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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1991-1-17
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pubmed:abstractText |
The ovaries of 18 post-partum beef suckler cows were examined daily, using ultrasound, from Day 5 post partum until a normal oestrous cycle was completed. Periods of growth and regression of medium-sized (5-9 mm) follicles were identified before one medium follicle became dominant (single large follicle greater than or equal to 10 mm). The mean (+/- s.e.m.) number of days from parturition to detection of the first post-partum dominant follicle was 10.2 +/- 0.5. The first post-partum dominant follicle ovulated in 2/18 (11%) cows. The interval from calving to first ovulation (mean +/- s.e.m. = 35.9 +/- 3.3 days) was characterized by the growth and regression of a variable number (mean = 3.2 +/- 0.2; range 1-6) of dominant follicles. The maximum diameter of the dominant follicle increased as the cows approached first ovulation (P less than 0.05). Behavioural oestrus was not detected in 16/18 (89%) cows at first ovulation. Following first ovulation, the length of the subsequent cycle was short (mean = 9.7 +/- 0.5 days; range 8-15 days) in 14/18 (78%) cows and was characterized by the development and ovulation of a single dominant follicle. During oestrous cycles of normal length (mean = 20.6 +/- 0.5 days; range 18-23 days) one (N = 2), two (N = 7) or three (N = 8) dominant follicles were identified. The growth rate, maximum diameter or persistence of non-ovulatory dominant follicles before first ovulation or during oestrous cycles were not different (P greater than 0.05). These data show that, in beef suckler cows, follicular development and formation of a dominant follicle occur early after parturition and the incidence of ovulation of the first dominant follicle is low. The number of dominant follicles that develop before first ovulation is variable; first ovulation is rarely associated with oestrus and short cycles are common after first ovulation. It is concluded that prolonged anoestrus in post-partum beef suckler cows is due to lack of ovulation of a dominant follicle rather than delayed development of dominant follicles.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
0022-4251
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
90
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
523-33
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:2250250-Animals,
pubmed-meshheading:2250250-Cattle,
pubmed-meshheading:2250250-Estrus,
pubmed-meshheading:2250250-Female,
pubmed-meshheading:2250250-Lactation,
pubmed-meshheading:2250250-Ovarian Follicle,
pubmed-meshheading:2250250-Ovary,
pubmed-meshheading:2250250-Ovulation,
pubmed-meshheading:2250250-Postpartum Period,
pubmed-meshheading:2250250-Pregnancy,
pubmed-meshheading:2250250-Time Factors
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pubmed:year |
1990
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pubmed:articleTitle |
Pattern of follicular growth and resumption of ovarian activity in post-partum beef suckler cows.
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pubmed:affiliation |
Agricultural and Veterinary Biotechnology Centre, Faculty of Veterinary Medicine, University College Dublin, Ireland.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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