The effect of oregano (Origanum vulgare) extract on prevention of S. ineae experimental infection in rainbow trout (Oncorhynchus mykiss)

This study was performed in order to determine the effect of Oregano (Origanum vulgare) extract on Streptococcus ineae infection in rainbow trout. 063 rainbow trout weighing 15±1 gr were randomly allocated into three treatment groups with three repetition, including: 1) Control group, 2) Oregano extract treated group (1% of diet), 3) Felorfenicol treated group (10mg/kg fish), all feed one time a day for two weeks. At the end of the second week, 5 fish of each repetition collected and sampled from their blood and tissue of spleen and kidney. After the bleeding, all the samples injected with streptococcus ineae. After two weeks mortality rate calculated and after the bleeding, sampled from the spleen and kidney of the samples. Total cunt analysis conducted on the spleen samples in 4 logarithmic concentrations. in the second phase all the samples primarily injected with S.ineae and then treated with Oregano concentration and Felorfenicol for two weeks. After the two steps of bleeding, in sterile qualifications, the spleen of the fishes sampled for total cunt analysis. Blood cells counting and lisosym activity indicated in all blood samples. The results shown that total mortality in both of the phases of experiment in Oregano extract (OE) treatment was significantly lower comparing to control group (p<0.05). Furthermore the results of blood cells counting shown that WBC and monocyts percents were significantly higher in Oe and Felorfenicol treatment groups (p<0.05). This phenomenon was because of the effects of Oe and Felorfenicol. Nevertheless the lysozym activity degreased comparing to control group (p<0.05). But total count analysis shown that bacterial audience in spleen degreased treating Oe and felorfenicol. It was concluded that supplementation of Oe registered lower mortality and bacterial audience, and better hematological parameters in fishes, compared with control group. Therefore supplementation of Oe in fish diet would be effective in prevention and treatment of S.iniae in rainbow trout

Survey on alimentary tract parasites in cultured fish in Khouzestan province

In this study which was carried out in khoozestan province, 1100 pieces of common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix), Grass carp (Ctenopharyngodon idella) and Big head (Arysthychthys nobilis) from different parts of the province were examined. From each part, 10% of the fish farms were sampled according to the fish density at each farm. parasitic infection of gastrointestinal tract were studied on 600 pieces of silver carp (60% ) , 244 pieces of common carp (25%) , 51 pieces of Big head (5%) . only Grass carp was infested to protozoan and metazoan parasites . thirty percent of examined Grass carp of 2-730 gr weight were infested to Hexamita but infestation was more severe in Grass carp with 20-40 gr weight . macroscopic manifestation included : dysphagia , weakness , circulating movements, paling of gills , stomach inflammation , intestinal inflammation , ascitis and yellowish gut contents . in severe and intestinal necrosis along with hyperemia was apparent . the cestoda , bothriocephalus opsariichthydis ( Rudolphi , 1808 ) with an infestation rate of 35 % were only observed in Grass carp in 2-40 gr . Grass carp that showed severe infestation, intestinal blockade was observed with more than 100 parasites. The length of adult cestoda was 450-530 mm and its width was 5mm. in severe infestations, macroscopic manifestations included: ascitis, abdominal inflammation, swimming on water surface and emaciation. Histologic studies showed necrosis of intestinal wall, hemorrhage and localized necrosis. In fishes with severe infestations, inflammation was observed. Infestation with the nematode, capilaria was observed in 10% of 20-750 gr Grass carp. No macroscopic symptoms were identified in the samples, but microscopic examination showed acute necrosis along with hyperamia and submocusal hemorrhage. Lymphocytes were also observed. Adult nematode had a width of 0.075 and a length of 7.5-8.5 mm