الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 108 |  |  |
| | | from | 108 | | |
Abstract
The Present study was carried out at a private farm in Eighty-Three area located in Kafr El-Sheikh governorate, Egypt, during summer season 2020. Four experimental diets were prepared by mixing the fish meal, soybean meal, corn meal, wheat bran, gluten, rice bran, wheat flour, vitamin, and mineral mixture, dicalcium phosphate, and vitamin C. Then oregano essential oil was mixed with the basal diet at 0, 0.25, 0.5, and 1 g/kg on growth performance parameters, feed utilization, body composition, histology and chemical analysis of Nile tilapia (Oreochromis niloticus) fingerlings. In Eighty-Three area located in Kafrelsheikh, Egypt, Fish were kept in two 500 L tanks provided with continuous aeration for adaptation. For two weeks, fish fed the control diet twice daily (08:00 and 15:00), and the water was replaced with free chlorine water. Afterward, one hundred eighty fish with similar average initial weight (26.15 ± 0.15 g) were stocked in twelve concrete tanks (1 × 1 × 0.7 m) (fifteen fish per tank). Each tank was supplied with inlet and outlet, in a flow through system. The trial was conducted during the summer season in outdoor concrete tanks, and the water temperature was recorded 31–33 ◦C. For eight weeks, triplicate aquaria were fed the respective test diets at 3% of the body weight twice daily (08:00 and 15:00). The water quality in each pond was checked regularly during the trial and recorded 32 ± 1.2 ◦C, 7.21 ± 0.32, 6.41 ± 0.3 mg/L, and 0.21 ± 0.02 mg/L for the water temperature, pH, dissolved oxygen, and total ammonia, respectively.