{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T03:20:46Z","timestamp":1773112846322,"version":"3.50.1"},"reference-count":58,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2023,9,4]],"date-time":"2023-09-04T00:00:00Z","timestamp":1693785600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"FONCYT\/MINCyT","award":["PICT-2021-I-A-00312"],"award-info":[{"award-number":["PICT-2021-I-A-00312"]}]},{"name":"FONCYT\/MINCyT","award":["29389"],"award-info":[{"award-number":["29389"]}]},{"name":"IPCVA","award":["PICT-2021-I-A-00312"],"award-info":[{"award-number":["PICT-2021-I-A-00312"]}]},{"name":"IPCVA","award":["29389"],"award-info":[{"award-number":["29389"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Fixed-timed artificial insemination (FTAI) protocols for beef cattle in South America are primarily based on estradiol esters and intravaginal progesterone-releasing devices (IVPD). The objective of this study was to determine the optimal gonadotropin-releasing hormone (GnRH)-based protocol as an alternative to the use of estrogen-based protocols in grazing Bos taurus suckling beef cows. All cows received an IVPD on the day of protocol initiation and prostaglandin F2\u03b1 (PG) plus equine chorionic gonadotropin (eCG) treatments at the time of IVPD removal. In Experiment 1, cows (n = 235) were randomly assigned to one of four treatments: (i) 7-day estradiol = 2 mg of estradiol benzoate (EB) at IVPD insertion on Day 9 and 1 mg of estradiol cypionate (ECP) at IVPD removal on Day 2; (ii) 7-day GnRH = 10 \u00b5g of GnRH at IVPD insertion on Day 10, IVPD removal on Day 3 and GnRH at FTAI; (iii) 7 &amp; 7 estradiol = PG at IVPD insertion on Day 16, EB on Day 9 and ECP at IVPD removal on Day 2; (iv) 7 &amp; 7 GnRH = PG at IVPD insertion on Day 17, GnRH on Day 10, IVPD removal on Day 3 and GnRH at FTAI. In Experiment 2, cows (n = 462) were randomly assigned to one of four treatments: (i) 6-day estradiol = EB at IVPD insertion on Day 9, IVPD removal on Day 3 and GnRH at FTAI; (ii) 7-day estradiol; (iii) 7-day GnRH; (iv) 7 &amp; 7 GnRH. In Experiment 1, plasma progesterone concentrations and percentage of cows with a corpus luteum (CL) at IVPD removal, and pregnancy per AI (P\/AI) were greater for cows subjected to GnRH-based protocols compared with cows subjected to estrogen-based protocols (p &lt; 0.01). In Experiment 2, cows subjected to the 7 &amp; 7 GnRH protocol had the greatest P\/AI (p &lt; 0.01). In summary, GnRH-based FTAI protocols resulted in similar or greater P\/AI compared to estrogen-based FTAI protocols in grazing postpartum Bos taurus suckled beef cows. The greatest P\/AI was attained with the 7 &amp; 7 GnRH protocol.<\/jats:p>","DOI":"10.3390\/ani13172803","type":"journal-article","created":{"date-parts":[[2023,9,4]],"date-time":"2023-09-04T02:26:12Z","timestamp":1693794372000},"page":"2803","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Comparison of Gonadotropin-Releasing Hormone versus Estrogen-Based Fixed-Time Artificial Insemination Protocols in Grazing Bos taurus Suckled Beef Cows"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2368-7039","authenticated-orcid":false,"given":"Luis B.","family":"Ferr\u00e9","sequence":"first","affiliation":[{"name":"National Institute of Agricultural Technology (INTA), Chacra Experimental Integrada Barrow (MDA-INTA), Tres Arroyos B7500, Buenos Aires, Argentina"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Julian","family":"Jaeschke","sequence":"additional","affiliation":[{"name":"Departamento T\u00e9cnico de Biog\u00e9nesis Bag\u00f3 S.A., Garin B1619, Buenos Aires, Argentina"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Juliana","family":"Gatti","sequence":"additional","affiliation":[{"name":"Departamento T\u00e9cnico de Biog\u00e9nesis Bag\u00f3 S.A., Garin B1619, Buenos Aires, Argentina"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gerardo","family":"Balad\u00f3n","sequence":"additional","affiliation":[{"name":"Departamento T\u00e9cnico de Biog\u00e9nesis Bag\u00f3 S.A., Garin B1619, Buenos Aires, Argentina"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ezequiel","family":"Bellocq","sequence":"additional","affiliation":[{"name":"Servicio T\u00e9cnico de Biog\u00e9nesis Bag\u00f3 S.A., Garin B1619, Buenos Aires, Argentina"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gustavo","family":"Fern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Private Veterinary Practice, Indio Rico B7501, Buenos Aires, Argentina"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1182-4454","authenticated-orcid":false,"given":"Ramiro","family":"Rearte","sequence":"additional","affiliation":[{"name":"Instituto de Investigaciones en Reproducci\u00f3n Animal (INIRA), Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, La Plata B1900, Buenos Aires, Argentina"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6162-1578","authenticated-orcid":false,"given":"Michael E.","family":"Kjelland","sequence":"additional","affiliation":[{"name":"Mayville State University, Mayville, ND 58257, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7793-6515","authenticated-orcid":false,"given":"Marcos G.","family":"Colazo","sequence":"additional","affiliation":[{"name":"Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8804-4694","authenticated-orcid":false,"given":"Jordan M.","family":"Thomas","sequence":"additional","affiliation":[{"name":"Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,9,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1016\/j.anireprosci.2004.04.025","article-title":"The use of hormonal treatments to improve reproductive performance of anestrous beef cattle in tropical climates","volume":"82\u201383","author":"Baruselli","year":"2004","journal-title":"Anim. Reprod. Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.anireprosci.2008.08.009","article-title":"Oestrous synchronisation in cattle\u2014Current options following the EU regulations restricting use of oestrogenic compounds in food\u2013producing animals: A review","volume":"109","author":"Lane","year":"2008","journal-title":"Anim. Reprod. Sci."},{"key":"ref_3","first-page":"772","article-title":"A Review of Current Timed\u2013AI (TAI) Programs for Beef and Dairy Cattle","volume":"55","author":"Colazo","year":"2014","journal-title":"Can. Vet. J."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"388","DOI":"10.1016\/j.theriogenology.2016.04.053","article-title":"Alternative programs for synchronizing and resynchronizing ovulation in beef cattle","volume":"86","author":"Baruselli","year":"2016","journal-title":"Theriogenology"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"915","DOI":"10.1016\/0093-691X(95)00279-H","article-title":"Synchronization of Ovulation in Dairy Cows Using PGF2\u03b1 and GnRH","volume":"44","author":"Pursley","year":"1995","journal-title":"Theriogenology"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.15232\/S1080-7446(15)31653-3","article-title":"Ovarian and Estrous Response of Suckled Beef Cows to the Select Synch Estrous Synchronization Protocol","volume":"16","author":"Geary","year":"2000","journal-title":"Prof. Anim. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/j.domaniend.2006.11.004","article-title":"Effects of plasma progesterone concentrations on LH release and ovulation in beef cattle given GnRH","volume":"34","author":"Colazo","year":"2008","journal-title":"Domest. Anim. Endocrinol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"698","DOI":"10.1016\/j.theriogenology.2008.09.045","article-title":"Effects of progesterone presynchronization and eCG on pregnancy rates to GnRH\u2013based, timed\u2013AI in beef cattle","volume":"71","author":"Small","year":"2009","journal-title":"Theriogenology"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/S0378-4320(99)00057-3","article-title":"Effect of LH or GnRH on the dominant follicle of the first follicular wave in beef heifers","volume":"57","author":"Martinez","year":"1999","journal-title":"Anim. Reprod. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1016\/j.theriogenology.2020.08.018","article-title":"Treatment with prostaglandin F2\u03b1 and an intravaginal progesterone insert promotes follicular maturity in advance of gonadotropin\u2013releasing hormone among postpartum beef cows","volume":"157","author":"Bonacker","year":"2020","journal-title":"Theriogenology"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"106892","DOI":"10.1016\/j.anireprosci.2021.106892","article-title":"Evaluation of the 7 & 7 Synch and 7\u2013day CO\u2013Synch + CIDR treatment regimens for control of the estrous cycle among beef cows prior to fixed\u2013time artificial insemination with conventional or sex\u2013sorted semen","volume":"235","author":"Andersen","year":"2021","journal-title":"Anim. Reprod. Sci."},{"key":"ref_12","first-page":"1428","article-title":"Prediction of Postpartum Beef Cow Body Composition Using Weight to Height Ratio and Visual Body Condition Score","volume":"68","author":"Houghton","year":"1990","journal-title":"J. Anim. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1343","DOI":"10.1016\/j.theriogenology.2008.12.026","article-title":"Compilation of classical and contemporary terminology used to describe morphological aspects of ovarian dynamics in cattle","volume":"71","author":"Peter","year":"2009","journal-title":"Theriogenology"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"403","DOI":"10.1017\/S002202991400034X","article-title":"Continuous milking of dairy cows disrupts timing of peak IgG concentration appearance in mammary secretions","volume":"81","author":"Baumrucker","year":"2014","journal-title":"J. Dairy Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1136\/vr.114.25.605","article-title":"Tail Painting Technique as an Aid to Oestrus Detection in Cattle","volume":"114","author":"Kerr","year":"1984","journal-title":"Vet. Rec."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"402","DOI":"10.21451\/1984-3143-AR2019-0041","article-title":"Pre\u2013TAI protocol strategies to increase reproductive efficiency in beef and dairy cows","volume":"16","author":"Sales","year":"2019","journal-title":"Anim. Reprod."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1016\/j.theriogenology.2020.09.033","article-title":"Comparison of the 7 & 7 Synch protocol and the 7\u2013day CO\u2013Synch + CIDR protocol among recipient beef cows in an embryo transfer program","volume":"158","author":"Bonacker","year":"2020","journal-title":"Theriogenology"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1093\/jas\/skx043","article-title":"Impacts of estrus expression and intensity during a timed\u2013AI protocol on variables associated with fertility and pregnancy success in Bos indicus\u2013influenced beef cows","volume":"96","author":"Rodrigues","year":"2018","journal-title":"J. Anim. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2569","DOI":"10.1017\/S1751731119000636","article-title":"Estrous expression during a fixed\u2013time artificial insemination protocol enhances development and interferon\u2013tau messenger RNA expression in conceptuses from Bos indicus beef cows","volume":"13","author":"Cooke","year":"2019","journal-title":"Animal"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2837","DOI":"10.3168\/jds.2012-5840","article-title":"Timing of prostaglandin F2\u03b1 treatment in an estrogen\u2013based protocol for timed artificial insemination or timed embryo transfer in lactating dairy cows","volume":"96","author":"Pereira","year":"2013","journal-title":"J. Dairy Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1016\/j.domaniend.2007.09.003","article-title":"Effect of preovulatory concentrations of estradiol and initiation of standing estrus on uterine pH in beef cows","volume":"34","author":"Perry","year":"2008","journal-title":"Domest. Anim. Endocrinol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2645","DOI":"10.3168\/jds.S0022-0302(83)82138-9","article-title":"Sperm survival and transport in the female reproductive tract","volume":"66","author":"Hawk","year":"1983","journal-title":"J. Dairy Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1530\/rep.0.1230355","article-title":"Characterization and Biological Roles of Oviduct\u2013Specific, Oestrogen\u2013Dependent Glycoprotein","volume":"123","author":"Buhi","year":"2002","journal-title":"Reproduction"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"S138","DOI":"10.1016\/j.theriogenology.2007.03.018","article-title":"Role of the Oviduct in Sperm Capacitation","volume":"68","year":"2007","journal-title":"Theriogenology"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1016\/S0093-691X(01)00565-9","article-title":"Reduction in size of the ovulatory follicle reduces subsequent luteal size and pregnancy rate","volume":"56","author":"Vasconcelos","year":"2001","journal-title":"Theriogenology"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"455","DOI":"10.1016\/j.theriogenology.2011.02.022","article-title":"Importance of estrus on pregnancy per insemination in suckled Bos indicus cows submitted to estradiol\/progesterone\u2013based timed insemination protocols","volume":"76","author":"Santos","year":"2011","journal-title":"Theriogenology"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"335","DOI":"10.4141\/A00-077","article-title":"The effects of gonadotrophin releasing hormone in prostaglandin F2\u03b1\u2013based timed insemination programs for beef cattle","volume":"81","author":"Small","year":"2001","journal-title":"Can. J. Anim. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1049","DOI":"10.1016\/S0093-691X(01)00682-3","article-title":"The use of progestins in regimens for fixed\u2013time artificial insemination in beef cattle","volume":"57","author":"Kastelic","year":"2002","journal-title":"Theriogenology"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1016\/S0093-691X(01)00580-5","article-title":"Attenuation of premature estrous behavior in postpartum beef cows synchronized to estrus using GnRH and PGF2\u03b1","volume":"56","author":"DeJarnette","year":"2001","journal-title":"Theriogenology"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"5268","DOI":"10.1073\/pnas.0501700102","article-title":"Relationship between follicle size at insemination and pregnancy success","volume":"102","author":"Perry","year":"2005","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1530\/jrf.0.1020123","article-title":"Association between the duration of dominance of the ovulatory follicle and pregnancy rate in beef heifers","volume":"102","author":"Mihm","year":"1994","journal-title":"J. Reprod. Fertil."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1071\/RDv16n1Ab14","article-title":"Ovarian follicular dynamics in cows treated with a CIDR, estradiol and progesterone late in the estrous cycle","volume":"16","author":"Kastelic","year":"2004","journal-title":"Reprod. Fertil. Dev."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"3014","DOI":"10.2527\/jas.2012-5887","article-title":"Influence of follicular characteristics at ovulation on early embryonic survival","volume":"91","author":"Geary","year":"2013","journal-title":"J. Anim. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/j.anireprosci.2016.01.013","article-title":"Expression of estrus before fixed\u2013time AI affects conception rates and factors that impact expression of estrus and the repeatability of expression of estrus in sequential breeding seasons","volume":"166","author":"Richardson","year":"2016","journal-title":"Anim. Reprod. Sci."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.domaniend.2014.02.001","article-title":"Relationship of follicle size and concentrations of estradiol among cows exhibiting or not exhibiting estrus during a fixed\u2013time AI protocol","volume":"48","author":"Perry","year":"2014","journal-title":"Domest. Anim. Endocrinol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1111\/j.1439-0531.2012.02067.x","article-title":"Manipulation of Follicle Development to Ensure Optimal Oocyte Quality and Conception Rates in Cattle","volume":"47","author":"Baruselli","year":"2012","journal-title":"Reprod. Dom. Anim."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"103886","DOI":"10.1016\/j.livsci.2019.103886","article-title":"Effect of estradiol cypionate on estrus expression and pregnancy in timed artificially inseminated beef cows","volume":"231","author":"Pfeifer","year":"2020","journal-title":"Livest. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"4189","DOI":"10.2527\/jas.2014-7827","article-title":"Delayed insemination of non\u2013estrous heifers and cows when using conventional semen in timed artificial insemination","volume":"92","author":"Thomas","year":"2014","journal-title":"J. Anim. Sci."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1016\/j.theriogenology.2017.04.046","article-title":"Split\u2013time artificial insemination in beef cattle: III. Comparing fixed\u2013time artificial insemination to split\u2013time artificial insemination with delayed administration of GnRH in postpartum cows","volume":"99","author":"Bishop","year":"2017","journal-title":"Theriogenology"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1102","DOI":"10.1016\/j.theriogenology.2016.03.043","article-title":"Split\u2013time artificial insemination in beef cattle: I\u2013Using estrous response to determine the optimal time(s) at which to administer GnRH in beef heifers and postpartum cows","volume":"86","author":"Bishop","year":"2016","journal-title":"Theriogenology"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"106954","DOI":"10.1016\/j.anireprosci.2022.106954","article-title":"Success of artificial insemination based on expression of estrus and the addition of GnRH to an estradiol\/progesterone\u2013based protocol on pregnancy rates in lactating dairy cows","volume":"238","author":"Tschopp","year":"2022","journal-title":"Anim. Reprod. Sci."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1016\/j.theriogenology.2020.12.014","article-title":"Effect of expression of estrus and treatment with GnRH on pregnancies per AI in beef cattle synchronized with an estradiol\/progesterone\u2013based protocol","volume":"161","author":"Cuervo","year":"2021","journal-title":"Theriogenology"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"151","DOI":"10.2527\/jas.2006-335","article-title":"Ovarian, hormonal, and reproductive events associated with synchronization of ovulation and timed appointment breeding of Bos indicus\u2013influenced cattle using intravaginal progesterone, gonadotropin\u2013releasing hormone, and prostaglandin F2\u03b1","volume":"85","author":"Saldarriaga","year":"2007","journal-title":"J. Anim. Sci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1016\/j.theriogenology.2019.09.047","article-title":"Pregnancy rates to fixed\u2013time AI in Bos indicus\u2013influenced beef cows using PGF2\u03b1 with (Bee Synch I) or without (Bee Synch II) GnRH at the onset of the 5\u2013day CO\u2013Synch + CIDR protocol","volume":"142","author":"Williams","year":"2020","journal-title":"Theriogenology"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1663","DOI":"10.2527\/jas.2009-2480","article-title":"Presynchronization with gonadotropin\u2013releasing hormone increases the proportion of Bos indicus\u2013influenced females ovulating at initiation of synchronization but fails to improve synchronized new follicular wave emergence or fixed\u2013time artificial inseminat","volume":"88","author":"Zuluaga","year":"2010","journal-title":"J. Anim. Sci."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1016\/j.theriogenology.2009.02.010","article-title":"Fixed\u2013time artificial insemination with estradiol and progesterone for Bos indicus cows I: Basis for development of protocols","volume":"72","author":"Meneghetti","year":"2009","journal-title":"Theriogenology"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.theriogenology.2020.01.033","article-title":"Progesterone\u2013based timed AI protocols for Bos indicus cattle II: Reproductive outcomes of either EB or GnRH\u2013type protocol, using or not GnRH at AI","volume":"145","author":"Madureira","year":"2020","journal-title":"Theriogenology"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"124","DOI":"10.15232\/S1080-7446(15)31391-7","article-title":"Incidence of Postpartum Anestrus in Suckled Beef Cattle: Treatments to Induce Estrus, Ovulation, and Conception","volume":"19","author":"Stevenson","year":"2003","journal-title":"Prof. Anim. Sci."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"s45","DOI":"10.1017\/S175173111800054X","article-title":"Review: Using artificial insemination v. natural service in beef herds","volume":"12","author":"Baruselli","year":"2018","journal-title":"Animal"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"2253","DOI":"10.2527\/2001.7992253x","article-title":"Inclusion of an intravaginal progesterone insert plus GnRH and prostaglandin F2\u03b1 for ovulation control in postpartum suckled beef cows","volume":"79","author":"Lamb","year":"2001","journal-title":"J. Anim. Sci."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0093-691X(00)00322-8","article-title":"Induction of ovulation in postpartum suckled beef cows: A review","volume":"54","author":"Yavas","year":"2000","journal-title":"Theriogenology"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"2300","DOI":"10.2527\/jas.2009-2531","article-title":"Factors affecting preovulatory follicle diameter and ovulation rate after gonadotropin\u2013releasing hormone in postpartum beef cows. Part I: Cycling cows","volume":"88","author":"Atkins","year":"2010","journal-title":"J. Anim. Sci."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"238","DOI":"10.17555\/jvc.2023.40.3.238","article-title":"Effects of Ovarian Status at the Time of Initiation of the Modified Double\u2013Ovsynch Program on the Reproductive Performance in Dairy Cows","volume":"40","author":"Jeong","year":"2023","journal-title":"J. Vet. Clin."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"362","DOI":"10.1095\/biolreprod29.2.362","article-title":"Coincident Secretion of Follicle\u2013Stimulating Hormone and Luteinizing Hormone in Early Postpartum Beef Cows: Effects of Suckling and Low\u2013Level Increases of Systemic Progesterone","volume":"29","author":"Williams","year":"1983","journal-title":"Biol. Reprod."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1099","DOI":"10.2527\/jas1987.6441099x","article-title":"Effects of Norgestomet on Follicular Development in Postpartum Beef Cows","volume":"64","author":"Lewis","year":"1987","journal-title":"J. Anim. Sci."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1111\/j.1439-0531.2008.01210.x","article-title":"Resumption of Ovarian Cyclicity in Post\u2013partum Beef and Dairy Cows","volume":"43","author":"Crowe","year":"2008","journal-title":"Reprod. Domest. Anim."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1017\/S175173111400086X","article-title":"Optimising reproductive performance of beef cows and replacement heifers","volume":"8","author":"Diskin","year":"2014","journal-title":"Animal"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1016\/j.theriogenology.2018.11.010","article-title":"Influence of nutrition, body condition, and metabolic status on reproduction in female beef cattle: A review","volume":"125","author":"Baruselli","year":"2019","journal-title":"Theriogenology"}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/13\/17\/2803\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:45:56Z","timestamp":1760129156000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/13\/17\/2803"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,9,4]]},"references-count":58,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2023,9]]}},"alternative-id":["ani13172803"],"URL":"https:\/\/doi.org\/10.3390\/ani13172803","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,9,4]]}}}