Francesca Falcinelli

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.

The search for sustainable feed ingredients has increased interest in insect-derived proteins for livestock production. This study evaluated the effects of replacing 3% soybean meal with house cricket (Acheta domesticus) meal on carcass traits, meat quality, proximate composition, and fatty acid profile of growing rabbits. Twenty-four weaned New Zealand White rabbits were assigned to either a control (CNT) or a cricket meal diet (ADM) from 35 to 85 days of age. Physical meat quality was evaluated in the Longissimus thoracis et lumborum (LTL), while proximate composition and fatty acid profile were determined in LTL and thigh muscles. Carcass performance was not affected by dietary treatment, whereas the cricket meal diet increased adiposity, resulting in greater scapular and perirenal fat deposition (p < 0.001) and a higher fat proportion in the hind leg (p = 0.011). Physical meat quality traits were unaffected, except for higher cooking loss in ADM-fed rabbits (p = 0.039). Cricket meal increased crude fat and modified the fatty acid composition by increasing n-6 PUFA (p = 0.013) and reducing n-3 PUFA (p < 0.001), resulting in a less favorable n-6/n-3 ratio. Overall, cricket meal modified lipid deposition and fatty acid composition without compromising carcass performance, although its greater lipid contribution should be considered when interpreting these effects.

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are recognized for their beneficial effects on male fertility. This study evaluated the protective effects of dietary n-3 PUFAs from extruded linseed, alone or combined with the alga Padina pavonica, against in vitro lipopolysaccharide (LPS)-induced sperm dysfunction in rabbits. Twelve bucks were fed for 60 days a control diet (CNT), a diet containing 5% extruded linseed (L), or 5% extruded linseed plus 0.2% P. pavonica extract (LPP). Ejaculates were exposed in vitro to increasing LPS concentrations (0, 400, and 600 µg/mL), and sperm motility was evaluated at 0, 1, 2, and 4 h using computer-assisted sperm analysis. LPS markedly impaired sperm motility in the CNT group, increasing the percentage of static spermatozoa (p < 0.001) and reducing sperm progressive motility (p < 0.001), with complete immobility observed at 600 µg/mL after 4 h. Conversely, sperm from L and LPP groups maintained significantly higher progressive motility, lower static sperm, and improved kinematic parameters throughout the LPS challenge (p < 0.05). Dietary n-3 PUFA supplementation also attenuated LPS-induced TLR4 activation and reduced lipid peroxidation, as indicated by lower seminal TBARS levels. No histological alterations were detected in the male reproductive tract. These findings indicate that n-3 PUFA supplementation, particularly linseed combined with algae, mitigates LPS-induced sperm dysfunction in vitro.