{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T05:31:33Z","timestamp":1767245493493,"version":"3.48.0"},"reference-count":49,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,12,30]],"date-time":"2025-12-30T00:00:00Z","timestamp":1767052800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior\u2014Brasil (CAPES)\u2014Finance Code 001"},{"DOI":"10.13039\/501100003593","name":"CNPq","doi-asserted-by":"crossref","award":["403469\/2013-9"],"award-info":[{"award-number":["403469\/2013-9"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>This study investigated how corn processing and protein degradability affect ruminal fermentation and feeding behavior in lactating Holstein cows. Twenty cows (averaging 162 \u00b1 70 days in lactation, 666 \u00b1 7 kg body weight, and 36.0 \u00b1 7.8 kg\/day milk yield) were assigned in a Latin square design with four 21-day periods and four treatments arranged in a 2 \u00d7 2 factorial: corn processing [ground corn (GC) vs. steam-flaked corn (SFC)] and crude protein (CP) degradability [high (HCP) vs. low (LCP)]. Ruminal samples were collected at eight time points (0, 2, 4, 6, 8, 10, 12 and 16 h) post-feeding to analyze pH, ammonia, and short-chain fatty acids, while feeding behavior was recorded visually every 5 min for 48 h. Corn processing and protein degradability interacted to influence rumen ammonia nitrogen (p = 0.057), urinary pH, (p = 0.041), nitrogen secretion and efficiency (p = 0.538), and feeding (min\/kg DM; p = 0.049) and rumination times (min\/kg DM, p = 0.001; min\/kg NDF, p = 0.001), reflecting changes in nitrogen metabolism. Steam-flaked corn decreased the acetate\/propionate ratio and enhanced propionate production, improving nitrogen retention and reducing urinary N losses, while highly degradable protein increased ruminal NH3-N and branched-chain VFA concentrations, particularly when combined with ground corn. Additionally, steam flaking reduced feed selectivity and increased rumination efficiency, supporting more effective use of nutrients for milk N secretion and overall nitrogen utilization efficiency in dairy cows. Overall, diets varying in corn processing and protein degradability altered ruminal metabolism, nutrient utilization, feeding behavior, and diet selectivity in lactating cows, highlighting their importance in optimizing dairy cow performance.<\/jats:p>","DOI":"10.3390\/ani16010107","type":"journal-article","created":{"date-parts":[[2025,12,31]],"date-time":"2025-12-31T13:30:52Z","timestamp":1767187852000},"page":"107","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effect of Corn Processing and Protein Degradability on Ruminal Metabolism and Feeding Behavior of Dairy Cows"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3010-6733","authenticated-orcid":false,"given":"Danielle de C\u00e1ssia Martins","family":"da Fonseca","sequence":"first","affiliation":[{"name":"Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of S\u00e3o Paulo, Pirassununga, S\u00e3o Paulo 13635-900, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3476-3458","authenticated-orcid":false,"given":"Cristian Marlon de Magalh\u00e3es Rodrigues","family":"Martins","sequence":"additional","affiliation":[{"name":"Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of S\u00e3o Paulo, Pirassununga, S\u00e3o Paulo 13635-900, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bruna Gomes","family":"Alves","sequence":"additional","affiliation":[{"name":"Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of S\u00e3o Paulo, Pirassununga, S\u00e3o Paulo 13635-900, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4205-1423","authenticated-orcid":false,"given":"Carlos Eduardo","family":"Fidelis","sequence":"additional","affiliation":[{"name":"Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of S\u00e3o Paulo, Pirassununga, S\u00e3o Paulo 13635-900, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4273-3494","authenticated-orcid":false,"given":"Marcos Veiga","family":"do Santos","sequence":"additional","affiliation":[{"name":"Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of S\u00e3o Paulo, Pirassununga, S\u00e3o Paulo 13635-900, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,30]]},"reference":[{"key":"ref_1","unstructured":"Medicine of Sciences Engineering (2021). 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