House Cricket (Acheta domesticus) Meal as an Alternative Protein Source for Fattening Rabbits: Effects on Growth Performance, Nutrient Digestibility, Intestinal Morphology, and Histopathology

House cricket (Acheta domesticus) meal is a promising alternative protein source, but evidence regarding its nutritional value and effects in rabbits remains limited. This study aimed to (i) evaluate the effects of replacing part of the soybean meal with 3% A. domesticus meal on growth performance and intestinal and hepatic histology in growing rabbits, and (ii) determine the apparent total tract digestibility and nutritive value of A. domesticus meal in a separate digestibility experiment. In Experiment 1, 50 growing New Zealand White rabbits were fed a control diet or a diet containing 3% A. domesticus meal from weaning (30–35 d) to slaughtering (88–93 days). In Experiment 2, 24 rabbits were used to determine the apparent total tract digestibility and nutritive value of A. domesticus meal using a diet containing 7.5% cricket meal. The 3% inclusion level did not significantly affect growth performance or feed conversion ratio. It increased duodenal villus width and jejunal and ileal villus height and was associated with lower histological inflammation scores in the small intestine (all p < 0.05). However, greater cecal goblet cell hyperplasia and hepatic fatty degeneration were also observed (p < 0.05). In Experiment 2, the diet containing 7.5% cricket meal increased dry matter, organic matter, and crude protein digestibility (all p < 0.05). A. domesticus meal showed high protein digestibility (86.2%) but relatively low gross energy digestibility (41.4%) and a moderate digestible energy value (2499 kcal/kg DM). Overall, A. domesticus meal did not impair growth performance and provided highly digestible protein, but further research is needed to clarify its energy utilization and intestinal and hepatic effects before its use as a partial protein replacement in rabbit diets.