Effects of Roselle (Hibiscus sabdariffa) Seeds as a Substitute for Soya Bean on Growth and Nutrient Utilization of Clarias gariepinus (Burchell, 1822)

Effects of replacing soybean meal (SBM) with Hibiscus sabdariffa (HSSM) seed meal as protein sources in the diet of Clarias gariepinus fingerlings (Burchell, 1822) was investigated. Hibiscus sabdariffa seed was processed by soaking for 24 hours, sprouting for 48 hours and fermenting for 72 hours. The processing methods that gave higher crude protein level, and lower anti-nutritional factors were used for the replacement of soya bean. The result shows that the crude protein values (CP) recorded for raw, soaked, sprouted and fermented Hibiscus sabdariffa were 25.49, 25.19, 24.25 and 25.68%, respectively. In view of this, fermented Hibiscus sabdariffa seed meal (FHSSM) was used. Different replacement levels of the soya bean with fermented Hibiscus sabdariffa seed meal (0 control, 25, 50, 75 and 100 %) were allotted to five groups of C. gariepinus fingerlings (4.0 - 4.4 g) randomly stocked at 10 fish per unit in 1 m x 1 m x 1.2 m hapa installed in a polythene lined pond (7 x 5 x 1.2 m) in completely randomized design with an average rainfall of 550 mm and fed for 150 days. The haematological indices of C. gariepinus fed different replacement levels of soya bean with FHSSM were also studied. The haematological parameters indicate that there was no significant difference (P>0.05) among the treatments in most of the parameters. The ANFs in FHSSM are within the tolerable level by fish. This informed the basis for the selection of FHSSM for the feeding trials. Feeding trials conducted indicates no significant difference (P>0.05) in condition factor, survival and protein efficiency ratio (PER) for the various treatments. Better weight gain, feed conversion ratio (FCR) and specific growth rate (SGR) are recorded in fish fed 25% FHSSM. This implies that 25% of soya bean meal in C. gariepinus could be substituted with fermented Hibiscus sabdariffa seed meal without deleterious effect on growth and utilization performance.