{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,9]],"date-time":"2026-01-09T00:56:49Z","timestamp":1767920209998,"version":"3.49.0"},"reference-count":64,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,9,7]],"date-time":"2021-09-07T00:00:00Z","timestamp":1630972800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UIDB\/CVT\/00772\/2020"],"award-info":[{"award-number":["UIDB\/CVT\/00772\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"name":"AltBiotech RepGen Recursos gen\u00e9ticos animais","award":["ALT20-03-0246-FEDER-000021"],"award-info":[{"award-number":["ALT20-03-0246-FEDER-000021"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>This study aimed to evaluate and compare the effect of three semen extenders (S-EXT) on 22 spermatozoa (SPZ) parameters (subjective and computer-assisted sperm analysis evaluations), before and after semen cryopreservation throughout different months of the breeding season in the Portuguese Merino breed. According to the multivariable model, the SPZ viability (alive %), kinetics subjective individual motility, total motility, total progressive motility and its subpopulations, and beat cross frequency) were higher in the egg yolk-based S-EXT improved by Esta\u00e7\u00e3o Zoot\u00e9cnica National (Portugal) than in Ovixcell\u00ae or Andromed\u00ae extenders. All the differences were only observed in thawed semen, except for total motility and total progressive motility, in which Ovixcell\u00ae also showed the poorest results on fresh semen. An interaction effect between S-EXT and semen processing was observed on 72.3% (17\/22) of the evaluated parameters, evidencing a variable cryoprotective action between S-EXT. The SPZ viability was poorer in the onset of the breeding season (end of April\/early May) than in the previous middle breeding season (November\/early December), suggesting the influence of a short anoestrous season on ejaculate quality, even though the volume and SPZ concentration of the ejaculates remained stable throughout the experiment. Additionally, S-EXT x semen processing x month interaction effect on 59.1% (13\/22) of the evaluated parameters evidenced the importance of SPZ time collection in a natural environment to cryopreserve ram\u2019s semen. We concluded that, overall, the egg yolk-based S-EXT provided a greater value to the cryopreservation of Merino rams\u00b4 semen. Nevertheless, the causes of the interaction effect between S-EXT, semen processing and\/or month on several SPZ parameters should be addressed, including SPZ molecular research in new studies, in order to improve egg yolk-based as well as in egg yolk-free-based S-EXT.<\/jats:p>","DOI":"10.3390\/ani11092619","type":"journal-article","created":{"date-parts":[[2021,9,7]],"date-time":"2021-09-07T02:44:18Z","timestamp":1630982658000},"page":"2619","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Effects of Three Semen Extenders, Breeding Season Month and Freezing\u2013Thawing Cycle on Spermatozoa Preservation of Portuguese Merino Sheep"],"prefix":"10.3390","volume":"11","author":[{"given":"Margarida","family":"Fernandes","sequence":"first","affiliation":[{"name":"Department of Veterinary Sciences, Veterinary and Animal Research Centre (CECAV), School of Agricultural and Veterinary Sciences, University of Tr\u00e1s-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal"}]},{"given":"Pablo Rodr\u00edguez","family":"Hern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Department of Animal Production, International Agrifood Campus of Excellence (ceiA3), University of C\u00f3rdoba, Campus de Rabanales, 14014 C\u00f3rdoba, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4997-3933","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Sim\u00f5es","sequence":"additional","affiliation":[{"name":"Department of Veterinary Sciences, Veterinary and Animal Research Centre (CECAV), School of Agricultural and Veterinary Sciences, University of Tr\u00e1s-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8991-4009","authenticated-orcid":false,"given":"Jo\u00e3o Pedro","family":"Barbas","sequence":"additional","affiliation":[{"name":"Deparment of Biotecnology and Genetic Resources of Instituto Nacional de Investiga\u00e7\u00e3o Agr\u00e1ria e Veterin\u00e1ria, Quinta da Fonte Boa, 2005-048 Vale de Santar\u00e9m, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,9,7]]},"reference":[{"key":"ref_1","unstructured":"Evans, G., and Maxwell, W.M.C. 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