| Seasonal changes in bovine fertility: relation to developmental competence of oocytes, membrane properties and fatty acid composition of follicles. | |
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MedLine Citation:
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PMID: 11226071 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Follicle dynamics and oocyte viability in Holstein primiparous and multiparous cows and the relationships between fertility and the biochemical and physical properties of oocyte membranes with season were examined. The conception rates of primiparous (n = 70 885) and multiparous (n = 143 490) cows differed, peaking in the winter and decreasing in the summer. The number of follicles 3-8 mm in diameter per ovary was higher in winter (19.6) compared with summer (12.0). However, in winter the percentage of ovaries with fewer than ten follicles per ovary was 16%, in contrast to 50% in summer. After aspiration of follicles, 7.5 oocytes per ovary were found in winter and 5.0 oocytes per ovary in summer. Cleavage to the two- to four-cell stage after chemical activation was greater in winter than in summer; this was enhanced at the morula stage and embryo development to the blastocyst stage was significantly higher in winter than in summer. Determination of the lipid phase transition in oocyte membranes revealed a shift of 6 degrees C between summer and winter. Fatty acid composition of phospholipids from follicular fluid, granulosa cells and oocytes indicated that there was a higher percentage of saturated fatty acids during the summer and that the percentages of mono-unsaturated and polyunsaturated fatty acids were higher in oocytes and granulosa cells during the winter. Oocytes and granulosa cells had similar fatty acid compositions, in contrast to follicular fluid. These results may explain the differences in the ability of oocytes to develop to the blastocyst stage at different seasons. Thus, temperature changes may lead to changes in membrane properties, which, in turn, can influence oocyte function and fertility. |
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Authors:
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Y Zeron; A Ocheretny; O Kedar; A Borochov; D Sklan; A Arav |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S. |
Journal Detail:
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Title: Reproduction (Cambridge, England) Volume: 121 ISSN: 1470-1626 ISO Abbreviation: Reproduction Publication Date: 2001 Mar |
Date Detail:
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Created Date: 2001-04-18 Completed Date: 2001-08-30 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 100966036 Medline TA: Reproduction Country: England |
Other Details:
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Languages: eng Pagination: 447-54 Citation Subset: IM |
Affiliation:
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Institute of Animal Science, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Cattle / physiology* Cell Membrane / physiology Cleavage Stage, Ovum Fatty Acids / analysis* Female Fertility* Follicular Fluid / chemistry Granulosa Cells / chemistry Oocytes / chemistry, physiology*, ultrastructure Ovarian Follicle / chemistry* Phospholipids / analysis Seasons* |
| Chemical | |
Reg. No./Substance:
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0/Fatty Acids; 0/Phospholipids |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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