{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,7]],"date-time":"2026-09-07T21:09:50Z","timestamp":1788815390351,"version":"build-2803163510"},"reference-count":31,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,21]],"date-time":"2026-01-21T00:00:00Z","timestamp":1768953600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Natural Science Foundation of Gansu Province","award":["24JRRA024"],"award-info":[{"award-number":["24JRRA024"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Background\/Objectives: Apple pomace, a major by-product of juice production, represents both an environmental burden and an underutilized resource. This study aimed to enhance the nutritional value of apple pomace via solid-state fermentation (SSF) to develop a functional feed ingredient and systematically evaluate its effects on growth, metabolism, and intestinal health in weaned piglets. Methods: Apple pomace was fermented using a multi-species consortium (Geotrichum candidum, Saccharomyces cerevisiae, Rhizopus oryzae, Bacillus subtilis, and Trichoderma viride). A total of 180 weaned piglets were fed iso-nitrogenous diets containing 0, 2, 4, 6, 8, or 10% fermented apple pomace for 35 days. Growth performance, serum biochemical and immuno-antioxidant indices, diarrhea incidence, jejunal morphology, and fecal microbiota were analyzed. Results: Dietary fermented apple pomace supplementation showed dose-dependent effects. The 8% fermented apple pomace group exhibited optimal growth performance, with increased average daily gain and feed intake and reduced feed-to-gain ratio (p &lt; 0.05). Serum analysis indicated enhanced protein synthesis, antioxidant capacity (T-AOC, SOD, GSH-Px), and immunoglobulin levels (IgA, IgG, IgM), along with reduced urea nitrogen and oxidative stress marker MDA. This group also had the lowest diarrhea rate, associated with improved jejunal villus morphology. Microbiota analysis revealed that 8% fermented apple pomace effectively increased \u03b1-diversity, promoted beneficial bacteria (e.g., lactic acid bacteria and butyrate-producing Clostridium sensu stricto_1), and suppressed pathogens (Escherichia coli, Salmonella, Streptococcus). Conclusions: Multi-species SSF successively enhanced the nutritional profile of apple pomace. Inclusion at 8% showed the most favorable response in terms of growth performance, metabolic profile, and immune\u2013antioxidant status in weaned piglets, mediated through improved intestinal morphology and targeted modulation of the gut microbiota toward a more diverse and beneficial ecosystem. These findings support the high-value, functional utilization of apple pomace as a feed additive in swine nutrition.<\/jats:p>","DOI":"10.3390\/ani16020334","type":"journal-article","created":{"date-parts":[[2026,1,23]],"date-time":"2026-01-23T14:58:40Z","timestamp":1769180320000},"page":"334","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Dose-Dependent Responses of Weaned Piglets to Multi-Species Solid-State Fermented Apple Pomace: Enhanced Growth Performance, Intestinal Health, and Gut Microbiota Modulation"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0066-4723","authenticated-orcid":false,"given":"Jiongjie","family":"He","sequence":"first","affiliation":[{"name":"Key Laboratory of New Animal Drug Project of Gansu Province, Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture and Rural Affairs, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agriculture Sciences, Lanzhou 730050, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shengyi","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of New Animal Drug Project of Gansu Province, Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture and Rural Affairs, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agriculture Sciences, Lanzhou 730050, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e70988","DOI":"10.1002\/fsn3.70988","article-title":"Optimization of Pre-Treatments to Overcome Stickiness-Related Hurdles and Enhance Drying Efficiency in Apple Pomace","volume":"13","author":"Won","year":"2025","journal-title":"Food Sci. Nutr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"17932","DOI":"10.1007\/s11356-023-28479-9","article-title":"Sustainable utilization of apple pomace and its emerging potential for development of functional foods","volume":"31","author":"Asif","year":"2024","journal-title":"Environ. Sci. Pollut. Res. Int."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1080\/07388550802368895","article-title":"Processing of apple pomace for bioactive molecules","volume":"28","author":"Bhushan","year":"2008","journal-title":"Crit. Rev. Biotechnol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1080\/07388550801913840","article-title":"Apple pomace: A versatile substrate for biotechnological applications","volume":"28","author":"Vendruscolo","year":"2008","journal-title":"Crit. Rev. Biotechnol."},{"key":"ref_5","first-page":"S28","article-title":"Fractionation of polyphenol-enriched apple juice extracts to identify constituents with cancer chemopreventive potential","volume":"52","author":"Rabetafika","year":"2008","journal-title":"Mol. Nutr. Food Res."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"100589","DOI":"10.1016\/j.animal.2022.100589","article-title":"Doreau MMicrobial colonisation of tannin-rich tropical plants: Interplay between degradability, methane production and tannin disappearance in the rumen","volume":"16","author":"Rira","year":"2022","journal-title":"Animal"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e70070","DOI":"10.1111\/1541-4337.70070","article-title":"Solid-state fermentation: Bioconversions and impacts on bioactive and nutritional compounds in oats","volume":"23","author":"Green","year":"2024","journal-title":"Compr. Rev. Food Sci. Food Saf."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1153","DOI":"10.1002\/jobm.202300218","article-title":"Application of solid-state fermentation using mushrooms for the production of animal feed","volume":"63","author":"Rothmann","year":"2023","journal-title":"J. Basic Microbiol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1496","DOI":"10.1007\/s12010-021-03727-1","article-title":"Bioconversion of Apple Pomace into Microbial Protein Feed Based on Extrusion Pretreatment","volume":"194","author":"Yang","year":"2022","journal-title":"Appl. Biochem. Biotechnol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1007\/978-1-61779-433-9_17","article-title":"Recombinant protein production in yeasts","volume":"824","author":"Mattanovich","year":"2012","journal-title":"Methods Mol. Biol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1016\/j.aninu.2017.12.004","article-title":"Gastrointestinal tract (gut) health in the young pig","volume":"4","author":"Pluske","year":"2018","journal-title":"Anim. Nutr."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1111\/j.1439-0396.2012.01284.x","article-title":"Gastrointestinal health and function in weaned pigs: A review of feeding strategies to control post-weaning diarrhoea without using in-feed antimicrobial compounds","volume":"97","author":"Heo","year":"2013","journal-title":"J. Anim. Physiol. Anim. Nutr."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1499","DOI":"10.2527\/2004.8251499x","article-title":"Increasing weaning age improves pig performance in a multisite production system","volume":"82","author":"Main","year":"2004","journal-title":"J. Anim. Sci."},{"key":"ref_14","unstructured":"National Research Council (2012). Nutrient Requirements of Swine: 11th Revised Edition, The National Academies Press."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"124990","DOI":"10.1016\/j.watres.2025.124990","article-title":"MicrobiomePrime: A primer pair selection tool for microbial source tracking validated on a comprehensive collection of animal gut and fecal waste microbiomes","volume":"289","author":"Zlender","year":"2026","journal-title":"Water Res."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Hadj, S.J., Bertani, G., Levante, A., Vezzosi, F., Ricci, A., Bernini, V., and Lazzi, C. (2021). Fermentation of Agri-Food Waste: A Promising Route for the Production of Aroma Compounds. Foods, 10.","DOI":"10.3390\/foods10040707"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.mimet.2019.04.003","article-title":"A comparison of methods for enumerating bacteria in direct fed microbials for animal feed","volume":"160","author":"Gorsuch","year":"2019","journal-title":"J. Microbiol. Methods"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"100370","DOI":"10.1016\/j.vas.2024.100370","article-title":"Assessment of the digestibility, growth performance, hematological and serum biochemical profile of Bandjock Local Pigs (BLP) and Duroc X Large White pigs (DLW)","volume":"25","author":"Maafo","year":"2024","journal-title":"Vet. Anim. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"101189","DOI":"10.1016\/j.animal.2024.101189","article-title":"Impact of dietary Laminaria digitata with alginate lyase or carbohydrase mixture on nutrient digestibility and gut health of weaned piglets","volume":"18","author":"Ribeiro","year":"2024","journal-title":"Animal"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"108299","DOI":"10.1016\/j.jnutbio.2019.108299","article-title":"Apple polyphenols induce browning of white adipose tissue","volume":"77","author":"Tamura","year":"2020","journal-title":"J. Nutr. Biochem."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Liu, Z., Li, N., Zhou, X., Zheng, Z., Zhang, C., Liang, S., Li, Y., Yan, J., Li, Q., and Mu, S. (2022). Effects of Fermented Bamboo Powder Supplementation on Serum Biochemical Parameters, Immune Indices, and Fecal Microbial Composition in Growing-Finishing Pigs. Animals, 12.","DOI":"10.3390\/ani12223127"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2069","DOI":"10.4155\/fmc-2017-0109","article-title":"Anti-inflammatory and antioxidative effects of Camellia oleifera Abel components","volume":"9","author":"Xiao","year":"2017","journal-title":"Future Med. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1017\/S0007114519002873","article-title":"In vitro prebiotic potential of agricultural by-products on intestinal fermentation, gut barrier and inflammatory status of piglets","volume":"123","author":"Uerlings","year":"2020","journal-title":"Br. J. Nutr."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"650","DOI":"10.1016\/0022-3468(90)90356-E","article-title":"The physiology of adaptation to small bowel resection in the pig: An integrated study of morphological and functional changes","volume":"25","author":"Sigalet","year":"1990","journal-title":"J. Pediatr. Surg."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3139","DOI":"10.1080\/10408398.2022.2130160","article-title":"The role of dietary fibers in regulating appetite, an overview of mechanisms and weight consequences","volume":"64","author":"Akhlaghi","year":"2024","journal-title":"Crit. Rev. Food Sci. Nutr."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Yang, Q., Huang, X., Zhao, S., Sun, W., Yan, Z., Wang, P., Li, S., Huang, W., Zhang, S., and Liu, L. (2017). Structure and Function of the Fecal Microbiota in Diarrheic Neonatal Piglets. Front. Microbiol., 8.","DOI":"10.3389\/fmicb.2017.00502"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1186\/s40104-022-00790-4","article-title":"Maintenance of gut microbiome stability for optimum intestinal health in pigs\u2014A review","volume":"13","author":"Upadhaya","year":"2022","journal-title":"J. Anim. Sci. Biotechnol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1080\/1745039X.2017.1291202","article-title":"Interactive effects of protein and carbohydrates on production of microbial metabolites in the large intestine of growing pigs","volume":"71","author":"Taciak","year":"2017","journal-title":"Arch. Anim. Nutr."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1093\/advances\/nmx009","article-title":"Butyrate: A double-edged sword for health?","volume":"9","author":"Liu","year":"2018","journal-title":"Adv. Nutr."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2387","DOI":"10.1002\/jcsm.13573","article-title":"Short-chain fatty acids enhance muscle mass and function through the activation of mTOR signalling pathways in sarcopenic mice","volume":"15","author":"Liu","year":"2024","journal-title":"J. Cachexia Sarcopenia Muscle"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"631","DOI":"10.1007\/s00018-012-1070-x","article-title":"Regulation of intestinal epithelial permeability by tight junctions","volume":"70","author":"Suzuki","year":"2013","journal-title":"Cell. Mol. Life Sci."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/2\/334\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T05:14:30Z","timestamp":1769490870000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/2\/334"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,21]]},"references-count":31,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,1]]}},"alternative-id":["ani16020334"],"URL":"https:\/\/doi.org\/10.3390\/ani16020334","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,21]]}}}