| Strategies to improve pregnancy per insemination using sex-sorted semen in dairy heifers detected in estrus. | |
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MedLine Citation:
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PMID: 20833421 Owner: NLM Status: In-Process |
Abstract/OtherAbstract:
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The objective was to improve pregnancy per artificial insemination (P/AI; 35-42 d after AI) in virgin Jersey heifers bred by AI of sex-sorted semen after being detected in estrus. Giving 100 μg of GnRH at first detection of estrus, with AI 12 h later, did not affect P/AI in Experiment I [GnRH = 47.2% (100/212) vs. No GnRH = 51.7% (104/201); P = 0.38] or Experiment II [GnRH = 53.1% (137/258) vs. No GnRH = 48.6% (122/251); P = 0.43]. In these two experiments, estrus detection was done with tail-head chalk or a HeatWatch(®) system, respectively. In Experiment III, a single insemination dose (2.1 × 10⁶ sperm) 12 h after estrus detection (n = 193), a double dose at 12 h (n = 193), or a double dose involving insemination 12 and 24 h after estrus detection (n = 190) did not affect P/AI (87/193 = 45.1%, 85/193 = 44.0%, and 94/190 = 49.5%, respectively; P = 0.51). However, P/AI was influenced by the number of AI service (First, 115/208 = 55.3%(a); Second, 94/204 = 46.1%(a); and Third, 57/165 = 34.8%(b); P = 0.004). In Experiment IV, the P/AI of heifers inseminated from 12 to 16 h after the onset of estrus (40/106 = 37.7%) was less (P = 0.03) than those inseminated from 16.1 to 20 h (85/164 = 51.8%), and 20.1 to 24 h (130/234 = 55.6%). However, the P/AI for heifers inseminated from 24.1 to 30 h (61/134 = 45.5%) did not differ from that of any other interval. In conclusion, in Jersey heifers inseminated with sex-sorted semen, P/AI was not significantly affected by giving GnRH at detection of estrus or a double insemination dose, but it was higher with AI 16.1 to 24 h vs. 12 to 16 h after the onset of estrus. |
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Authors:
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M F Sá Filho; H Ayres; R M Ferreira; M Nichi; M Fosado; E P Campos Filho; P S Baruselli |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-09-15 |
Journal Detail:
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Title: Theriogenology Volume: 74 ISSN: 1879-3231 ISO Abbreviation: Theriogenology Publication Date: 2010 Dec |
Date Detail:
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Created Date: 2010-11-01 Completed Date: - Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 0421510 Medline TA: Theriogenology Country: United States |
Other Details:
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Languages: eng Pagination: 1636-42 Citation Subset: IM |
Copyright Information:
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Copyright © 2010 Elsevier Inc. All rights reserved. |
Affiliation:
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Departamento de Reprodução Animal, FMVZ-USP, CEP 05.508-000, São Paulo, SP, Brasil. |
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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