Abd Al-Hakim, N., Hessen, M., Rizkalla, E., Hegazi, A., Tahoun, A., Khalfalla, A. (2013). Comparative study for the production of the male Nile tilapia between inter-specific hybridization and hormonal sex reversal. Egyptian Journal of Aquatic Biology and Fisheries, 17(2), 73-89. doi: 10.21608/ejabf.2013.2169
Nabil Abd Al-Hakim; Mohsen Hessen; Esam Rizkalla; Ahmed Hegazi; Al-Azab Tahoun; Ayman Khalfalla. "Comparative study for the production of the male Nile tilapia between inter-specific hybridization and hormonal sex reversal". Egyptian Journal of Aquatic Biology and Fisheries, 17, 2, 2013, 73-89. doi: 10.21608/ejabf.2013.2169
Abd Al-Hakim, N., Hessen, M., Rizkalla, E., Hegazi, A., Tahoun, A., Khalfalla, A. (2013). 'Comparative study for the production of the male Nile tilapia between inter-specific hybridization and hormonal sex reversal', Egyptian Journal of Aquatic Biology and Fisheries, 17(2), pp. 73-89. doi: 10.21608/ejabf.2013.2169
Abd Al-Hakim, N., Hessen, M., Rizkalla, E., Hegazi, A., Tahoun, A., Khalfalla, A. Comparative study for the production of the male Nile tilapia between inter-specific hybridization and hormonal sex reversal. Egyptian Journal of Aquatic Biology and Fisheries, 2013; 17(2): 73-89. doi: 10.21608/ejabf.2013.2169
Comparative study for the production of the male Nile tilapia between inter-specific hybridization and hormonal sex reversal
3Arab Company for Fisheries, Abbassa, Abu Hammad, Sharkia, Egypt
4Aquaculture Dept., Faculty of Fish Resources, Suez Canal University, Suez, Egypt
5Animal Production Dept., Faculty of Agriculture, Al-Azhar University, Cairo, Egypt
Abstract
Tilapia fry were produced by hybridization of males of blue tilapia (Oreochromis aureus) with females of Nile tilapia (O. niloticus) and by sex reversal using oral administration of 3 doses (60, 80 and 100 mg/kg diet) of the androgen 17 α-methyltestosterone (MT) for 28 days. Fry were fattening in earthen ponds for 210 days. All treatment groups that received androgen MT (T3, T4 and T5) showed sex reversal with a significantly higher males proportion than females as compared to the control (T2) and hybrid (T1) groups. The treatment group that received 60 mg MT (T3) exhibited the best growth performance parameters (average weight gain, average daily gain and specific growth rate) and feed utilization parameters (feed conversion ratio, protein efficiency ratio, protein production value and energy utilization). The highest percentage of body crude protein; ether extract and ash were detected in T3 group. With regard to human food safety, tilapias that treated with MT (T3, T4 and T5) rapidly excrete ingested hormone and MT levels falling to lower concentrations than that in both hybrid (T1) and control (T2) groups.