On the Digestibility of Mulberry Leaf Fed to Bombyx mori Larvae

Abstract

Considering that sericulture is an important branch of animal husbandry, not only for the production of silk but also as a valuable source of protein, it is necessary to constantly study the possibilities for its improvement as a branch of this domain. Therefore, the purpose of this paper is to assess the nutritional value and digestibility of mulberry leaves from the Kokuso 21 and Eforie varieties, as consumed by silkworms (Bombyx mori L., Bombicidae Family, Lepidoptera Order) during a summer study, in 2021. The Japanese variety (Kokuso 21) and the Romanian variety (Eforie) were used as food sources for the Triumf hybrid, developed in Romania; the larvae were divided in two batches of 300 larvae and each set was subdivided into six groups of 50 larvae, which were raised in paper trays based on their age and size. The research indicated that mulberry leaves have an average digestibility value of 54.46%; the aging process of the leaves altered their chemical composition, with most nutrients showing a decreasing trend in digestibility throughout the larval growth period, except for crude fiber, which remained unchanged in the early larval stages and increased to 26.78% towards the end of the experiment. Overall, the Kokuso 21 variety demonstrated superior nutrient digestibility compared to Eforie. An important finding from this study is the need for future research to determine the degree of nutrient metabolism and conversion into silk.