Partial Replacement of Fishmeal with Black Soldier Fly Larvae Meal in Nile Tilapia Diets Improves Performance and Profitability in Earthen Pond

Abstract

Insect meals have the potential to be used as a source of nutrients in aquafeeds due to their high nutritional profile and cost effectiveness. The objective of this study was to elucidate the impact of black soldier fly larvae meal (BSFLM) as a replacement for fish meal (FM) on Nile tilapia (Oreochromis niloticus, L) growth performance, survival rate, somatic indexes and economic benefits. Four experimental diets were prepared; three with BSFLM as a substitute for FM at 25 % (T25 %), 50 % (T50 %) and 75 % (T75 %) and a control diet without BSFLM (T0 %, 100 % FM). A total of 360 fingerlings weighing about 20 - 30 gs each were assigned to twelve cages built in a 720m2 earthen pond, with 30 fingerlings in each cage in a completely randomized design with three replications in each treatment group. The fingerlings were fed the experimental diets for 26 weeks. The results showed that the treatment diets did not significantly affect body weight gain and daily feed intake (p > 0.05). However, treatment T50 % (52.16 g) had the highest body weight gain while treatment T75 % (46.00 g) had the lowest body weight gain even though not statistically different (p > 0.05). The body length also followed the same trend being higher in T50 % (16.50 cm) and lowest in T75 % (15.91 cm). The survival rate was significantly influenced (p < 0.05) by the diet treatment groups, while blood parameters, visceral somatic and hepatosomatic indexes did not vary significantly (p > 0.05) across the treatment diets. Return on investment and the cost-benefit ratio were significantly (p < 0.05) affected by the partial replacement of FM with BSFLM. Diets T25 %, T50 % and T75 % had higher (p < 0.05) profit margins when compared with diet T0 % (control). The study found that BSFLM can replace FM in diets for Nile tilapia without compromising on the growth performance of the fish while also increasing the profitability.