{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:31:03Z","timestamp":1787027463979,"version":"build-2736575974"},"reference-count":57,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,12,21]],"date-time":"2025-12-21T00:00:00Z","timestamp":1766275200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key Research and Development Program of China","award":["2021YFD1300402"],"award-info":[{"award-number":["2021YFD1300402"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["32202730"],"award-info":[{"award-number":["32202730"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["32172777"],"award-info":[{"award-number":["32172777"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["U24A20447"],"award-info":[{"award-number":["U24A20447"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Guangdong Province\u2019s Special Fund for Rural Revitalization Strategy","award":["2025TS-3-1"],"award-info":[{"award-number":["2025TS-3-1"]}]},{"name":"CARS","award":["CARS-35"],"award-info":[{"award-number":["CARS-35"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>The objective of this study is to evaluate the effects of crude protein (CP) levels and antibiotics in feed on the growth performance, body composition, nutrient digestion and absorption, gut health, and microbiota of weaned piglets. A total of 100 piglets (Duroc \u00d7 Landrace \u00d7 Yorkshire, weaned at day 21) with an initial weight of 6.39 \u00b1 0.03 kg were randomly assigned to four treatments and fed with 18% CP antibiotic-free diets, 18% CP with antibiotics diets, 24% CP antibiotic-free diets, and 24% CP with antibiotics diets for 0\u201314 d (S1). Furthermore, the piglets were fed with an identical diet (19% CP and without antibiotics) starting day 15 until they reached 25 kg (S2). Results indicated that the average daily gain (ADG) and gain feed ratio (G:F) during the S1 phase as well as BW at day 14, were significantly decreased (p &lt; 0.05) in the 18% CP group compared with the 24% CP group. Similarly, piglets in the 18% CP group showed a significantly decreased body protein content and body water, protein deposition rates at the S1 phase, and significantly improved the body lipid content and deposition rate but not (p &gt; 0.05) at the S2 phase. The 18% CP group demonstrated significantly increased (p &lt; 0.05) serum concentrations of Threonine, Valine, Isoleucine, and Lysine in weaned piglets during the S1 phase, while Glycine concentration significantly decreased, and no significant (p &gt; 0.05) effects were observed in the S2 phase. Furthermore, dietary antibiotic supplementation had no effect on (p &gt; 0.05) piglet growth performance, body composition, nutrient digestion, and metabolism throughout the entire trial period. In the absence of antibiotics, compared to the 24% CP diet group, the piglets fed with an 18% CP diet significantly increased the relative abundance of Lactobacillus in the colon of weaned piglets upon reaching 25 kg BW (p &lt; 0.05). Compared to the diet without added antibiotics, the addition of antibiotics to the diet significantly decreased the relative abundance of Pseudoramibacter in the colon of weaned piglets on day 14. No significant (p &gt; 0.05) difference was observed in intestinal morphology or gastrointestinal pH among the groups. In conclusion, lower dietary protein levels in the early post-weaning period reduced growth performance and promoted gut microbiota balance, and compensatory growth occurred after returning to higher protein levels two weeks after weaning.<\/jats:p>","DOI":"10.3390\/ani16010024","type":"journal-article","created":{"date-parts":[[2025,12,22]],"date-time":"2025-12-22T08:35:27Z","timestamp":1766392527000},"page":"24","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The Role of CP Level and Interaction with Antibiotics in the Post-Weaning Piglets\u2019 Diet: Growth Performance, Body Composition, Nutrient Digestion, and Intestinal Health"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-9020-4984","authenticated-orcid":false,"given":"Rui","family":"Wang","sequence":"first","affiliation":[{"name":"State Key Laboratory of Swine and Poultry Breeding Industry, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lei","family":"Hou","sequence":"additional","affiliation":[{"name":"Guangxi State Farms Yongxin Animal Husbandry Group Co., Ltd., Nanning 530022, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qiwen","family":"Wu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Swine and Poultry Breeding Industry, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1595-7468","authenticated-orcid":false,"given":"Xiaolu","family":"Wen","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Swine and Poultry Breeding Industry, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8036-1356","authenticated-orcid":false,"given":"Yunxia","family":"Xiong","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Swine and Poultry Breeding Industry, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xuefen","family":"Yang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Swine and Poultry Breeding Industry, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaiguo","family":"Gao","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Swine and Poultry Breeding Industry, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zongyong","family":"Jiang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Swine and Poultry Breeding Industry, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuting","family":"Cao","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Swine and Poultry Breeding Industry, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Li","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Swine and Poultry Breeding Industry, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Limbach, J.R., Espinosa, C.D., Perez-Calvo, E., and Stein, H.H. (2021). Effect of dietary crude protein level on growth performance, blood characteristics, and indicators of intestinal health in weanling pigs. J. Anim. Sci., 99.","DOI":"10.1093\/jas\/skab166"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1228","DOI":"10.5713\/ab.22.0440","article-title":"Effects of different levels of dietary crude protein on growth performance, blood profiles, diarrhea incidence, nutrient digestibility, and odor emission in weaning pigs","volume":"36","author":"Kim","year":"2023","journal-title":"Anim. Biosci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"100195","DOI":"10.1016\/j.fochx.2021.100195","article-title":"What we know about protein gut metabolites: Implications and insights for human health and diseases","volume":"13","year":"2022","journal-title":"Food Chem. X"},{"key":"ref_4","first-page":"366","article-title":"Effect of different levels of fiber and protein on growth performance and fecal characteristics in weaning pigs","volume":"44","author":"Yun","year":"2017","journal-title":"Korean J. Agric. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3303","DOI":"10.2527\/jas.2007-0105","article-title":"Effect of dietary protein content on ileal amino acid digestibility, growth performance, and formation of microbial metabolites in ileal and cecal digesta of early-weaned pigs","volume":"85","author":"Htoo","year":"2007","journal-title":"J. Anim. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3337","DOI":"10.2527\/jas.2006-076","article-title":"The effect of dietary protein and fermentable carbohydrates levels on growth performance and intestinal characteristics in newly weaned piglets","volume":"84","author":"Bikker","year":"2006","journal-title":"J. Anim. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Wu, S., Bhat, Z.F., Gounder, R.S., Mohamed Ahmed, I.A., Al-Juhaimi, F.Y., Ding, Y., and Bekhit, A.E.A. (2022). Effect of Dietary Protein and Processing on Gut Microbiota-A Systematic Review. Nutrients, 14.","DOI":"10.3390\/nu14030453"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1016\/j.aninu.2023.12.010","article-title":"Dietary nutrition, intestinal microbiota dysbiosis and post-weaning diarrhea in piglets","volume":"17","author":"Han","year":"2024","journal-title":"Anim. Nutr."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1186\/2049-1891-4-19","article-title":"The biological stress of early weaned piglets","volume":"4","author":"Campbell","year":"2013","journal-title":"J. Anim. Sci. Biotechnol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1081\/ABIO-120005767","article-title":"Why and how antibiotics are used in swine production","volume":"13","author":"Cromwell","year":"2002","journal-title":"Anim. Biotechnol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1016\/j.pop.2018.05.006","article-title":"Emergence of Global Antibiotic Resistance","volume":"45","author":"Morehead","year":"2018","journal-title":"Prim. Care"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Nhung, N.T., Cuong, N.V., Thwaites, G., and Carrique-Mas, J. (2016). Antimicrobial Usage and Antimicrobial Resistance in Animal Production in Southeast Asia: A Review. Antibiotics, 5.","DOI":"10.3390\/antibiotics5040037"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Cardinal, K.M., Andretta, I., da Silva, M.K., Stefanello, T.B., Schroeder, B., and Ribeiro, A.M.L. (2021). Estimation of productive losses caused by withdrawal of antibiotic growth promoter from pig diets\u2014Meta-analysis. Sci. Agric., 78.","DOI":"10.1590\/1678-992x-2020-0266"},{"key":"ref_14","unstructured":"National Research Council (2012). Nutrient Requirements of Swine: Eleventh Revised Edition, The National Academies Press."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"334","DOI":"10.1007\/s11250-023-03742-w","article-title":"Nutrient digestibility and nitrogen balance in different pig breeds fed raw, sprouted, or roasted (Vigna unguiculata) diets","volume":"55","author":"Lubisi","year":"2023","journal-title":"Trop. Anim. Health Prod."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Hou, L., Wang, L., Qiu, Y., Xiong, Y., Xiao, H., Yi, H., Wen, X., Lin, Z., Wang, Z., and Yang, X. (2021). Effects of Protein Restriction and Subsequent Realimentation on Body Composition, Gut Microbiota and Metabolite Profiles in Weaned Piglets. Animals, 11.","DOI":"10.3390\/ani11030686"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4072","DOI":"10.2527\/jas.2011-4793","article-title":"Characterizing growth and carcass composition differences in pigs with varying weaning weights and postweaning performance","volume":"90","author":"Jones","year":"2012","journal-title":"J. Anim. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"He, Z., Zhan, X., Cao, S., Wen, X., Hou, L., Liu, S., Zheng, H., Gao, K., Yang, X., and Jiang, Z. (2023). Effect of Miscellaneous Meal Replacements for Soybean Meal on Growth Performance, Serum Biochemical Parameters, and Gut Microbiota of 50\u201375 kg Growing Pigs. Animals, 13.","DOI":"10.3390\/ani13223499"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1079\/ASC200643","article-title":"The effect of dietary protein supply on the performance and risk of post-weaning enteric disorders in newly weaned pigs","volume":"82","author":"Wellock","year":"2006","journal-title":"Anim. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1080\/10495390600957191","article-title":"Reduced use of antibiotic growth promoters in diets fed to weanling pigs: Dietary tools, part 2","volume":"17","author":"Stein","year":"2006","journal-title":"Anim. Biotechnol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2463","DOI":"10.1017\/S1751731119000776","article-title":"Protein restriction and succedent realimentation affecting ileal morphology, ileal microbial composition and metabolites in weaned piglets","volume":"13","author":"Shi","year":"2019","journal-title":"Anim. Int. J. Anim. Biosci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1016\/j.livsci.2010.09.007","article-title":"Growth performance and antibiotic tolerance patterns of nursery and finishing pigs fed growth-promoting levels of antibiotics","volume":"136","author":"Holt","year":"2011","journal-title":"Livest. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Diana, A., Boyle, L.A., Leonard, F.C., Carroll, C., Sheehan, E., Murphy, D., and Manzanilla, E.G. (2019). Removing prophylactic antibiotics from pig feed: How does it affect their performance and health?. BMC Vet. Res., 15.","DOI":"10.1186\/s12917-019-1808-x"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1046\/j.1439-0450.2002.00574.x","article-title":"Field evaluation of the effect of in-feed doxycycline for the control of ileitis in weaned piglets","volume":"49","author":"Kyriakis","year":"2002","journal-title":"J. Vet. Med. B Infect. Dis. Vet. Public Health"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2542","DOI":"10.2527\/2001.79102542x","article-title":"Evaluation of conjugated linoleic acid and dietary antibiotics as growth promotants in weanling pigs","volume":"79","author":"Weber","year":"2001","journal-title":"J. Anim. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"324","DOI":"10.2527\/jas.2007-0086","article-title":"Commercial validation of the true ileal digestible lysine requirement for eleven- to twenty-seven-kilogram pigs","volume":"86","author":"Kendall","year":"2008","journal-title":"J. Anim. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1016\/j.anifeedsci.2010.12.002","article-title":"Carcass traits and organ weights of 10\u201325-kg body weight Iberian pigs fed diets with different protein-to-energy ratio","volume":"164","author":"Aguinaga","year":"2011","journal-title":"Anim. Feed Sci. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"394","DOI":"10.1017\/S1751731116001634","article-title":"Impact of amino acid and CP restriction from 20 to 140 kg BW on performance and dynamics in empty body protein and lipid deposition of entire male, castrated and female pigs","volume":"11","author":"Stoll","year":"2017","journal-title":"Anim. Int. J. Anim. Biosci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1016\/j.livsci.2006.09.021","article-title":"The effect of dietary protein supply on carcass composition, size of organs, muscle properties and meat quality of pigs","volume":"107","author":"Ruusunen","year":"2007","journal-title":"Livest. Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1016\/j.anifeedsci.2015.06.003","article-title":"Trade-offs among growth performance, nutrient digestion and carcass traits when feeding low protein and\/or high neutral-detergent fiber diets to growing-finishing pigs","volume":"207","author":"Seradj","year":"2015","journal-title":"Anim. Feed Sci. Technol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"191","DOI":"10.22358\/jafs\/70362\/2005","article-title":"Physiological aspects of compensatory growth in pigs","volume":"14","author":"Skiba","year":"2005","journal-title":"J. Anim. Feed. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1079\/BJN19900011","article-title":"Utilization of ileal digestible amino acids by growing pigs: Effect of dietary lysine concentration on efficiency of lysine retention","volume":"64","author":"Batterham","year":"1990","journal-title":"Br. J. Nutr."},{"key":"ref_33","unstructured":"Greef, K.H.D. (1992). Prediction of Production: Nutrition Induced Tissue Partitioning in Growing Pigs, Wageningen University and Research."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1972","DOI":"10.2527\/jas.2015-0190","article-title":"Body composition, tissue deposition, and lysine utilization for protein deposition of barrows and gilts fed crystalline or protein-bound lysine","volume":"94","author":"Colina","year":"2016","journal-title":"J. Anim. Sci."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"348","DOI":"10.2527\/jas.2007-0009","article-title":"Investigations of energy metabolism in weanling barrows: The interaction of dietary energy concentration and daily feed (energy) intake","volume":"86","author":"Oresanya","year":"2008","journal-title":"J. Anim. Sci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"817","DOI":"10.2527\/1996.744817x","article-title":"Performance and body composition of finishing gilts (45 to 85 kilograms) as affected by energy intake and nutrition in earlier life: II. Protein and lipid accretion in body components","volume":"74","author":"Bikker","year":"1996","journal-title":"J. Anim. Sci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3251","DOI":"10.2527\/1991.6983251x","article-title":"Physical and chemical components of the empty body during compensatory growth in beef steers","volume":"69","author":"Carstens","year":"1991","journal-title":"J. Anim. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"3357","DOI":"10.2527\/1991.6983357x","article-title":"Growth, body composition, and visceral organ mass and metabolism in lambs during and after metabolizable protein or net energy restrictions","volume":"69","author":"Drouillard","year":"1991","journal-title":"J. Anim. Sci."},{"key":"ref_39","first-page":"556","article-title":"Effects of dietary energy and crude protein levels on growth performance, blood profiles, and nutrient digestibility in weaning pigs","volume":"32","author":"Fang","year":"2019","journal-title":"Asian-Australas. J. Anim. Sci."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Pedersen, C., and Boisen, S. (2001). Studies on the Response Time for Plasma Urea Nitrogen as a Rapid Measure for Dietary Protein Quality in Pigs. Acta Agric. Scand. Sect. A-Anim. Sci., 209\u2013216.","DOI":"10.1080\/09064700152717182"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"125","DOI":"10.2527\/2006.841125x","article-title":"Performance responses and indicators of gastrointestinal health in early-weaned pigs fed low-protein amino acid-supplemented diets","volume":"84","author":"Nyachoti","year":"2006","journal-title":"J. Anim. Sci."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1016\/j.aninu.2015.08.013","article-title":"Effects of protein sources and levels in antibiotic-free diets on diarrhea, intestinal morphology, and expression of tight junctions in weaned piglets","volume":"1","author":"Wu","year":"2015","journal-title":"Anim. Nutr."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/j.jnutbio.2010.11.007","article-title":"Comparison of serum metabolite compositions between obese and lean growing pigs using an NMR-based metabonomic approach","volume":"23","author":"He","year":"2012","journal-title":"J. Nutr. Biochem."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1203\/PDR.0b013e318189b0b4","article-title":"Impact of intrauterine growth retardation and early protein intake on growth, adipose tissue, and the insulin-like growth factor system in piglets","volume":"65","author":"Morise","year":"2009","journal-title":"Pediatr. Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1225","DOI":"10.1002\/oby.22531","article-title":"Protein Leverage: Theoretical Foundations and Ten Points of Clarification","volume":"27","author":"Raubenheimer","year":"2019","journal-title":"Obesity"},{"key":"ref_46","first-page":"20220212","article-title":"Protein appetite as an integrator in the obesity system: The protein leverage hypothesis","volume":"378","author":"Raubenheimer","year":"2023","journal-title":"Philos. Trans. R. Soc. Lond. Ser. B Biol. Sci."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1597","DOI":"10.1007\/s00726-011-0846-x","article-title":"Metabolism of select amino acids in bacteria from the pig small intestine","volume":"42","author":"Dai","year":"2012","journal-title":"Amino Acids"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"547","DOI":"10.1007\/s00726-006-0477-9","article-title":"Effects of amino acid-derived luminal metabolites on the colonic epithelium and physiopathological consequences","volume":"33","author":"Blachier","year":"2007","journal-title":"Amino Acids"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1002\/jsfa.10028","article-title":"Long-term effect of early antibiotic exposure on amino acid profiles and gene expression of transporters and receptors in the small intestinal mucosa of growing pigs with different dietary protein levels","volume":"100","author":"Yu","year":"2020","journal-title":"J. Sci. Food Agric."},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Jiang, Z., Mei, L., Li, Y., Guo, Y., Yang, B., Huang, Z., and Li, Y. (2024). Enzymatic Regulation of the Gut Microbiota: Mechanisms and Implications for Host Health. Biomolecules, 14.","DOI":"10.3390\/biom14121638"},{"key":"ref_51","first-page":"1504","article-title":"Effect of Two Macrocephala Flavored Powder supplementation on intestinal morphology and intestinal microbiota in weaning pigs","volume":"8","author":"Ye","year":"2015","journal-title":"Int. J. Clin. Exp. Med."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1038\/nri3608","article-title":"Intestinal epithelial cells: Regulators of barrier function and immune homeostasis","volume":"14","author":"Peterson","year":"2014","journal-title":"Nat. Rev. Immunol."},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Pearce, S.C., Nisley, M.J., Kerr, B.J., Sparks, C., and Gabler, N.K. (2024). Effects of dietary protein level on intestinal function and inflammation in nursery pigs. J. Anim. Sci., 102.","DOI":"10.1093\/jas\/skae077"},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Ijaz, M.U., Ahmed, M.I., Zou, X., Hussain, M., Zhang, M., Zhao, F., Xu, X., Zhou, G., and Li, C. (2018). Beef, Casein, and Soy Proteins Differentially Affect Lipid Metabolism, Triglycerides Accumulation and Gut Microbiota of High-Fat Diet-Fed C57BL\/6J Mice. Front. Microbiol., 9.","DOI":"10.3389\/fmicb.2018.02200"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1093\/jn\/nxaa331","article-title":"Supplemental Choline Modulates Growth Performance and Gut Inflammation by Altering the Gut Microbiota and Lipid Metabolism in Weaned Piglets","volume":"151","author":"Qiu","year":"2021","journal-title":"J. Nutr."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"1226","DOI":"10.4014\/jmb.2205.05041","article-title":"The Functional Roles of Lactobacillus acidophilus in Different Physiological and Pathological Processes","volume":"32","author":"Gao","year":"2022","journal-title":"J. Microbiol. Biotechnol."},{"key":"ref_57","doi-asserted-by":"crossref","unstructured":"Ortiz Sanju\u00e1n, J.M., Manzanilla, E.G., Cabrera-Rubio, R., Crispie, F., Cotter, P.D., Garrido, J.J., Ekhlas, D., O\u2019Neill, L., and Arg\u00fcello, H. (2024). Fine-tuning of post-weaning pig microbiome structure and functionality by in-feed zinc oxide and antibiotics use. Front. Cell. Infect. Microbiol., 14.","DOI":"10.3389\/fcimb.2024.1354449"}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/1\/24\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,23]],"date-time":"2025-12-23T05:15:12Z","timestamp":1766466912000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/1\/24"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,21]]},"references-count":57,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,1]]}},"alternative-id":["ani16010024"],"URL":"https:\/\/doi.org\/10.3390\/ani16010024","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,21]]}}}