The effect of cherry laurel (Laurocerasus officinalis) leaf extract on the survival, growth ratio and catalase enzyme activity in liver of rainbow trout (Oncorhynchus mykiss) reared in commercial production conditions

In this study, the effects of using cherry laurel (Laurocerasus officinalis) leaf extract, which has known antioxidant feature, in diet in commercial production conditions on the survival rate, growth parameters, biochemical composition and catalase enzyme activity in liver of rainbow trout (Oncorhynchus mykiss) during the summer season causing economic loss since high water temperature were investigated. For this purpose, two studies, one of which was a preliminary study, were conducted. In the preliminary study, the effect of cherry leaf extract supplementation to the diet with different concentrations (0, 1, 2.5, 5, 10 and 15 g extract / kg feed) on the survival rate of rainbow trout at high temperature (21 ° C) in aquarium conditions was examined and the most appropriate concentration was determined as 10 g extract / kg feed. In the other study carried out in a commercial company, the effect of cherry leaf extract supplementation into the diet with a more reasonable concentration (5 g extract / kg feed) because of easily obtainable and manual preparation of the diets on the survival rate, growth parameters, biochemical composition and CAT enzyme activity in the liver of rainbow trout were searched. It was determined that cherry leaf extract supplementation to the diet with this concentration did not have any statistically significant effect on the parameters examined (p> 0.05), except for moisture and crude lipid (p<0.05), on the other hand survival rate in the experimental group was higher than the control group. As a result, it can be said that cherry laurel which is economic and easily obtainable plant has a potential as a new antioxidant substance that increases the survival rate in rainbow trout cultivation by supplementing to the diet during the temperature rise in summer months