{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T13:17:39Z","timestamp":1788182259775,"version":"build-2803163510"},"reference-count":0,"publisher":"Oxford University Press (OUP)","license":[{"start":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T00:00:00Z","timestamp":1788134400000},"content-version":"am","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>The indigestible core of forage fiber, quantified as indigestible neutral detergent fiber (iNDF, also denoted parametrically as \u03a9), critically influences ruminant intake, rumen fill, digestibility, and microbial substrate availability. This study estimated digestion kinetics and \u03a9 for 17 forage species (nine grasses and eight legumes) using long-term in vitro incubations and developed a scaling function for \u03a9 prediction from the Lignin(sa):aNDFom ratio. Multivariate analysis of chemical composition (DM, CP, CF, ash, aNDFom, Lignin(sa), and NFC) revealed distinct grass\u2013legume profiles, with grasses showing greater aNDFom (592\u2013763\u2009g\/kg DM) and lesser CP (76\u2013166\u2009g\/kg DM) than legumes, and lignin ratios ranging 40\u2013230\u2009g\/kg aNDFom. Incubations (up to 2,500\u2009h, with medium and inoculum renewal every 96\u2009h) produced biphasic degradation profiles that were fitted with nonlinear mixed models (EXP1, EXP2, GMM1, GMM2, and compartmental G\u03b7G1 and G\u03b7G1G1) in R (nlme). Information-theoretic criteria selected the heterogeneous two-pool compartmental model G6G1G1, which incorporated specimen-specific parameters, random block effects on the lag rate, power-of-the-mean variance, and a continuous autoregressive correlation structure. Fast pools ranged from 140\u2013571\u2009g\/kg, slow pools from 59\u2013379\u2009g\/kg, with corresponding degradation rates of 0.033\u20130.128\u2009h\u207b\u00b9 and 0.0026\u20130.0102\u2009h\u207b\u00b9. Parametric bootstrap (3,000 replicates) indicated that approximately 300\u2009h of incubation is sufficient to capture 95% of potentially digestible fiber, despite uncertainty in the slow pools. The scaling law \u03a9\u00a0=\u00a02.22Lignin(sa)\/aNDFom1.06 best predicted the indigestible residue, with diagnostics confirming model adequacy. Limitations include the modest number of forage specimens and residual uncertainty in the slow pools. This work integrates kinetic and chemical predictors to improve feed evaluation and ration formulation for ruminants.<\/jats:p>","DOI":"10.1093\/jas\/skag280","type":"journal-article","created":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T12:28:42Z","timestamp":1788179322000},"source":"Crossref","is-referenced-by-count":0,"title":["The indigestible core of forage fiber: estimation from long-term in vitro kinetics and prediction from lignin content"],"prefix":"10.1093","author":[{"given":"R S","family":"Gomes","sequence":"first","affiliation":[{"name":"Instituto Federal de Educa\u00e7\u00e3o , Ci\u00eancia e Tecnologia de Rond\u00f4nia (IFRO), campus Colorado do Oeste, Colorado do Oeste, RO 76993-000,","place":["Brazil"]},{"name":"Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) Graduate Program in Animal Science, , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R M S","family":"Santos","sequence":"additional","affiliation":[{"name":"Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) Graduate Program in Animal Science, , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J G","family":"Oliveira","sequence":"additional","affiliation":[{"name":"Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) Graduate Program in Animal Science, , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]},{"name":"Cargill Alimentos Ltda Cargill\/Nutron \u2013 Departamento de Bovinos de Corte. ., Av. Bailarina Selma Parada 505, Campinas, SP 13091-060,","place":["Brazil"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C S Eduardo","family":"J\u00fanior","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Zootecnia (LZO) , , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]},{"name":"Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) , , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S R","family":"Sim\u00e3o","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Zootecnia (LZO) , , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]},{"name":"Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) , , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M S","family":"Macedo","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Zootecnia (LZO) , , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]},{"name":"Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) , , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L O","family":"Tedeschi","sequence":"additional","affiliation":[{"name":"Texas A&M University Department of Animal Science, Kleberg Center, , College Station, TX 77843-2471,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R A M","family":"Vieira","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Zootecnia (LZO) , , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]},{"name":"Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) , , Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ 28013-602,","place":["Brazil"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,8,31]]},"container-title":["Journal of Animal Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/jas\/advance-article-pdf\/doi\/10.1093\/jas\/skag280\/70881653\/skag280.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jas\/advance-article-pdf\/doi\/10.1093\/jas\/skag280\/70881653\/skag280.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T12:28:42Z","timestamp":1788179322000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jas\/advance-article\/doi\/10.1093\/jas\/skag280\/8776627"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,31]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/jas\/skag280","relation":{},"ISSN":["0021-8812","1525-3163"],"issn-type":[{"value":"0021-8812","type":"print"},{"value":"1525-3163","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,31]]},"article-number":"skag280"}}