Evaluation of toxicological and nutritional valuation parameters of detoxified defatted dietary castor seeds in fish nutrition

Abstract

Castor seed de-oiled into cake (CSC) was differently processed by boiling, roasting, boiling & roasting, decorticated lyle-treated, boiling & fermenting and fed at 10 % in diets to 180 juvenile Clarias gariepinus (Catfish) in a 4-week feeding trial to assay its nutritional and toxicological impact using performance and some bio-data indices. Treatment methods other than boiling improved performance traits and the other measured bio-data such as specific growth rate (SGR), protein efficiency ratio (PER), net protein utilization (NPU), nitrogen metabolism (NM) (p < 0.05). Some processing method(s) (roasting) gave superior results than the others (p < 0.05) relative to the conventional diet. Boiled dietary CSC however, produced the poorest results compared to the other methods and the control diet (p < 0.05). Roasted CSC in diet gave the best result among the dietary treatments (p < 0.05) hence it was recommended that CSC be processed by roasting before inclusion in diet at 10 % for fish.

Keywords: Castor seed cake, Clarias gariepinus, performance, bio-data indices