Effects of Dietary Marshmallow (Althaea Officinalis L.) Extract on Growth Performance and Body Composition of Common Carp (Cyprinus Carpio)

Objective: This study was conducted to evaluate the effects of different proportions of marshmallow extract (Althaea officinalis L.) on growth performance and carcass composition of common carp (Cyprinus carpio). Methods: Common carp with an average weight of 37.65 ± 4.40 g were fed for two months with a diet supplemented with marshmallow (A. officinalis) extract 0.25%, 0.50 and 1%, and with normal diet as controls. The hepatosomatic index (HSI) and viscerosomatic index (VSI) were assessed on days 30 and 60. The growth performance including weight gain, specific growth rate (SGR), feed conversion ratio (FCR), and condition factor (CF) were measured on days 15, 30, 45 and 60.  Results: Results of the present study showed that specimens fed a diet supplemented with marshmallow extract (0.25%) exhibited dramatically increased growth performance, which was the highest amongst all treatments (P< 0.05). The addition of marshmallow extract did not have any effects on hepato-somatic index (HSI), intestine-somatic index (ISI) and condition factor when compared to the control diet. However, administering high levels of marshmallow extract had adverse effects on growth performance of specimens. Our results showed slight changes in body composition of fish fed a diet supplemented with marshmallow extract compared with controls. It can be concluded that marshmallow extract 0.25% can act as a growth stimulator. On the other hand, high levels of marshmallow may have anti-nutritional factors that decrease the utilization of the given feed.