Effect of garlic and yeast in the culture of Nile tilapia (Oreochromis niloticus) [electronic resource].

Includes reference.

Garlic and yeast were evaluated experimentally through using 1200 Nile tilapia (Oreochromis niloticus) fingerling that distributed into 3 equal groups (each of four replicates). Fish of the first group served as a control and received a balance diet. The second and third groups fed on basal diet supplemented with garlic (2%) and yeast (0.02%); respectively for 1 and 2 months. The survival and growth performances were evaluated. Blood samples were collected from the experimented tilapia, one and two months from the onset of the experiment, to measure the haematocrite values (HCV), Nitroblue tetrazolium (NBT), nuetrophil adherence and lysozyme activity. The protective effect of these compounds on fish was evaluated via challenge infection using pathogenic A. hydrophila. The body weight gain, daily body gain, specific growth rates and survival rate were significantly higher in all treated groups when compared with the control group at one and two months of feeding experiment when compared with the controls. The two supplemented groups showed non-significant increase values of hematocrite and nitroblue tetrazolium and significantly increased Neutrophil adherence and lysozymes at one and two months of exposures when compared with the controls but no significant differences were noticed between the two treated periods. The challenge infection showed an improved relative level of protection (RLP) in the 2 supplemented groups when compared with the control . It could be concluded that the supplementation of either garlic or yeast for one month is more potential, less expensive and promising for the production of Oreochromis niloticus in aquaculture.

Summary in Arabic.

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