EFFECT OF ANABAENA AZOLLAE ON FISH QUALITY, NUTRITIVE COMPONENTS AND ITS ANTIBACTERIAL ACTION ON AEROMONAS HYDROPHILA.

摘要

A total of 60 of Tilapia nilotica fish brought frotn El-khashea farm in kafi- El-sheikh govemorate in plastic cage to Animal Health Institute. Then fish were divided into 3 groups in 3 glass aquarium each one contain 20 fish (Nile tilapia). The fish were fed on the experimental diets during 6 weeks of the experimental period. Fish were fed during the acclimation period on an artificial basal ration at a rate of 3% of the body weight 1 meal daily. Fish in the first group fed on non supplemented control diet while, fish in the second and third groups (Ai, A2) fed on diets supplemented with 10 & 15% Anabaena azollae respectively. The control, first and second experimental groups (Ai, A2) was infected with A.hydrophila by using concentrate lxlO‘’cfij/gm. This experiment was designed to study the effect of Anabaena azollae on fish quality, chemical composition of fish including moisture, crude protein, carbohydrates, fat and ash as well as its antibacterial action on A.hydrophila. In control group thebacterial coimt of A.hydrophila was ranged Irom 2x10~5 to 4x10~5 with mean value 3xl0~5±lxl0~4 cfli/gm, In group (Ai) the count of A.hydrophila was ranged fi-om 1 x 10~4 to 2x 10~5 with mean value 2x 10~4±1 x 10~4cfu/gm. In group (A2) the count of A.hydrophila was ranged Irom 1x10~2 to 1x10 with mean value 2xl0~3±lxl0~3 cfii/gm. In vitro sensitivity test showed that the anabaena has antibacterial effect on A.hydrophila by 2 concentrations 10% and 15% with inhibition zone 0.8-0.9 mm respectively. Chemical composition of fish in the control grou^) showed mean values for carbohydrates, protein, fat, ash and moisture as 0.9+0.07, 19.9±0.3, 2.9±0.14, 1.8±0.09 and 73.25±0.2% respectively. The mean values of carbohydrates, protein, fat, ash and moisture in first group (A_1) were 0.76±0.09, 21.3+0.3, 2.68±0.1, 1.58±0.16 and 72.9±0.3% respectively. Chetfiical composition percentage (%) of fish in the second group (A_2) were 0.73+0.07, 21.5+0.3, 2.4+0.19, 1.63+0.1 and 72.48±0.31 for carbohydrates,protein, fat, ash and moisture respectively. So, the mean of A.hydrophlila count decrease gradually from control group to group A_1 with Anabeana 10% to group Aj with Anabeana 15%. In addition the mean of moisture carbohydrate % and fat % decreases gradually fi-om control group to group A_1 to group A_2. While the mean of protein % increase gradually from control group to group Ai to group A_2. In addition the mean of ash % decrease from control group to group Ai to group A_2.