Wheat Bran Grown Brewers Yeast (Saccharomyces cerevisioe) as Feed for Clarias gariepinus Fingerlings: Carcass Analysis and Growth Performance

A trial feed was prepared by inoculating and growing brewer’s yeast (Saccharomyces cerevisiae) in wheat bran.  The biomass so produced was dried and used to replace fish meal in the diet of Clarias gariepinus at varying levels (0%, 15%, 30%, 45% and 60%) respectively.  The analysis of the fish carcass revealed that the diet D5 with 60% substitution of fishmeal with brewer’s yeast had the highest protein (50.91) followed by D1 (fishmeal only) 45.51.  In growth performance, the fishmeal diet gave better results in Mean Weight Gain (MWG) – 1.27; and Percentage Weight Gain (PWG) – 27.79.  However, the 60% substituted diet showed superiority in Specific Growth Rate (SGR) 4.00 and Nitrogen Metabolism (Nm) – 44.73.  the results therefore are indicative of the fact that wheat bran grown , Brewers yeast can serve as fishmeal replacers at 60% substitution level without adverse effect but improvement on the fish carcass protein and growth performance. Keywords: Brewers yeast wheat bran feeding trial, Clarias gariepinus, carcass composition, growth

Levels of Bioaccumulation of Some Heavy Metals in Fish (Tilapia zilli) and Their Concentration in Water and Sediment of Owubu Creek, Niger Delta, Nigeria

Abstract Bioaccumu lation of some heavy metals were determined in water, sediment and fish samples fro m owubu creek using atomic absorption spectrometer. The result indicated that the order of b ioaccumulat ion of heavy metals in water were 2.85, 0.35, 0.03 and 0.02 for Cu>Pb>Fe>Mg, with Cu having the highest bioaccumulation. In sediment the order of bioaccumulat ion was Fe>Cu>Pb >Cd with their values of 674, 8.31, 6.22 and 0.01 respectively, with Fe having the h ighest value. The order of bioaccumu lation of metals in fish tissue and digestive systems were Fe>Cu>Pb and Fe>Cu>Pb with their values of 72.17, 4.29, 0.01 and 46.12, 2,55, 0.13 respectively, there was high bioaccu mulation of heavy metal in tissue system than in digestive system. The bioaccu mulation factor in fish tissue were 26.81, 0.10, and 0.01 for Cu, Fe, and Pb, while the bioaccumulat ion factor in the d igestive system were 15.93, 0.06 and 0.02 for Cu, Fe and Pb. The b ioaccumulat ion factor in tissue was higher than in d igestive system, th is suggest that the fish samp les could be used to monitor Cu, Fe, Pb pollution levels in owubu creek