Prof. Mahmoud Mohamed Hazza :: Publications:

This experiment was conducted to evaluate the use of ethanol-extracted from the medicinal plant, Origanium vulgare as a growth and immunity promoter for Nile tilapia, Oreochromis niloticus (L.) fingerlings. Fish (average 12.27 g) were randomly distributed into four treatments; three replicates each at a rate of 20 f i sh per 100 L aquarium. Fish were fed one of the tested diets containing similar crude protein (30 %) and gross energy (4.40 KCal/g), in addition to 0.0, 0.5, 1.0, or 1.5 % Origanium vulgare extract. Diets were given twice daily at a rate of 3 % of live body weight, for six days a week during 10 weeks. After the feeding t r i a l , fish of each treatment were challenged by pathogenic Pseudomonas aeruginosa and Pseudomonas flourscence, which was given by intraperitoneal (l/P) injection and they were kept under observation for 10 days to follow up any abnormal clinical signs and the daily mortality rate. The growth-promoting influence of Origanium vulgare extract was observed on f i s h . The maximum growth was observed at 0.5 % Origanium vulgare extract as compared to the control. No significant differences in fish survival were reported among the experienced treatments at (P>0.05), f a l l i ng within the range of 93.3 - 100%. The control fish consumed less diet and gave a higher FCR, while fish fed diet containing 0.5 % Origanium vulgare extract demonstrated the highest protein efficiency ratio (PER), apparent protein utilization (APU), and energy utilization (EU). The supplementation of Origanium vulgare extract had no significant (P>0.05) effect on the fish body composition (dry matter, crude protein, fat, and ash), meanwhile, total protein, albumin, and globulin increased significantly (P