Effects of feed colour on growth and nutrient utilization of Tilapia zillii (Gervais 1852)

A feeding trial was conducted for 75 days to determine the effects of feed colours on nutrient utilization and growth in Tilapia zillii fingerlings. Four different food colourant \{Food Drug and Cosmetic (FD and C) colour red, blue, green and yellow\} was added to a basal diet 350g crude protein and 18.5MJ gross energy/kg diet and fed to T. zillii. There were five diets in all, the control (normal light brown commercial diet) (Diet 1), red-coloured diet (Diet 2), and blue-coloured diet( Diet 3), green-coloured diet(Diet 4) and yellow-coloured diet (Diet 5) and fed to triplicate groups of T. zillii at 4% body weight. Ten (10) T. zillii (14.00:t 0.003g) fingerlings were stocked in each concrete tank making a total of 150 fingerlings. The growth performance of the fish fed the yellow-coloured diet (Diet 5) had the best growth performance and nutrient utilization with Feed conversion ratio (FCR) and Specific growth rate (SGR) of 0.031:t0.80 and 1.17:t0.On respectively, this was followed by fish fed green-coloured diet, followed by fish fed red-coloured diet, followed by the fish fed the control diet (normal light brown commercial diet) and lastly, the fish fed blue-coloured diet had the least growth performance