotic per kilogram of food for 45 days, respectively. Then, all treatment groups were fed with usual food [without probiotic and prebiotic] for 15 days. Growth parameters were evaluated on days 0 and 60. Blood samples were collected for immunological experiments [level of Lysozyme, total antibody levels of serum, and activity of the complement system] on days 0, 15, 30, 45, and 60. All treatments fed with probiotic and peribiotic showed significant improvements [p<0.05] compared to the control group in terms of growth parameters including weight gain, special growth rate, and food conversion rate. The results of immunology also showed that fish fed with a combination of probiotic and peribiotic had a significant difference with other treatments and the control group [p<0.05]. The use of Bactocell and Manan improved the growth and immune response of rainbow trout
ABSTRACT
A trial was conducted to study the effects of different periods of enrichment with ascorbil pulmitate and starvation in cold condition on ascorbic acid [AA] content in nauplii of Artemia urmiana. Four treatment groups with 4 replicates of freshly hatched nauplii were kept at 28°C in incubators containing enrichment medium for 0, 12, 18 and 24 hrs, respectively. Then all of them starved at 5°C for 0, 12, 18 and 24 hrs. AA content was determined using a reversed-phase high performance liquid chromatography coupled with an electrochemical detector. The results showed that nauplii of A urmiana had high levels of AA in their bodies [1534 +/- 166 ug/g DW]. AA content increased following enrichment and reached to their maximum after 18 hrs [3600 +/- 282] and then reduced by 24 hrs of enrichment [2938 +/- 254]. There was a significant difference in AA levels between non-enriched and enriched groups [P<0.05]. Although AA content enhanced in all groups during starvation periods at 5°C, the increases were not significant. However, significant correlations could be observed between duration of starvation and increasing of AA levels in non-enriched, 12 h and 18 h enriched groups. In conclusion, nauplii of A. urmiana had high levels of AA and enrichment with ascorbil plamitate increased their AA content significantly