Effect of different levels of zinc on growth performance and gonadosomatic index of nile Tilapia (Oreochromis Niloticus) females [electronic resource].

Includes reference.

The present experiment was conducted at the Central Laboratory for Aquaculture research in order to investigate the optimum growth performance, survival rate and gonadosomatic index of (Oreochromis niloticus) females reared in glass aquaria as affected with different levels of zinc. The experimental system consisted of 18 experimental glass aquaria (80x40x50 cm). Each aquarium was stocked with 10 of (O. niloticus) females, which fed diets with different levels of zinc 0.0, 10, 25, 50, 75 and 100 mg / kg diet, respectively. The results indicated that there were significant differences in growth performance among zinc levels feed. The averages of final body weight, weight gain and daily weight gain showed that the highest results were obtained from the level 25 mg Zn / kg diets followed in a decreasing order by 50, 75, 100 and 0.0 mg Zn (the control) levels. The survival rate at 25 mg Zn / kg diets was the highest results than other treatments. The highest value of gonadosomatic index (2.14) was obtained from level of 50 mg Zn / kg diet,; than other treatments. The present results found that the optimal growth performance, survival rate and. gonadosomatic index of (Oreochromis niloticus) females fingerlings was obtained from level of 25 mg Zn / kg diets.

Summary in arabic.

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