Production of all male fingerlings through feeding of androgenic steroid (Mesterolone) in the diet fed as first food to tilapia Oreochromis niloticus

Non-conventional hormone, Androgenic Steroid (mesterolone) was prepared and incorporated (using ethanol) at various concentration of 0mg, 30mg, 40mg, 50mg, 60mg each in 0.2kg of fish meal. The six levels were replicated 3 times in plastic tanks. The fish meal incorporated with hormone (mesterolone) were fed as first food to 7 -day old fry of Oreochromis niloticus for 28 days after which the tilapia fry were fed on ordinary fishmeal for another 8 weeks. At the 9th and 12th weeks and after feeding with the hormone, the number of survivals and the weights gained were recorded! After the 12week, the males and females were separated using hand-magnifying lens. The economic viability of all male production using non-conventional hormone (mesterolone) was calculated. Hormone fed to O. niloticus was found to have no significant effect (P>0. 05) on the survival and the mean weight gain of the O. niloticus. But the hormone fed had great influence on the female: male ratio i.e. treatment difference was highly significant (P