EFFECTS OF EXPERIMENTAL DIETS ON THE BIOLOGY, PHYSIOLOGY, AND 43 NUTRITIONAL COMPOSITION OF GROMPHADORHINA PORTENTOSA (SCHAUM, 1853) 44 WITH POTENTIAL FOR USE IN ANIMAL FEED
Madagascar hissing cockroach; alternative diets; bromatology; biological profile; morphology; food sustainability; nutritional biochemistry
The Madagascar hissing cockroach, Gromphadorhina portentosa, has attracted increasing scientific and productive interest due to its potential as a model organism in biological studies and as an alternative nutrient source—particularly protein—for animal feed. The search for more sustainable food systems has driven the use of insects, which exhibit high feed conversion efficiency and lower environmental impact compared to conventional livestock production. In this context, the present study aimed to evaluate the influence of different agro-industrial diets on the biological, metabolic, and digestive histological performance of G. portentosa nymphs. Nymphs were fed a control diet based on wheat bran and experimental diets formulated with cottonseed meal, soybean meal, barley, DDG (Distiller’s Dried Grains), and DDGS (Distiller’s Dried Grains with Solubles). Initially, the diets were subjected to bromatological characterization. Subsequently, biological parameters—including survival, biomass gain, and morphometric development (body mass, insect size, and pronotum dimensions)—were assessed as indicators of growth and ontogenetic progression in newly hatched nymphs (0–24 h), monitored weekly over an 18-week experimental period. In parallel, biochemical analyses were conducted to determine body contents of total soluble proteins, lipids, glycogen, and total sugars, in addition to histological analyses of the midgut. The results showed that survival did not differ significantly among diets, whereas biological and metabolic performance was influenced by the nutritional composition of the substrates. Diets based on DDG and DDGS exhibited higher nutritional density, resulting in greater biomass gain, improved body development, and higher levels of energy reserves. Histological analyses indicated preservation of midgut epithelial organization in most treatments, while the cottonseed-based diet promoted structural alterations in the midgut and the barley-based diet induced intestinal epithelial metaplasia. Overall, DDG and DDGS stood out as the most efficient diets, highlighting the potential of G. portentosa nymphs for sustainable insect production systems aimed at animal feeding.