{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T20:09:56Z","timestamp":1791230996728,"version":"4.1.0"},"reference-count":34,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2024,8,28]],"date-time":"2024-08-28T00:00:00Z","timestamp":1724803200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"The National Research Council of Thailand (NRCT)","award":["N42A660892"],"award-info":[{"award-number":["N42A660892"]}]},{"name":"MSD Animal Health. P. Taechamaeteekul received PhD Scholarships from the Second Century Fund (C2F), Chulalongkorn University","award":["N42A660892"],"award-info":[{"award-number":["N42A660892"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>The use of exogenous hormones has long been of interest for improving reproductive performance in swine production. Enhancing litter size directly impacts the economic efficiency of pig production. Various strategies, including nutritional, genetic, and hormonal approaches, have been explored with varying degrees of success. Administering a gonadotropin-releasing hormone (GnRH) agonist, such as buserelin, at the onset of estrus can induce ovulation and reduce the variation in ovulation timing among sows. This study assessed the impact of GnRH agonist supplementation in boar semen doses on the litter size of inseminated gilts. The research was conducted on a commercial swine herd in northern Thailand. A total of 231 Landrace \u00d7 Yorkshire crossbred gilts, aged 224.5 \u00b1 16.2 days at the onset of estrus synchronization, participated in the experiment. The gilts\u2019 estrus was synchronized with oral altrenogest supplementation at a dosage of 20 mg\/day for 18 days. After exhibiting standing estrus, the gilts were randomly divided into three groups. Control group: gilts were inseminated at 0 and 12 h post standing estrus onset with a conventional semen dose (n = 94). Treatment 1: similar to the control group, but with an added 5 \u00b5g (1.25 mL) of buserelin acetate to the boar semen dose during the first insemination (n = 71). Treatment 2: similar to the control group, but with 10 \u00b5g (2.5 mL) of buserelin acetate added to the boar semen dose during the first insemination (n = 66). All gilts were inseminated twice during their standing estrus using the intrauterine artificial insemination method. Each semen dose contained 3.0 \u00d7 109 motile sperm in 80 mL. The farrowing rate averaged 78.8% and did not significantly differ between the groups (p = 0.141). The total number of piglets born per litter in the treatment 2 group was greater than in the control group (14.0 \u00b1 0.3 vs. 13.2 \u00b1 0.3, respectively, p = 0.049), but was not significantly different from the treatment 1 group (13.3 \u00b1 0.3, p = 0.154). Similarly, the number of live-born piglets in the treatment 2 group was greater than in the control and treatment 1 groups (13.2 \u00b1 0.4 vs. 12.3 \u00b1 0.3 and 12.0 \u00b1 0.4, respectively, p &lt; 0.05). Moreover, the live-born piglets\u2019 litter birth weight in the treatment 2 group was greater than in the control group (17.0 \u00b1 0.4 vs. 15.6 \u00b1 0.3 kg, respectively, p = 0.008) and the treatment 1 group (15.7 \u00b1 0.4 kg, p = 0.025). In conclusion, adding a GnRH agonist to boar semen appears to enhance the litter size of gilts. Further research should focus on understanding the underlying mechanisms and determining the optimal dose and timing for GnRH agonist supplementation.<\/jats:p>","DOI":"10.3390\/ani14172501","type":"journal-article","created":{"date-parts":[[2024,8,28]],"date-time":"2024-08-28T07:52:08Z","timestamp":1724831528000},"page":"2501","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Buserelin Acetate Added to Boar Semen Enhances Litter Size in Gilts in Tropical Environments"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9856-1847","authenticated-orcid":false,"given":"Preechaphon","family":"Taechamaeteekul","sequence":"first","affiliation":[{"name":"Centre of Excellence in Swine Reproduction, Department of Obstetrics, Gynaecology and Reproduction, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chatchapong","family":"Jaijarim","sequence":"additional","affiliation":[{"name":"Charoen Pokphand Foods Public Company Limited, Bangkok 10120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chairach","family":"Audban","sequence":"additional","affiliation":[{"name":"Charoen Pokphand Foods Public Company Limited, Bangkok 10120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kridtasak","family":"Sang-Gassanee","sequence":"additional","affiliation":[{"name":"Intervet (Thailand) Ltd., South Sathorn Rd., Yannawa, Sathorn, Bangkok 10120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pongsak","family":"Numsri","sequence":"additional","affiliation":[{"name":"Intervet (Thailand) Ltd., South Sathorn Rd., Yannawa, Sathorn, Bangkok 10120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1524-9699","authenticated-orcid":false,"given":"Hongyao","family":"Lin","sequence":"additional","affiliation":[{"name":"Merck Animal Health, 2 Giralda Farms, Madison, NJ 07940, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miquel","family":"Collell","sequence":"additional","affiliation":[{"name":"Merck Animal Health, 2 Giralda Farms, Madison, NJ 07940, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7000-4371","authenticated-orcid":false,"given":"Padet","family":"Tummaruk","sequence":"additional","affiliation":[{"name":"Centre of Excellence in Swine Reproduction, Department of Obstetrics, Gynaecology and Reproduction, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/j.theriogenology.2015.07.009","article-title":"Artificial insemination in pigs today","volume":"85","author":"Knox","year":"2016","journal-title":"Theriogenology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1756","DOI":"10.1111\/rda.13836","article-title":"Factors influencing pre-ovulatory follicle diameter and weaning-to-ovulation interval in spontaneously ovulating sows in tropical environment","volume":"55","author":"Pearodwong","year":"2020","journal-title":"Reprod. Domest. Anim."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1075","DOI":"10.1016\/j.theriogenology.2008.06.027","article-title":"Synchronization of ovulation in cyclic gilts with porcine luteinizing hormone (pLH) and its effects on reproductive function","volume":"70","author":"Degenstein","year":"2008","journal-title":"Theriogenology"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1016\/0093-691X(92)90028-P","article-title":"The duration of ovulation in pigs, studied by transrectal ultrasonography, is not related to early embryonic diversity","volume":"38","author":"Soede","year":"1992","journal-title":"Theriogenology"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1571","DOI":"10.1016\/S0093-691X(97)00162-3","article-title":"The influence of time of insemination relative to time of ovulation on farrowing frequency and litter size in sows, as investigated by ultrasonography","volume":"47","author":"Nissen","year":"1997","journal-title":"Theriogenology"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1046\/j.1439-0531.2003.00434.x","article-title":"The effect of post-ovulatory artificial insemination on sow reproductive performance","volume":"38","author":"Castagna","year":"2003","journal-title":"Reprod. Domest. Anim."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"797","DOI":"10.1111\/j.1439-0442.1989.tb00794.x","article-title":"Replenishment of AI-doses with oestrogens in physiological amounts: Effect on sow prolificacy in a field trial","volume":"36","author":"Claus","year":"1989","journal-title":"J. Vet. Med. A"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1053\/tvjl.1999.0428","article-title":"Intrauterine infusion of PGF2\u03b1at insemination enhances reproductive performance of sows during the low fertility season","volume":"159","author":"Pena","year":"2000","journal-title":"Vet. J."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"780","DOI":"10.1016\/j.theriogenology.2014.01.003","article-title":"The use of oxytocin in liquid semen doses to reduce seasonal fluctuations in the reproductive performance of sows and improve litter parameters\u2014A 2-year study","volume":"81","author":"Knecht","year":"2014","journal-title":"Theriogenology"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"849","DOI":"10.1016\/S0093-691X(02)01157-3","article-title":"Effects of different sexual stimuli on oxytocin release, uterine activity and receptive behavior in estrous sows","volume":"59","author":"Langendijk","year":"2003","journal-title":"Theriogenology"},{"key":"ref_11","first-page":"117","article-title":"Physiological role of seminal components in the reproductive tract of the female pig","volume":"40","author":"Claus","year":"1990","journal-title":"J. Reprod. Fertil. Suppl."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1016\/j.theriogenology.2017.01.033","article-title":"Effect of numbers of sperm and timing of a single, post-cervical insemination on the fertility of weaned sows treated with OvuGel\u00ae","volume":"92","author":"Knox","year":"2017","journal-title":"Theriogenology"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"391","DOI":"10.1016\/j.theriogenology.2013.05.002","article-title":"Induction of an LH surge and ovulation by buserelin (as Receptal) allows breeding of weaned sows with a single fixed-time insemination","volume":"80","author":"Driancourt","year":"2013","journal-title":"Theriogenology"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.theriogenology.2019.09.032","article-title":"Reproductive performance of weaned sows after single fixed-time artificial insemination under a tropical climate: Influences of season and insemination technique","volume":"142","author":"Pearodwong","year":"2020","journal-title":"Theriogenology"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.theriogenology.2022.08.026","article-title":"Gilt reproductive performance in a tropical environment after oestrus synchronization and fixed-time artificial insemination","volume":"192","author":"Tummaruk","year":"2022","journal-title":"Theriogenology"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2186","DOI":"10.3168\/jds.S0022-0302(86)80652-X","article-title":"Controlling first service and calving interval by prostaglandin F2\u03b1, gonadotropin-releasing hormone, and timed insemination","volume":"69","author":"Lucy","year":"1986","journal-title":"J. Dairy Sci."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Uddin, A.M., Petrovski, K.R., Song, Y., Garg, S., and Kirkwood, R.N. (2023). Application of exogenous GnRH in food animal production. Animals, 13.","DOI":"10.3390\/ani13121891"},{"key":"ref_18","first-page":"362","article-title":"Induction and synchronization of ovulation in sows using a Gonadotropin-releasing Hormone Analog (Lecirelin)","volume":"7","author":"Fries","year":"2018","journal-title":"Anim. Reprod."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1016\/j.anireprosci.2010.04.003","article-title":"Endocrine, ovulatory and reproductive characteristics of sows treated with an intravaginal GnRH agonist","volume":"120","author":"Stewart","year":"2010","journal-title":"Anim. Reprod. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1007\/s11250-011-9920-3","article-title":"Effect of the administration of GnRH or hCG on time of ovulation and the onset of estrus-to-ovulation interval in sows in Thailand","volume":"44","author":"Wongkaweewit","year":"2010","journal-title":"Trop. Anim. Health Prod."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Su\u00e1rez-Usbeck, A., Mitjana, O., Tejedor, M.T., Bonastre, C., Sistac, J., Ubiergo, A., and Falceto, M.V. (2021). Single fixed-time post-cervical insemination in gilts with buserelin. Animals, 11.","DOI":"10.3390\/ani11061567"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"308","DOI":"10.1016\/j.theriogenology.2010.09.001","article-title":"Synchronization of ovulation and fertility in weaned sows treated with intravaginal triptorelin is influenced by timing of administration and follicle size","volume":"75","author":"Knox","year":"2011","journal-title":"Theriogenology"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"571","DOI":"10.1111\/rda.14326","article-title":"GnRH agonists: Updating fixed-time artificial insemination protocols in sows","volume":"58","author":"Falceto","year":"2023","journal-title":"Reprod. Domest. Anim."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1031","DOI":"10.1016\/j.theriogenology.2007.08.004","article-title":"Ovulation induced by mucosa vaginal absorption of buserelin and triptorelin in rabbit","volume":"68","author":"Lavara","year":"2007","journal-title":"Theriogenology"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Manjar\u00edn, R., Kirkwood, R.N., Ngula, J., Martinez-Pastor, F., Alegre, B., and Dom\u00ednguez, J.C. (2019). Effect of oxytocin, cloprostenol or buserelin in semen doses on sow fertility. Animals, 9.","DOI":"10.3390\/ani9100746"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"533","DOI":"10.1002\/mrd.23661","article-title":"Managing prolific sows in tropical environments","volume":"90","author":"Tummaruk","year":"2023","journal-title":"Mol. Reprod. Dev."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1016\/j.prevetmed.2010.06.003","article-title":"Influence of repeat-service and weaning-to-first-service interval on farrowing proportion of gilts and sows","volume":"96","author":"Tummaruk","year":"2010","journal-title":"Prev. Vet. Med."},{"key":"ref_28","first-page":"495","article-title":"Intravaginal GnRH agonist gel advances time of ovulation and facilitates timed AI in weaned sows","volume":"11","author":"Knox","year":"2003","journal-title":"Am. Ass. Swine Vet."},{"key":"ref_29","unstructured":"Taibl, J.N., Breen, S.M., Webel, S.K., Swanson, M.E., and Knox, R.V. (2009). Effect of synchronizing ovulation in weaned sows using OvuGel with single fixed time AI on pregnancy rate and litter size. Control of Pig Reproduction VIII: Proceedings of the Eighth International Conference on Pig Reproduction, Alberta, Canada, June 2009, Society for Reproduction and Fertility; Nottingham University Press."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1111\/j.1439-0531.2011.01828.x","article-title":"Approaches towards efficient use of boar semen in the pig industry","volume":"46","author":"Roca","year":"2011","journal-title":"Reprod. Domest. Anim."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Kong, J., Su, F., Liu, Y., Yang, Y., Cao, Y., Qiu, J., Wang, Y., Zhang, L., Wang, J., and Cao, X. (2022). The pharmacokinetics of buserelin after intramuscular administration in pigs and cows. BMC Vet. Res., 18.","DOI":"10.1186\/s12917-022-03237-0"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1016\/j.anireprosci.2014.08.009","article-title":"Induction of ovulation in rabbits by adding Lecirelin to the seminal dose: In vitro and in vivo effects of different excipients","volume":"150","author":"Cardinali","year":"2014","journal-title":"Anim. Reprod. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"529","DOI":"10.1095\/biolreprod.102.013052","article-title":"Decrease in order of human sperm lipids during capacitation","volume":"69","author":"Cross","year":"2003","journal-title":"Biol. Reprod."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1111\/j.1439-0531.2008.01095.x","article-title":"Reproductive performance of rabbit does artificially inseminated via intravaginal administration of [des-Gly 10, d-Ala6]-LHRH ethylamide as ovulation inductor","volume":"44","author":"Quintela","year":"2009","journal-title":"Reprod. Domest. Anim."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/17\/2501\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:44:19Z","timestamp":1760111059000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/17\/2501"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,28]]},"references-count":34,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2024,9]]}},"alternative-id":["ani14172501"],"URL":"https:\/\/doi.org\/10.3390\/ani14172501","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,8,28]]}}}