{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T17:15:13Z","timestamp":1792170913755,"version":"4.4.0"},"reference-count":34,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2025,10,16]],"date-time":"2025-10-16T00:00:00Z","timestamp":1760572800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"the National Research Foundation (NRF) of Korea","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"crossref"}]},{"name":"the government of the Republic of Korea","award":["RS-2023-00251171"],"award-info":[{"award-number":["RS-2023-00251171"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Veterinary Sciences"],"abstract":"<jats:p>Reproductive outcomes following synchronized ovulation protocol in beef cattle are influenced by multiple factors, making protocol selection based on farm-specific conditions essential. This retrospective study analyzed the relationship between pregnancy rates and associated factors under the CIDR (GnRH with CIDR insertion\u2013PGF2\u03b1 with CIDR removal\u2013GnRH), GPG (GnRH\u2013PGF2\u03b1\u2013GnRH), and GPPG (GnRH\u2013PGF2\u03b1\u2013PGF2\u03b1\u2013GnRH) protocols in Hanwoo cattle. The highest pregnancy rate was observed with the CIDR protocol (58.3%), whereas the GPG protocol yielded the lowest (47.5%). The CIDR protocol demonstrated superior suitability compared with the GPG protocol in first service (61.0% vs. 47.0%) and young breeding cattle (parity: 0\u20132; 61.6\u201370.0% vs. 47.5\u201348.6%). The dominant follicle size strongly associated with pregnancy success was 13\u201316 mm, and the CIDR protocol induced these follicles more frequently than the GPG protocol (50.2% vs. 35.5%). Although interpretive bias may exist from data collected from pregnant animals only, CIDR protocol significantly increased luteinizing hormone levels compared to GPG. The GPPG protocol produced outcomes that were improved relative to the GPG protocol and statistically comparable to the CIDR protocol. These findings addressed the study\u2019s objective, identifying optimal synchronized ovulation strategies and underscoring reproductive management importance for Korean Hanwoo operations.<\/jats:p>","DOI":"10.3390\/vetsci12101001","type":"journal-article","created":{"date-parts":[[2025,10,16]],"date-time":"2025-10-16T12:17:02Z","timestamp":1760617022000},"page":"1001","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Effects of Synchronized Ovulation Protocols on Reproductive Performance of Beef Cattle in Korea: A Retrospective Study of 755 Cases"],"prefix":"10.3390","volume":"12","author":[{"given":"Jong-Geol","family":"Ha","sequence":"first","affiliation":[{"name":"College of Veterinary Medicine, Kyungpook National University, Daegu 41566, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tae-Gyun","family":"Kim","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Kyungpook National University, Daegu 41566, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sung-Ho","family":"Kim","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Kyungpook National University, Daegu 41566, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sang-Yup","family":"Lee","sequence":"additional","affiliation":[{"name":"Bovivet, Gumi 39133, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saet-Byul","family":"Kim","sequence":"additional","affiliation":[{"name":"Bovivet, Gumi 39133, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Seung-Joon","family":"Kim","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Kyungpook National University, Daegu 41566, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1462-7798","authenticated-orcid":false,"given":"Won-Jae","family":"Lee","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Kyungpook National University, Daegu 41566, Republic of Korea"},{"name":"Institute for Veterinary Biomedical Science, Kyungpook National University, Daegu 41566, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"136","DOI":"10.5455\/vetworld.2011.136-141","article-title":"Synchronization of estrus in cattle: A review","volume":"4","author":"Islam","year":"2011","journal-title":"Vet. 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Animals, 11.","DOI":"10.3390\/ani11051236"}],"container-title":["Veterinary Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2306-7381\/12\/10\/1001\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,18]],"date-time":"2025-10-18T04:17:07Z","timestamp":1760761027000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2306-7381\/12\/10\/1001"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,16]]},"references-count":34,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2025,10]]}},"alternative-id":["vetsci12101001"],"URL":"https:\/\/doi.org\/10.3390\/vetsci12101001","relation":{},"ISSN":["2306-7381"],"issn-type":[{"value":"2306-7381","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,16]]}}}