Poult. Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
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 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 Grossman, M
Right arrow Articles by Koops, W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Grossman, M
Right arrow Articles by Koops, W.
Poultry Science, Vol 79, Issue 12, 1715-1724
Copyright © 2000 by Poultry Science Association

Articles

A model for persistency of egg production

M Grossman, TN Gossman, and WJ Koops

Department of Animal Sciences, University of Illinois, Urbana 61801, USA. mikeg@uiuc.edu

The objectives of our study were to propose a new definition for persistency of egg production and to develop a mathematical model to describe the egg production curve, one that includes a new measure for persistency, based on the proposed definition, for use as a selection criterion to improve total egg production. Persistency of egg production is an important determining factor for total egg production. Hens with the same total production, however, can exhibit different egg production curves because of differences in persistency. We propose a new definition for persistency of egg production: the number of weeks during which a level of constant production is maintained. No egg production model exists that includes a measure of persistency in terms of duration of time or that allows this measure of persistency to be derived from model parameters. It was necessary, therefore, to develop a new model to describe an egg production curve for a flock: equation [see text] and for an individual: equation [see text] where y(t) = egg production at time t, t1 and t2 = times at transition, r = duration of transition, y(p) = level of constant production, b4 = rate of decline in production, and P = persistency of constant production. These parameters measure directly the important biological characteristics of an egg production curve. To illustrate the model, six data sets were used: two from flocks (one pullet flock and one hen flock) and four from two pairs of individuals. The proposed definition of persistency should be important for genetic selection because it might be desirable to select for increased persistency. The novel approach to the definition and measure of persistency presented here should provide a better understanding of the relationship between the new measure of persistency and other characteristics of egg production.


This article has been cited by other articles:


Home page
 Poult. Sci.Home page
A. Kranis, G. Su, D. Sorensen, and J. A. Woolliams
The Application of Random Regression Models in the Genetic Analysis of Monthly Egg Production in Turkeys and a Comparison with Alternative Longitudinal Models
Poult. Sci., March 1, 2007; 86(3): 470 - 475.
[Abstract] [Full Text] [PDF]

Home page
 Poult. Sci.Home page
C. Senthilkumaran, S. Peterson, M. Taylor, and G. Bedecarrats
Use of a vascular access port for the measurement of pulsatile luteinizing hormone in old broiler breeders.
Poult. Sci., September 1, 2006; 85(9): 1632 - 1640.
[Abstract] [Full Text] [PDF]

Home page
 Biol. Reprod.Home page
H.-K. Liu, D.W. Long, and W.L. Bacon
Interval Between Preovulatory Surges of Luteinizing Hormone Increases Late in the Reproductive Period in Turkey Hens
Biol Reprod, April 1, 2002; 66(4): 1068 - 1075.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2000 by the Poultry Science Association.