Zootechnical performance, feed efficiency and larval composition of Zophobas morio (Coleoptera: Tenebrionidae) fed with poultry litter-based diets

Abstract The yellow mealworm, super worm, and house cricket are among the most widely produced insects, with high feed conversion efficiency. However, their nutritional composition and development rate generally vary with environmental conditions. From an economic point of view, rearing conditions such as diet, temperature, and development time; insect performance such as mortality and nutritional value are the most important factors. In order to assess the development, growth, feed conversion efficiency, and chemical composition of Zophobas morio (Coleoptera: Tenebrionidae) larvae fed with diets containing poultry litter, an experiment was conducted. Five diets with varying levels of poultry litter inclusion (0, 25, 50, 75, and 100%) were used to replace the control diet (broiler feed), with five replicates containing 25 larvae per sample unit. Larval growth and development were assessed, and the chemical compositions of both the diet and Z. morio larvae were determined. Significant differences were observed among treatments for development time, survival rate, pupa weight, adult weight of Z. morio subjected to different poultry litter-based diets, as well as in the nutritional index bioassay. The longest development time and the highest larval mortality were observed in the 100% poultry litter-based diets. The highest percentage of crude protein in larval meal (%CP) was obtained with the addition of 25 and 50% poultry litter and was lowest with 100%. The incorporation of poultry litter into the diet of Z. morio has a multifaceted impact on growth and feed conversion efficiency. Elevated levels of poultry litter inclusion led to an extension in development time, yet food conversion efficiency attains optimization with an inclusion rate of up to 50%. Consequently, the decision regarding the proportion of poultry litter in the diet should be carefully weighed, taking into account breeding objectives, efficiency considerations, and cost factors. This ensures the attainment of an optimal balance between larval growth and nutritional efficiency.