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


     

J. Anim Sci. 1982. 54:235-240.
© 1982 American Society of Animal Science
This Article
Right arrow Full Text (PDF)
Right arrow A correction has been published
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 Google Scholar
Google Scholar
Right arrow Articles by Bereskin, B
Right arrow Articles by Norton, H. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bereskin, B
Right arrow Articles by Norton, H. W.

Adjusting Preweaning Pig Weights to a Standard Age1

B Bereskin2 and H. W. Norton3

US Department of Agriculture, Beltsville, MD 20705 and and the University of Illinois, Urbana 61801

Abstract

Quadratic regression equations were fitted to preweaning weight records for 3,587 Duroc and Yorkshire pigs in 533 litters farrowed in the spring and fall from 1974 through 1978 at the Beltsville Agricultural Research Center. The objective was to derive factors for adjusting pig and litter weights to uniform ages for use in evaluating sow productivity. Only records for litters with at least two boar and two gilt pigs alive at weaning at 42 d of age were included. Records for up to four healthy pigs of each sex in each litter were used. Pig weights were recorded shortly after birth and at approximately 21 and 42 d of age. Actual weights were transformed to natural logarithms prior to analysis. Quadratic regression equations were fitted for each of the 1,066 litter-sex subgroups. The computed least-squares mean and linear and quadratic regression coefficients from all subgroups were analyzed with a model that included effects of years, seasons, breeds, sex and all interactions. On the basis of significant season and year X season X breed interaction effects, the quadratic coefficient was required for a good fit of the equation to the data. The equation Y = .2127 + .07545 (days of age)—.000558 (days of age)2, where Y = estimated pig weight in natural logarithms, was then used to calculate multiplicative factors for adjusting preweaning pig and litter weights to ages of 14, 21,28, 35 and 42 d.

Footnotes

1 The authors express appreciation to W. H. Peters, swine operations supervisor, and R. L. Figulski, swine herdsman, for managing the swine herd and providing valuable technical assistance during the study.

2 Research Geneticist, Nonruminant Animal Nutrition Laboratory, Animal Science Institute, NER, ARS,Beltsville, MD 20705

3 Professor, Dept. of Anim. Sci., Univ. of Illinois, Urbana 61801.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1982 by the American Society of Animal Science.