Journal Article
Growth and nutritional trials on transgenic Nile tilapia containing an exogenous fish growth hormone gene
M. A. Rahman; A. Ronyai; B. Z. Engidaw; K. Jauncey; G‐L. Hwang; A. Smith; E. Roderick; D. Penman; L. Varadi; N. Maclean
Journal of Fish Biology · Vol. 59, Issue 1 · pp. 62-78 · 2001
Abstract
In a long‐term growth trial, transgenic tilapia Oreochromis niloticus L. showed a 2·5‐fold increase in growth compared with non‐transgenic siblings. At 7 months, mean mass of transgenic tilapia was 653 g compared with 260 g for non‐transgenic siblings. A significant increase ( P >0·01) in head: total length ratio, viscera‐somatic index and hepato‐somatic index was observed in transgenic fish. Female gonado‐somatic index ( I G) was found to be lower in transgenics than non‐transgenic siblings in both mixed and separate culture conditions. Transgenic male I G values were found to be higher in mixed culture and lower in separate culture than that of their non‐transgenic siblings. Food conversion efficiency was more than 20% greater in the transgenic fish. In a second shorter‐term growth performance trial, the transgenic fish grew to about four times the size of their non‐transgenic siblings. A digestibility trial suggested that transgenic tilapia were more efficient utilizers of protein, dry matter and energy. Apparent digestibility of protein and apparent energy digestibility were higher in the transgenic fish.