Replacing Dietary Fish Meal with Defatted Black Soldier Fly (Hermetia illucens) Larvae Meal Affected Growth, Digestive Physiology and Muscle Quality of Tongue Sole (Cynoglossus semilaevis)

Abstract

For solving the global shortage of fish meal (FM) supplies from fisheries, the black soldier fly (Hermetia illucens) has become a new protein alternative in aquatic feeds. The present study investigated the effects of dietary inclusion of defatted H. illucens larvae meal (DBLM) on growth, serum biochemical parameters, digestive function, and muscle quality of tongue sole (Cynoglossus semilaevis). The feeding experiment consisted of five experimental diets: a control diet based on FM protein (H0) and four DBLM diets, substituting 25% (H25), 50% (H50), 75% (H75), and 100% (H100) of FM. C. semilaevis (initial weight 563.48 ± 22.81 g) were randomly allocated over five treatments in quadruplicate. After 65 days of feeding, the weight gain rate (WGR), specific growth rate (SGR), and protein efficiency ratio (PER) were significantly higher in H0 and H25 groups with less feed conversion ratio (FCR) and feed intake (FI). The concentrations of serum ALT, TG, T-CHO, ALB, and GLO and their ratio (i.e., A/G) in the H25 group were also significantly higher than those in the other DBLM diet-feeding groups. The digestive enzyme activities first increased (from 25% to 75%) and then decreased (from 75%) with the increased level of DBLM in diets. Meanwhile, there were significant improvements in the thickness of the intestinal longitudinal muscle (LM), circular muscle (CM), columnar epithelium (CE), and lamina propria (LP) in H25 C. semilaevis compared to the control group (p < 0.05). The fish from the other DBLM diets groups presented significant reductions in the thicknesses of LM, CM, CE, and LP, as well as the length of microvilli (ML) in a dose-dependent manner (p < 0.05). However, the substitution of FM increased up to 50% would result in intestinal structural damage. Moreover, the proximate compositions, antioxidant and water holding capacity, and muscular structures of C. semilaevis fillets were all significantly affected after substituting 25% FM with DBLM (p < 0.05). Except for the dry matter, moisture, ash, crude fat, and protein contents were significantly higher in H25 C. semilaevis muscles. The SOD activity in the H0 group was significantly lower than that in the H25 group. The CAT activity in C. semilaevis muscles prominently reduced along with the increase in DBLM content in feeding diets (p < 0.05). The water holding capacity of C. semilaevis fillets was best in the H25 group. In summary, the optimum proportion of DBLM with FM for feeding C. semilaevis may be around 25%.

Effect of Fish Meal Substitution with Black Soldier Fly (Hermetia illucens) on Growth Performance, Feed Stability, Blood Biochemistry, and Liver and Gut Morphology of Siamese Fighting Fish (Betta splendens)

“…Based on the study by Nya and Austin [88], ALB and GLOB contributed to a healthy system and function of plasma carriers. In addition, ALB and ALT are indicators of hepatocyte injury and liver necrosis [89]. The present findings showed that the 24.5% BSFL recorded the highest ALT compared to the other treatment groups.…”

Excessive level of dietary insect protein negatively changed growth metabolomic and transcriptomic profiles of largemouth bass (Micropterus salmoides)

“…It is imperative for the aquaculture industry to find substitutes for fishmeal in the feeds of farmed fishes due to decreasing natural resources and the increasing price of fishmeal. HI meal has been previously used to partially replace fishmeal in the feeds of fish species including gilthead seabream ( Sparus aurata ) ( Bosi et al., 2021 ; Randazzo et al., 2021 ), rainbow trout ( Oncorhynchus mykiss ) ( Rimoldi et al., 2019 ), tongue sole ( Cynoglossus semilaevis ) ( Li et al., 2022 ) and zebrafish ( Danio rerio ) ( Fronte et al., 2021 ). The effects of replacing fishmeal with HI meal depend on fish species and the amount of substitution.…”

“…Inclusion of HI meal (up to 30%) in the diets of rainbow trout was reported to improve fish health through influencing the intestinal bacterial community ( Rimoldi et al., 2019 ). In tongue sole ( C. semilaevis ), low-level (substituting 25% of fishmeal) dietary HI meal had positive effects on growth; however, the substitution of fishmeal up to 50% resulted in a significant decrease in growth, intestinal structural damage and abnormal liver function ( Li et al., 2022 ).…”

Effect of black soldier fly (Hermetia illucens) larvae meal as a fishmeal protein replacement on the growth, feed utilization, survival and whole-body composition of Black molly (Poecilia sphenops)

“…Few studies showed highest growth performance on 20% fishmeal replacement with the inclusion of 20gm BSFLM per 100gm of diet in Dusky kob fish (Madibana et al, 2020). Whereas it was 25% with the inclusion of 20.20gm and 14.41gm BSFLM per 100gm of diet in African catfish and Tongue Sole respectively (Azri et al, 2022;Li et al, 2022). Rawski et al (2020) and Aisyah et al (2022) stated that the best result of growth was found in 30% fishmeal substitution with 30gm and 19gm of BSFLM incorporation in 100gm of diet in case of sturgeon and red hybrid tilapia respectively.…”