Effects of different boiling time of soybean (<i> Glycine max</i> (L) merril) on growth performance of tilapia (<i> Oreochromis niloticus</i>) fingerlings

Abstract

A 56-day feeding trial was conducted with Oreochromis niloticus (Tilapia) fingerlings fed soybean boiled at different periods. The period treatment variations were unboiled soybean as control (T₁); soybean seeds boiled for 20 minutes (T₂); 30 minutes (T₃); 40 minutes (T₄) and for 50 minutes (T₅). The soybean seeds so treated were sun dried, milled and were used to formulate iso-nitrogenous diets (25% crude protein). The trials were conducted in hapas of 1m³ submerged in a pond. The diets were fed at 5% body weight and each hapa was stocked with 20 fingerlings. Evaluation of growth parameters and nutrient utilization of fish fed the experimental diets was based on mean weight gain (MWG); specific growth rate (SGR); protein efficiency ratio (PER); food conversion ratio (FCR) and survival rate. There was significant difference (P<0.05) in MWG; SGR; PER and FCR among the various groups of fish fed the experimental diets. Fish fed diet T₄ had the highest MWG (2.40g); SGR (0.63% day^-1); PER (1.76) and conversely the lowest FCR (0.41). While fish fed diet T₁ had the lowest MWG (0.32g) SGR (0.14% day^-1); PER (0.25) and highest FCR (2.39). Therefore fish fed raw soybean had the lowest growth and least utilized the diet.

Keywords: boiling time, soybean, Oreochromis niloticus

Journal of Aquatic Sciences Vol. 21(1) 2006: 15-18