<b>Replacing fish meal by mealworm (<i>Tenebrio molitor</i>) on the growth performance and immunologic responses of white shrimp (<i>Litopenaeus vannamei</i>)

Abstract

The objective of this study was to determine the effect of replacing FM with mealworm (Tenebrio molitor) on the growth performance and immunologic responses of white shrimp. In addition, the toxicity of such replacement to white shrimp was measured. Mealworm was incorporated to partially or totally replace fish meal in diets for white shrimp. Experimental groups of shrimp with an average initial body weight of 2.39 ± 0.49 g were fed each of 4 isonitrogeneous diets formulated to include 0, 25, 50 and 100% (control, MW25, MW50 and MW100 respectively) of mealworm substituted for fish meal. After eight weeks of feeding trials, shrimp fed diets MW25, MW50 and MW100 had higher live weight gain (10.05 ± 3.06, 11.41 ± 2.08, and 10.36 ± 1.57, respectively), higher specific growth rate (2.56 ± 0.11, 2.79 ± 0.09, and 2.61 ± 0.07, respectively), and better feed conversion ratio (2.89 ± 0.08, 2.69 ± 0.09, and 2.72 ± 0.19, respectively) compared to those of shrimp fed control diet. Survival rate was 98% in all treatments. No toxicity was found in post-mortem pathophysiologic examinations. The levels of immune markers such as beta-glucan binding protein, prophenoloxidase and crustin associated with shrimp's cellular and humoral immunity were found to be higher in 25 and 50% mealworm replacement groups. These results clearly indicated that replacement of fish meal with 50% mealworm for shrimp diet was optimal in promoting the growth performance of shrimp without any adverse effect.

Replacing Fish Meal with Defatted Insect Meal (Yellow Mealworm Tenebrio molitor) Improves the Growth and Immunity of Pacific White Shrimp (Litopenaeus vannamei)

“…Choi et al (2018) reported significant improvements in the THC when insect meal fed shrimp (50% FM replacement) were challenged with the pathogen that causes white spot syndrome virus (WSSV) [21]. Similarly, in the present study, in pre-challenged shrimps, THC showed an improvement that positively correlated with the YM dietary levels.…”

“…Choi et al (2018) reported similar results when replacing FM with a full-fat T.molitor meal in Pacific white shrimp diet. The authors suggested that an insect meal improves growth performance of the shrimp because it contains essential amino acids [21].…”

“…In the present study, the inclusion of YM in experimental diets did not impact on the feed intake. It is interesting to note that in other nutritional studies, feed consumption was also not affected by dietary inclusion of mealworm protein [20,21].…”

“…However, in a study using black soldier fly larvae ( H. illucens ), FM replacement was limited to less than 25% of a diet for rainbow trout [18]. In contrast, all studies (including the present one) that used T. molitor as a dietary ingredient could completely replace FM in Pacific white shrimp diets [20,21], and some levels of FM substitution could even increase growth and feed conversion performances [21]. This was not the case in the study by Panini et al (2017) and we propose that the negative impact on nutrient digestibility, observed in the Panini study, was either due to the absence of processing of their meal and absence of amino acid supplementation (methionine and lysine) rather than to the presence of chitin, as the authors suggested.…”

“…Concerning shrimp, Cummins et al (2017) reported that a full-fat black soldier fly ( Hermetia illucens ) meal can replace up to 25% of FM without affecting shrimp growth [19]. Similarly, previous studies on T. molitor full-fat meal-based diets that were adequately supplemented with methionine, demonstrated similar or superior nutritional value and growth performance of Pacific white shrimp compared to the FM-based diet [20,21].…”