The past few decades, there has been a noticeable surge in the demand for seafood products, driven in part by the global population growth and increased apparent consumption. To address this escalating demand, shrimp farming has experienced significant expansion on a global scale. This expansion has led to an intensified need for protein in aquaculture animals’ feeds and a concurrent reduction in available proteins sources, such as fish meal.
Various alternatives have been explored to replace fish meal in feeds. Insect meals have demonstrated high nutritional value, serving as rich source of proteins, lipids, vitamins and minerals for shrimps. Given these factors, it becomes pertinent to assess whether insect meals could serve as a sustainable candidate for partially replacing fish meal in shrimp feeds.
To assess the influence of Black Soldier Fly (BSF) larvae defatted meal on feed digestibility in shrimp, we conducted a comprehensive evaluation. The digestibility of multiple meal fractions mixtures, each derived through distinct industrial processes and having diverse compositions, was determined. This assessment was based on a dual protocol for digestibility measurement, first in vitro (pH-stat method), and then in vivo on selected fractions incorporated in experimental feeds. This approach allows for rapidly testing various fractions while minimizing animal testing. The digestibility of the meals and mixtures were all above 85 % apparent protein digestibility and not significantly different (p values > 0.05), even if a trend to improve the digestibility was observed with some mixtures. Two experimental feeds were thus produced (Table 1) from the two best fractions, and their in vivo digestibility were determined using Pacific blue shrimp Penaeus stylirorstris juveniles for 56 days. Chrome oxide was used as inert marker in the feeds.
This study allowed us to assess whether BSF meal had an impact on feed digestibility compared with a control feed by evaluating the digestibility of proteins, lipids, energy, and minerals, as well as the effect on intestinal and hepatopancreatic microbiotas. This study also demonstrated the relevance of the in vitro approach as a simple and rapid way to test new protein sources in aquaculture as potential substitutes for fish meal.