Linked Life Data

12141575

Source:http://linkedlifedata.com/resource/pubmed/id/12141575

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2002-7-26
pubmed:abstractText
Repeat breeding occurs at an incidence of 10% in the Swedish dairy cow population. Evidence is available for a hormonal asynchrony around estrus in repeat-breeder heifers (RBH). This asynchrony seems to be the underlying cause for a series of dysfunctions such as prolonged standing estrus and delayed ovulation, leading to fertilization failure. For further determinations of repeat-breeder estrous cycle characteristics, seven strictly selected RBH and six virgin heifers (VH) were studied during 3-7 consecutive cycles, with particular attention paid to the estrous period. Follicular dynamics were studied by ultrasonography and related to estrous behavior and pattern of sexual hormones (progesterone, estradiol-17beta, and LH) in peripheral circulation. Mean group data were compared and a classification model was designed. The most prominent findings for RBH were prolonged duration of estrus, delayed LH peak, prolonged lifespan of the preovulatory follicle, and a late postovulatory rise in plasma progesterone. There was also a strong tendency for peri-ovulatory suprabasal progesterone levels in RBH. It is suspected that these deviations cause changes in the microenvironment of the preovulatory follicle, negatively affecting the final maturation of the oocyte. The heterogeneity of the RBH group underlines the multifactorial cause of the repeat-breeder syndrome. The VH formed a homogenous group with data varying within physiological limits. A classification model based on three characteristic variables managed to identify 81% of the VH and 79% of the RBH correctly. Results from this study propose that some heifers have general, consistent problems in synchronizing estrous events, displayed as varying symptoms in the course of consecutive estrous cycles. These subfertile animals could be classified as repeat-breeders.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0093-691X
pubmed:author
pubmed:issnType
Print
pubmed:volume
57
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2257-69
pubmed:dateRevised
2009-11-3
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Repeat breeding in dairy heifers: follicular dynamics and estrous cycle characteristics in relation to sexual hormone patterns.
pubmed:affiliation
Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, Center for Reproductive Biology in Uppsala, Swedish University of Agricultural Sciences. renee.bage@og.slu.se
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't