Potential of Full-Fat Silkworm-Based Diets for Laying Quails: Performance and Egg Physical Quality

SIMPLE SUMMARY: Insects can represent a sustainable and alternative feed ingredient to conventional feedstuffs, thanks to a rich nutritional profile, and possibly helping to reduce the feed-food competition. Among various insect species, the mulberry silkworm is of great interest. Silkworm chrysalis is a silk industry by-product, and it is a rich source of high-quality protein and healthy oil. At present, research is required to understand its potential in different food-producing animal species, optimum inclusion levels, and possible side effects. The present research contributes to provide a better understanding of the potential of silkworm chrysalis as a feedstuff for laying quails. The results of the present study demonstrated that the silkworm chrysalis meal could be used in laying quail feed formulation up to 12% inclusion, providing optimal performance and egg physical quality. ABSTRACT: The present research was conducted to determine the optimal inclusion level of full-fat silkworm chrysalis meal (SWM) into laying quails’ diets, focusing on performance traits and egg physical quality. A total of 240 31-day-old female Japanese quails were randomly assigned to four dietary groups (12 replicates/treatment; 5 quails/replicate); quails were initially fed a standard commercial diet for pullets until 63 days of age. When oviposition started, the experimental groups received the following diets: a conventional corn and soybean-based diet (control diet—C) and three other diets, including 4%, 8%, or 12% of full-fat SWM (SWM4, SWM8, SWM12, respectively). Experimental diets were provided until quails reached 119 days of age. Birds displayed satisfactory productive performance throughout the trial. SWM12 and SWM8 had higher (p < 0.001) egg production but also a higher feed conversion ratio compared to C. At the end of the trial, the eggs edible portion increased, and shell weight decreased with increasing the SWM dietary inclusion level (p < 0.001). At the same time, SWM12 displayed an increase in albumen pH (p < 0.05), even though in the normal range for quail egg. Overall, full-fat SWM (up to 12%) can be considered a promising feed ingredient for laying quails, although higher inclusion levels (>8%) require special attention because SWM also contains anti-nutritional factors.