Document Detail


Physiological effects of undernutrition on postpartum anoestrus in cows.
MedLine Citation:
PMID:  7623336     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The focus of this review is the physiological effects of undernutrition on ovarian follicle growth and the occurrence of ovulation in postpartum cows. Evidence suggests that moderate levels of underfeeding, before or after calving, may interfere with the mechanism(s) of final follicle maturation and ovulation, whereas more pronounced nutritional deficiencies may affect the mechanism(s) regulating dominant follicle size and the dynamics of dominant follicle growth and regression. Severe undernutrition may result in the absence of follicles > 5 mm in diameter. These changes are consistent with likely effects of reduced LH or FSH secretion that have been associated with inhibition of both tonic and surge release of GnRH from the hypothalamus. As yet, there is no direct evidence for local effects of undernutrition on ovarian function in cows, and studies examining this tissue often ignore dynamic interdependencies between the hypothalamus, anterior pituitary gland, and the ovaries, and possible nutritional modulation of ovarian feedback mechanisms that affect gonadotrophin secretion. Further research is required to elucidate nutritional effects on the positive feedback regulation of gonadotrophin secretion and on the expression of behavioural oestrus. Further studies are also needed to determine whether nutritional or metabolic state may influence ovarian function directly in a manner that affects the duration of postpartum anoestrus and fertility in postpartum cows.
Authors:
P D Jolly; S McDougall; L A Fitzpatrick; K L Macmillan; K W Entwistle
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Review    
Journal Detail:
Title:  Journal of reproduction and fertility. Supplement     Volume:  49     ISSN:  0449-3087     ISO Abbreviation:  J. Reprod. Fertil. Suppl.     Publication Date:  1995  
Date Detail:
Created Date:  1995-08-28     Completed Date:  1995-08-28     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0225652     Medline TA:  J Reprod Fertil Suppl     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  477-92     Citation Subset:  IM    
Affiliation:
Department of Biomedical and Tropical Veterinary Sciences, James Cook University of North Queensland, Townsville, Australia.
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MeSH Terms
Descriptor/Qualifier:
Anestrus*
Animal Nutritional Physiological Phenomena*
Animals
Cattle / physiology*
Female
Gonadotropins, Pituitary / metabolism
Models, Biological
Nutrition Disorders*
Ovarian Follicle / physiology
Postpartum Period*
Pregnancy
Chemical
Reg. No./Substance:
0/Gonadotropins, Pituitary

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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