CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Reproduction, Fertility and Development   
Reproduction, Fertility and Development
Journal Banner
  Vertebrate reproductive science and technology
 
blank image Search
 
blank image blank image
blank image
 
  Advanced Search
   

Journal Home
About the Journal
Editorial Structure
Contacts
Content
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Virtual Issues
Sample Issue
For Authors
General Information
Scope
Submit Article
Author Instructions
Open Access
Awards and Prizes
For Referees
Referee Guidelines
Review an Article
Annual Referee Index
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates
Library Recommendation

blue arrow e-Alerts
blank image
Subscribe to our email Early Alert or RSS feeds for the latest journal papers.

red arrow Connect with us
blank image
facebook twitter logo LinkedIn

red arrow Connect with SRB
blank image
facebook TwitterIcon

Affiliated Societies

RFD is the official journal of the International Embryo Transfer Society and the Society for Reproductive Biology.


 

Article << Previous     |     Next >>   Contents Vol 4(3)

Nutrition-progesterone interactions during early pregnancy in sheep

RA Parr

Reproduction, Fertility and Development 4(3) 297 - 300
Published: 1992

Abstract

A series of studies was undertaken to determine the relationship between level of feed intake during early pregnancy, concentrations of peripheral progesterone and embryo survival in sheep. Ewes fed twice maintenance (2M) rations after joining had a pregnancy rate of 48%. Ewes fed 2M rations and given exogenous progesterone between 8 and 14 days after mating had a pregnancy rate of 76%. Ewes fed rations calculated to maintain live weight (maintenance, M) or fed restricted rations during this same time had pregnancy rates ranging from 60 to 68%, with no beneficial effect of progesterone supplement. Concentrations of peripheral plasma progesterone on Day 12 after mating were inversely related to the level of feed intake; this relationship reflected an increase in the metabolic clearance rate of progesterone with increased feed intake (1/2M, M and 2M) without concomitant changes in the entry rate of the hormone. Injection of epostane, an inhibitor of the enzyme 3 beta-hydroxysteroid dehydrogenase, caused 'windows' of progesterone reduction for 48-h periods over Days 9-13 after mating. The sheep embryo was sensitive to low peripheral plasma progesterone concentrations only on Days 11 and 12 after mating. Blood flow rates in the portal vein of ewes fed either 1/2M, M or 2M rations for 7 days were directly related to the level of feed intake.(ABSTRACT TRUNCATED AT 250 WORDS)



Full text doi:10.1071/RD9920297

© CSIRO 1992

blank image
Subscriber Login
Username:
Password:  

 
PDF (210 KB) $25
 Export Citation
 Print
  
    
Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2016