Synergistic Effect of Hermetia illucens Larval Meal and Moringa oleifera Leaf Meal on the Growth Performance of Clarias gariepinus

Abstract

Scarcity and high cost of fishmeal (FM) which is the main source of animal protein in fish feed have continued to challenge the aquaculture industry. This study therefore assessed the potentials of black soldier fly (Hermetia illucens) larvae meal and moringa leaf (Moringa oleifera) meal as cheaper and sustainable fishmeal alternatives in the diet of African catfish (Clarias gariepinus), a species widely farmed in Nigeria for its high fecundity and adaptational traits. The fish rearing experiment was carried out in Completely Randomised Design (CRD). Three diet formulations: a control diet (T1 100% fishmeal) and combination diets T2 (25% each BSFLM & MLM), T3 (50% each BSFLM & MLM) were each twice replicated and compared. Each replicate had fifteen fingerlings amounting to thirty fingerlings per treatment and a total of ninety fingerlings used in the experiment. The fingerlings were of the same age and average body weight (5.20g) and length (10.28cm). The fish were fed twice a day for a duration of 24 weeks. The mean values of water parameters throughout the period of fish feeding- pH 8.08, temperature 28.960C and dissolved oxygen 9.04 were within acceptable limits for the growth of African catfish. Parameters assessed included proximate of experimental diets, growth performance indices which included mean weight gain, mean length increase, and specific growth rate. Fish mortalities were recorded from each of the seven treatments within the experimental duration. The result for proximate of experimental diets showed that T1 had the highest crude protein (29.05%), carbohydrate (37.64 %), lipid (4.26%), fibre (3.49%); while the highest moisture was recorded by diet T3 (17.42%). There was a significant difference between the fibre and lipid extract of the experimental diets (p=0.00). The result showed that the mean weight gain of African catfish (C. gariepinus) varied among the combination treatments of black soldier fly larvae meal and moringa leaf meal at inclusion levels of 25% and 50% (T2 & T3) respectively. There was a marginally significant difference between the treatments (p = 0.055), the mean weight gain for T2 (25% each BSFL & MLM) group was 42.45±2.927 grams, while T3 (50% each BSFLM & MLM) group had a mean weight gain of 35.23±2.355 grams. The mean increase in length of African catfish (C. gariepinus) varied among the different treatments of combination diets of black soldier fly larvae meal and moringa leaf meal (BSFLM & MLM) T2 & T3 at inclusion levels of 25% and 50% respectively. Although there was no significant difference between the treatments (p = 0.208), the mean increase in length for T2 (25% each BSFLM & MLM) group was 20.57±0.54 cm, while T3 (50% each BSFLM & MLM) group had a mean increase of 19.53±0.63 cm. Generally, when compared to the control diet T1 (100% FM) with mean length and weight of 29.87±0.753cm and 139.89±7.65g respectively, diet T2 had a higher weight gain and mean length of (42.45±2.93g and 20.57±0.54cm) respectively than diet T3 (35.23±2.36g and 19.53±0.63cm), respectively. Result showed that the mean length and weight gains of African catfish (C. gariepinus) varied significantly among the treatments (p=0.000). Fish fed the control diet (T1) had the highest SGR value (17.59 ± 0.0000%) while the least SGR value was recorded for fish fed diet T3 (50% each BSFLM & MLM) (13.52 ± 0.0000, with significant differences among the means with P<0.05. It was concluded that that the combination of animal and plant proteins as a diet at inclusion levels of 25% and 50% to substitute fishmeal does not have the capacity to support growth in the African catfish due to poor synergy.