BACKGROUND: Enhancement of the immune system seems to be the most promising method of preventing fish diseases and increasing growth rate. Objectives: The purpose of the present study was to investigate the influence of dietary administration of Zataria multiflora Boiss and Menthapulegium L extracts on phagocytosis, lysozyme, respiratory burst and total white and red blood cells (WBC/RBC) of rainbow trout (Oncorhynchus mykiss). Methods: Two hundred and ten fish (100±10 g) were used in a completely randomized design with 7 treatment and 3 replicates in a 2 weeks period (from 0 to 14 d). The basal diet supplemented with 0 (control), 20, 50 and 100 mg/kg food Z. multiflora and M.pulegium extracts. At the end of the experiment (after 14 days), samples from kidney and blood of the fish were collected in order to determine WBC/RBC (by neubauer chamber), serum lysozyme activity (by turbid metric assay, phagocytosic (by number of yeast cells phagocytosed method) and respiratory burst activities (by reduction of nitroblue tetrazolium method) of head kidney tissue. Results: The results indicated that the highest ratio of phagocytosis and respiratory burst activity was observed in 50 mg/kg extract concentration of Z. multiflora (p<0.05). The highest WBC lysozyme activities were seen   in 100 mg/ kg extract concentration of Z. multiflora. No significant difference was shown between RBC in treatment groups and control group (p>0.05). The highest ratio of phagocytosis activity was observed in 100 mg/kg extract concentration of M. pulegium (p<0.05). No significant difference was observed between WBC /RBC, lysozyme, respiratory burst means in treatment groups and control group (p>0.05). Conclusions: It can be concluded that 50 and 100 mg/ kg of the methanol Z. multiflora and 100 mg/ kg M. pulegium have positive effects on stimulating of innate immune system in O.mykiss, but the influence of Z. multiflora extract with100 mg/ kg  concentration is  better than  M. pulegium extract.

BACKGROUND: Probiotics, in form of microbial supplements, are known to be a suitable alternative for antibiotics and can affect the health indicators of host. Objectives: The present study was conducted to assess the combined effects of dietary autochthonous Saccharomyces cerevisiae and Aspergillus niger on haematological and serumbiochemicalparameters of beluga sturgeon (Huso huso) juveniles. Methods: This study was based on a completely randomized design with 4 treatments and 3 replicates on beluga juveniles with average weight of (mean ±SE) 31.8±2.81g. Beluga Juveniles were divided randomly into 12 fiber glassy tanks with density of 30 fish per tank and were fed with diet contain dietary probiotic with density of 2×106 (Cells/g) for the first treatment, 4×106 (Cells/g) for the second treatment, 6×106 (Cells/g) for the third treatment and basal diet without probiotic for the control group for 8 weeks. Results: Diet supplementing with concentration of 6×106 (Cells/g), significantly improved serum biochemical parameters (p<0.05), however hematological parameters were affected by supplemented diet with probiotics that showed no significant difference in comparison with the control group (p>0.05). Also results indicate that growth factors were improved in experimental treatments in comparison with the control group. Conclusions: The results showed that the use of combination of these species with studied concentrations can improve the performance of some biochemical parameters such metabolites factors, immune, enzymes and serum electrolytes of belugajuveniles. It is recommended that the concentration of A. niger and S. cerevisiae, used for third treatment be used as an immune stimulator for beluga juveniles.

Diminazene aceturate is one of a limited number of drugs currently being used in animals to treat the tsetse fly-transmitted protozoal disease, African trypanosomiasis. Efficacy of the drug at the recommended single IM administered doses of 3.5 and 7.0 mg/kg of body weight is widely acknowledged. However, resistance to the drug at these dosages has been reported. Although the mechanisms of resistance to diminazene are poorly understood, field and experimental data indicate that it may develop naturally through administration of subcurative doses, or as a result of cross-resistance. Evidence from other experimental studies indicates that there are additional mechanisms by which trypanosomes may develop resistance to diminazene aceturate. For instance, some populations ot Trypanosoma brucei and T. vivax are refractory to treatment because of their ability to invade the CNS, a site that is believed to be poorly accessible to diminazene. Furthermore, in recent studies carried out in goats, it has been documented that the ability of T. Congolense IL 3274 to survive treatment with diminazene depends on the stage of infection when treatment is administered; populations of the parasite reappeared in animals that were treated on day 19 after tsetse fly challenge, whereas all goats were cured when treated on day 1 of infection. Because trypanosomes are confined to the skin on day 1 after infection, but thereafter invade the blood circulation, it is possible that the efficacy of the treatment on day 1 is attributable to exposure of the small number of parasites, relative to later stages of infection, to higher concentrations of drug than those attained in blood. The objective of the study reported here was to determine whether diminazene's pharmacokinetics differ between plasma and lymph draining the skin of goats and therefore account for the variation in therapeutic activity of the drug at different stages of a tsetse fly-transmitted infection. Peripheral lymph was used for this work because it appears to be identical in composition to tissue interstitial fluid, into which trypanosomes are inoculated by infected tsetse flies when feeding.