{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T09:24:15Z","timestamp":1787304255718,"version":"build-2736575974"},"reference-count":44,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T00:00:00Z","timestamp":1787270400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Insect-derived feed ingredients are increasingly considered alternative protein sources, but their time-dependent effects on digestive function remain unclear. This study evaluated how the duration of feeding a diet containing Cuban cricket meal (CCM) affected fecal bacterial enzyme activity and apparent nutrient digestibility in adult rabbits. Thirty-two New Zealand White male rabbits were allocated to four groups. The control group received a diet containing 14% soybean meal throughout the six-week trial, whereas experimental groups received soybean meal followed by a diet in which 10% CCM replaced soybean meal for the final two, four, or six weeks. It was found that the fecal enzymatic response depended on feeding duration. Short-term feeding induced limited changes, whereas longer feeding periods (four and six weeks) increased the activity of enzymes involved in the degradation of complex substrates, including chitin, and enhanced the extracellular activity of several enzymes. Digestibility of dry matter, crude protein, ether extract, and energy was unaffected. By contrast, neutral detergent fiber, acid detergent fiber, and acid detergent lignin digestibility increased after four and six weeks (p &lt; 0.001). These results could be interpreted as indirect evidence that rabbits\u2019 gut microbiota requires an adaptation period to effectively respond to insect-derived components.<\/jats:p>","DOI":"10.3390\/ani16162619","type":"journal-article","created":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T08:14:01Z","timestamp":1787300041000},"page":"2619","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The Effect of the Duration of Feeding a Diet Containing Cuban Cricket (Gryllus assimilis) Meal on Fecal Bacterial Enzyme Activity and Nutrient Digestibility in Adult Rabbits"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0948-3072","authenticated-orcid":false,"given":"Janusz","family":"Strychalski","sequence":"first","affiliation":[{"name":"Department of Fur-Bearing Animal Breeding and Game Management, University of Warmia and Mazury in Olsztyn, Oczapowskiego 2, 10-719 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0068-5970","authenticated-orcid":false,"given":"Jerzy","family":"Ju\u015bkiewicz","sequence":"additional","affiliation":[{"name":"InLife Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tryli\u0144skiego 18, 10-683 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5360-9755","authenticated-orcid":false,"given":"Andrzej","family":"Gugo\u0142ek","sequence":"additional","affiliation":[{"name":"Department of Fur-Bearing Animal Breeding and Game Management, University of Warmia and Mazury in Olsztyn, Oczapowskiego 2, 10-719 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,21]]},"reference":[{"key":"ref_1","unstructured":"United Nations Department of Economic and Social Affairs, Population Division (2022). World Population Prospects 2022: Summary of Results, United Nations. UN DESA\/POP\/2022\/TR\/NO. 3."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"145","DOI":"10.4995\/wrs.2024.22017","article-title":"Dietary inclusion of white lupine seeds and their byproducts in rabbits can contribute to EU agricultural sustainability: A review","volume":"32","author":"Volek","year":"2024","journal-title":"World Rabbit Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"100904","DOI":"10.1016\/j.animal.2023.100904","article-title":"Review: Recent advances in insect-based feeds: From animal farming to the acceptance of consumers and stakeholders","volume":"17","author":"Sogari","year":"2023","journal-title":"Animal"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.anifeedsci.2014.07.008","article-title":"State-of-the-art on use of insects as animal feed","volume":"197","author":"Makkar","year":"2014","journal-title":"Anim. Feed Sci. Technol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1093\/af\/vfad025","article-title":"Gut microbiota changes in insect-fed monogastric species: State-of-the-art and future perspectives","volume":"13","author":"Biasato","year":"2023","journal-title":"Anim. Front."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1461","DOI":"10.1038\/s41598-018-19940-8","article-title":"Chitin digestibility is dependent on feeding behaviors, which determine acidic chitinase mRNA levels in mammalian and poultry stomachs","volume":"8","author":"Tabata","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1993","DOI":"10.1007\/s12649-021-01645-1","article-title":"Purification of chitin from pupal exuviae of the black soldier fly","volume":"13","author":"Hahn","year":"2022","journal-title":"Waste Biomass Valor."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Pissard, A., Gofflot, S., Baeten, V., Lecler, B., Lorrette, B., Morin, J.-F., and Debode, F. (2025). Chitin assessment in insect-based products from reference methods to near-infrared models. Insects, 16.","DOI":"10.3390\/insects16090924"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"e00388-23","DOI":"10.1128\/msystems.00388-23","article-title":"Metagenomics uncovers dietary adaptations for chitin digestion in the gut microbiota of convergent myrmecophagous mammals","volume":"8","author":"Teullet","year":"2023","journal-title":"mSystems"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"131","DOI":"10.22358\/jafs\/91967\/2018","article-title":"Full-fat insect meals as feed additive: Effects on broiler chicken growth performance and gastrointestinal tract microbiota","volume":"27","author":"Rawski","year":"2018","journal-title":"J. Anim. Feed Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/j.anifeedsci.2017.08.012","article-title":"Gut antimicrobial effects and nutritional value of black soldier fly (Hermetia illucens L.) prepupae for weaned piglets","volume":"235","author":"Spranghers","year":"2018","journal-title":"Anim. Feed Sci. Technol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"txac018","DOI":"10.1093\/tas\/txac018","article-title":"Evaluation of black soldier fly larvae (Hermetia illucens) as a protein supplement for beef steers consuming low-quality forage","volume":"6","author":"Fukuda","year":"2022","journal-title":"Transl. Anim. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"116224","DOI":"10.1016\/j.anifeedsci.2025.116224","article-title":"In vitro and in vivo investigations on the use of yellow mealworm (Tenebrio molitor) as a novel protein feed ingredient for fattening lambs","volume":"320","author":"Angeles","year":"2025","journal-title":"Anim. Feed Sci. Technol."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Gugo\u0142ek, A., Kowalska, D., Strychalski, J., Ognik, K., and Ju\u015bkiewicz, J. (2021). The effect of dietary supplementation with silkworm pupae meal on gastrointestinal function, nitrogen retention and blood biochemical parameters in rabbits. BMC Vet. Res., 17.","DOI":"10.1186\/s12917-021-02906-w"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"151","DOI":"10.22319\/rmcp.v12i1.5455","article-title":"The effect of silkworm pupae and mealworm larvae meals as dietary protein components on performance indicators in rabbits","volume":"12","author":"Kowalska","year":"2021","journal-title":"Rev. Mex. Cienc. Pecu."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Volek, Z., Zita, L., Ad\u00e1mkov\u00e1, A., Ad\u00e1mek, M., Ml\u010dek, J., and Plach\u00fd, V. (2023). Dietary inclusion of crickets (Acheta domesticus) and yellow mealworm meal (Tenebrio molitor) in comparison with soybean meal: Effect on the growth, total tract apparent digestibility, and nitrogen balance of fattening rabbits. Animals, 13.","DOI":"10.3390\/ani13101637"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1017\/S1751731114002729","article-title":"Dietary fibres in the nutrition of the growing rabbit and recommendations to preserve digestive health: A review","volume":"9","author":"Gidenne","year":"2015","journal-title":"Animal"},{"key":"ref_18","unstructured":"(2026, August 07). INRAE-CIRAD-AFZ Feed Tables. Composition and Nutritive Values of Feeds for Cattle, Sheep, Goats, Pigs, Poultry, Rabbits, Horses and Salmonids. Available online: https:\/\/feedtables.com\/."},{"key":"ref_19","unstructured":"AOAC International (2006). Official Methods of Analysis of AOAC International, AOAC International. [18th ed.]."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3583","DOI":"10.3168\/jds.S0022-0302(91)78551-2","article-title":"Methods for dietary fibre, neutral detergent fibre and non-starch polysaccharides in relation to animal nutrition","volume":"74","author":"Robertson","year":"1991","journal-title":"J. Dairy Sci."},{"key":"ref_21","unstructured":"R Core Team (2025). R: A Language and Environment for Statistical Computing, R Foundation for Statistical Computing. Available online: https:\/\/www.R-project.org\/."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"104254","DOI":"10.1016\/j.tifs.2023.104254","article-title":"Unraveling the nutritional, biofunctional, and sustainable food application of edible crickets: A comprehensive review","volume":"143","author":"Zafar","year":"2024","journal-title":"Trends Food Sci. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1211","DOI":"10.2478\/aoas-2023-0031","article-title":"Influence of dietary chitosan supplementation on growth indicators, nutrient digestibility, immunity, cecal microbiota, and intestinal morphology of growing male rabbits","volume":"23","author":"Mahgoub","year":"2023","journal-title":"Ann. Anim. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Lopez-Santamarina, A., Mondragon, A.D.C., Lamas, A., Miranda, J.M., Franco, C.M., and Cepeda, A. (2020). Animal-origin prebiotics based on chitin: An alternative for the future? A critical review. Foods, 9.","DOI":"10.3390\/foods9060782"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1080\/1745039X.2021.1962171","article-title":"Performance indicators and gastrointestinal response of rabbits to dietary soybean meal replacement with silkworm pupae and mealworm larvae meals","volume":"75","author":"Strychalski","year":"2021","journal-title":"Arch. Anim. Nutr."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Zhang, A., Mo, X., Zhou, N., Wang, Y., Wei, G., Hao, Z., and Chen, K. (2020). Identification of chitinolytic enzymes in Chitinolyticbacter meiyuanensis and mechanism of efficiently hydrolyzing chitin to N-acetyl glucosamine. Front. Microbiol., 11.","DOI":"10.3389\/fmicb.2020.572053"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"766","DOI":"10.1038\/s41598-020-80782-4","article-title":"Individual fate and gut microbiome composition in the European wild rabbit (Oryctolagus cuniculus)","volume":"11","author":"Funosas","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1038\/nrmicro1817","article-title":"Polysaccharide utilization by gut bacteria: Potential for new insights from genomic analysis","volume":"6","author":"Flint","year":"2008","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Ramin, K.I., and Allison, S.D. (2019). Bacterial tradeoffs in growth rate and extracellular enzymes. Front. Microbiol., 10.","DOI":"10.3389\/fmicb.2019.02956"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"4306","DOI":"10.1128\/JB.187.13.4306-4314.2005","article-title":"Mechanisms of protein export across the bacterial outer membrane","volume":"187","author":"Kostakioti","year":"2005","journal-title":"J. Bacteriol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"600","DOI":"10.1080\/09168451.2018.1444467","article-title":"Flavonoid metabolism: The interaction of metabolites and gut microbiota","volume":"82","author":"Murota","year":"2018","journal-title":"Biosci. Biotechnol. Biochem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1111\/1574-6968.12348","article-title":"\u03b2-Glucosidase activities of lactic acid bacteria: Mechanisms, impact on fermented food and human health","volume":"352","author":"Michlmayr","year":"2014","journal-title":"FEMS Microbiol. Lett."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1294","DOI":"10.1016\/j.ijbiomac.2019.10.140","article-title":"Microbial production and biotechnological applications of \u03b1-galactosidase","volume":"150","author":"Bhatia","year":"2020","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1007\/s10930-023-10117-5","article-title":"Recombinant production and biochemical characterization of thermostable arabinofuranosidase from acidothermophilic Alicyclobacillus acidocaldarius","volume":"42","author":"Akkaya","year":"2023","journal-title":"Protein J."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"501","DOI":"10.1007\/s00580-023-03447-4","article-title":"The role of insects in promoting the health and gut status of poultry","volume":"32","author":"Malematja","year":"2023","journal-title":"Comp. Clin. Pathol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"16372","DOI":"10.1038\/s41598-018-34678-z","article-title":"\u03b2-Glucuronidases of opportunistic bacteria are the major contributors to xenobiotic-induced toxicity in the gut","volume":"8","author":"Dashnyam","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"101094","DOI":"10.1016\/j.plipres.2021.101094","article-title":"Bile acids and their receptors in metabolic disorders","volume":"82","author":"Fiorucci","year":"2021","journal-title":"Prog. Lipid Res."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2172671","DOI":"10.1080\/19490976.2023.2172671","article-title":"Bile acids as modulators of gut microbiota composition and function","volume":"15","author":"Larabi","year":"2023","journal-title":"Gut Microbes"},{"key":"#cr-split#-ref_39.1","unstructured":"EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA), Turck, D., Bohn, T., Castenmiller, J., De Henauw, S., Hirsch-Ernst, K.I., Maciuk, A., Mangelsdorf, I., McArdle, H.J., and Naska, A. (2022). Scientific opinion on the safety of frozen and freeze-dried formulations of the lesser mealworm (Alphitobius diaperinus larva) as a novel food pursuant to Regulation"},{"key":"#cr-split#-ref_39.2","unstructured":"(EU) 2015\/2283. EFSA J., 20, 7325."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"5069","DOI":"10.1002\/jsfa.9044","article-title":"New methods for high-accuracy insect chitin measurement","volume":"98","author":"Hahn","year":"2018","journal-title":"J. Sci. Food Agric."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Abenaim, L., and Conti, B. (2025). Harnessing chitin from edible insects for livestock nutrition. Insects, 16.","DOI":"10.3390\/insects16080799"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"463","DOI":"10.1079\/BJN19950048","article-title":"Distribution of activity of hydrolytic enzymes in the digestive tract of rabbits","volume":"73","author":"Marounek","year":"1995","journal-title":"Br. J. Nutr."},{"key":"ref_43","first-page":"199","article-title":"Measurement of the bacterial fibrolytic activity in the caecum and in the soft faeces of the rabbit","volume":"Volume 1","author":"Lebas","year":"1996","journal-title":"Proceedings of the 6th World Rabbit Congress, Toulouse, France, 9\u201312 July 1996"}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/16\/2619\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T08:32:01Z","timestamp":1787301121000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/16\/2619"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,21]]},"references-count":44,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["ani16162619"],"URL":"https:\/\/doi.org\/10.3390\/ani16162619","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,21]]}}}