Effect of different levels of inorganic supplement in hydroponic system on hemato-immunological responses, intestine bacterial flora and morphology of Nile tilapia (Oreochromis niloticus)

The aim of the present study is to investigate the effect of different levels of inorganic supplements in hydroponic system with the re-use of water on some parameters related to Nile tilapia health status. Materials &

To address that, 180 fish weighing 30±3.8 g was divided into 9 experimental units (3 for each treatment). Three different treatments were applied, including 0, 25 and 75% of nutrient requirement for hydroponic system and these levels were added to the diet of fish. Following 70 days of dietary administration, blood samples were withdrawn for caudal vein of 5 fish. Intestine sample was also taken in order to determine the bacterial microflora and histological changes.

Obtained results showed significant changed in hematological and immunological parameters in dietary treatment as compared with control (P<0.05). Total number of bacteria in intestine was significantly (P<0.05) elevated in treatment 3 as compared with other treatments. The applied diets had significant impacts on histological indices, including villi height and diameter, total number of leucocyte and mucus-secreting cells (P<0.05).

Generally, epithelium development of intestine besides the improvement of hematological parameters and stimulation of immunity system could perhaps indicate the better health status of Nile tilapia following dietary manipulation by inorganic supplementation.