EFFECT OF AMMONIA ON NILE TILAPIA (O. niloticus) PERFORMANCE AND SOME HEMATOLOGICAِL AND HISTOLOGICAL MEASURES

Nile tilapia (O. niloticus) fingerlings averaging 19.0 ± 1.0 g in weight where reared at four different concentrations of UIA-N (0.01, 0.05, 0.1 and 0.15 mg/l) besides the control using 15 glass aquaria (40 ×70 ×60 cm). Tilapia were stocked for 75 days and fed with diet containing 26.58 % protein. The physico-chemical analysis of water in aquaria were recorded. Water was changed twice daily with 100 % of water size. Different growth measurements of tilapia were recorded every 15 days interval, blood parameter and histo-pathological changes in kidney, liver and gills were also recorded. The results showed that growth performance was significantly (P ≤ 0.05) decreased with increasing concentration of UIA-N. The feed conversion ratio (FCR) increased with increasing concentrations of UIA-N, the differences were significant (P ≤ 0.05) among the high concentrations. Histopathological changes showed different signs in liver, gill and kidney among the four treatments. Increasing UIA-N concentrations resulted in decreasing of hematocrit and hemoglobin parameters, while differences were not significant (P≥ 0.05) from control in UIA-N concentration (0.01mg/l). Also, results showed that the 48 hr-LC50 for tilapia fingerlings was 7.1 mg/l NH3-N