ABSTRACT
Soybean is an example of feedstuff, commonly used as a protein source in fish diets. There is therefore a necessity for research into non-conventional protein ingredients that can replace soybean without compromising fish growth and health. Therefore, this study examined the substitution of Soya bean meal with Lima beans meal (LBM) in practical diets for Clariid Hybrid catfish (Heteroclarias).
Six iso-nitrogenous and iso-caloric diets with a crude protein level of 40% and energy level of 15% were formulated. Treatment 1 (control), 2, 3, 4, 5, 6 had soybean meal protein substituted with P.lunatus seed meal at 0%, 20%, 40%, 60%, 80% and 100% respectively. They were fed to three replicate of Heteroclarias daily for a period of 84days.
The result obtained from the study showed that the highest weight gain was recorded in treatment 4 (2.28g) that was fed with diet containing 60% Lima beans meal, this was not significantly different (P >0.05) from treatment 3 (2.20g) while Treatment 6 had the lowest weight gain value of 1.58g. Generally, weight gain increased with increasing rate of substitution up to 60% substitution rate (Treatment 4) after which the weight dropped with increase in substitution. There was no significant difference (P>0.05) among the six treatments in terms of feed intake. However, Treatment 6 had the highest feed intake of 4.15g, this was followed by treatment 5 with a feed intake value of 3.82g while the lowest value of feed intake (3.48g) was recorded in treatment 3.Treatment 4 had the best feed conversion ratio (FCR) of 2.20, this was followed by treatment 3 with FCR of 2.52 while the worst FCR value (3.27) was recorded in treatment 5. There was a gradual increase in terms of FCR across the various treatment from Treatment 1 to treatment 5. However, FCR value decreased from 3.27 in treatment 5 to 3.06 in treatment 6. The highest relative weight gain (RWG) was recorded in treatment 4 (28.85) that was fed with diet containing 60% Lima beans meal. This treatment was not significantly different (P >0.05) from treatment 3 (14.71) but was significantly different (P<0.05) from the rest of the treatments. Diet containing 80% lima beans meal had the lowest RWG value of 4.80. The Survival rate was joint highest in treatment 2, 3, 4 and 6 (100%), followed by treatment 5 (90%) while treatment 1 (75%) had the lowest survival rate. The values gotten indicate that inclusion levels did not affect the survival of the fish. In conclusion, result obtained from this study showed that among the diets with toasted Lima bean meal, Treatment 4 with 60% inclusion rate had the best performance and feed utilization value. This further demonstrate that toasted Lima beans can partially replace Soya bean meal in the diet of Heteroclarias.
