spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online November 10, 2003
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Vézina, F.
Right arrow Articles by Williams, T. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Vézina, F.
Right arrow Articles by Williams, T. D.
The Journal of Experimental Biology 206, 4443-4451 (2003)
doi: 10.1242/jeb.00702

The metabolic cost of avian egg formation: possible impact of yolk precursor production?

François Vézina*, Katrina G. Salvante and Tony D. Williams

Department of Biological Sciences, Simon Fraser University, Burnaby, 8888 University Drive, Burnaby, V5A 1S6, Canada

* Author for correspondence (e-mail: fvezina{at}sfu.ca)

Accepted 2 September 2003

Little is known about the energy costs of egg production in birds. We showed in previous papers that, during egg production, European starlings (Sturnus vulgaris) undergo a 22% increase in resting metabolic rate (RMR) and that the maintenance and activity costs of the oviduct are responsible for 18% of the variation in elevated laying RMR. Therefore, other energy-consuming physiological mechanisms must be responsible for the remaining unexplained variation in elevated laying RMR. Yolk precursor [vitellogenin (VTG) and very-low-density lipoprotein (VLDL)] production is likely to be costly because it signifies a marked increase in the biosynthetic activity of the liver. We documented the pattern of yolk precursor production in response to daily injections of 17ß-estradiol (E2) in zebra finches (Taeniopygia guttata). Based on this pattern we carried out an experiment in order to evaluate the metabolic costs of producing VTG and VLDL. Our E2 treatment resulted in a significant increase in plasma VTG and VLDL levels within the natural breeding range for the species. Although RMR was measured during the period of active hepatic yolk precursor production, it did not differ significantly within individuals in response to the treatment or when comparing E2-treated birds with sham-injected birds. This could mean that yolk precursor production represents low energy investment. However, we discuss these results in light of possible adjustments between organs that could result in energy compensation.

Key words: egg production, energy cost, resting metabolic rate, RMR, vitellogenin, very-low-density lipoprotein, zebra finch, Taeniopygia guttata, yolk precursor production




This article has been cited by other articles:


Home page
 J. Exp. Biol.Home page
E. C. Wagner, J. S. Prevolsek, K. E. Wynne-Edwards, and T. D. Williams
Hematological changes associated with egg production: estrogen dependence and repeatability
J. Exp. Biol., February 1, 2008; 211(3): 400 - 408.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
F. Vezina and T. D. Williams
The metabolic cost of egg production is repeatable
J. Exp. Biol., July 1, 2005; 208(13): 2533 - 2538.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
K. Phillips
EFFORTLESS EGG LAYING?
J. Exp. Biol., December 15, 2003; 206(24): 4381 - 4381.
[Full Text] [PDF]


© The Company of Biologists Ltd 2003