Effect of Zataria multiflora essential oils on rainbow trout (Oncorhynchus mykis) complement component activity and lysozyme

Influence of dietary administration of Zataria multiflora Bioss was evaluated on complement component activity and lysozyme of rainbow trout (Oncorhynchus mykiss) to determine stimulatory effect of essential oils. Fish weighting 100±10 g were fed with different doses of 10, 20 and 40 ml/kg food for a period of 10 days. Alternative Complement Activity (CH50%) and serum lysozyme activity were measured on days 1, 8, 15 and 29 after the essential oils administration. The obtained results showed that for first and eighth days of sampling, the complement component mean in treatment groups were significant higher than control group, while negligible difference is shown between treatment groups. For fifteenth and twenty ninth days of sampling, no significant difference was seen in the complement component mean among all examined groups. Also, the results of experiment show that for all of days of sampling, essential oils of Zataria multiflora Bioss have no effect on serum lysozyme activity.