HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Spears, J. R. Articles by Cooper, T. Search for Related Content PubMed PubMed Citation Articles by Spears, J. R. Articles by Cooper, T.

Evaluation of Sources of Variance in Dairy Herd Fertility¹

Department of Dairy Science, University of Kentucky, Lexington

ABSTRACT

Fertility data were obtained for the first ten cows bred in 23 herds in each of 22 artificial breeding locals for a period of four consecutive years. Analysis of variance and separation of the components indicated that 1.4% of the variance was due to differences between years. 4.6% to differences between locals, 7.5% was between herds within locals, 2.1% was due to the interaction between years and locals, and 4.9% was due to the interaction between years and herds within locals. The remaining 79.6%, of the variance was estimated to be due to sampling error.

The repeatability of annual herd fertility was estimated to be about 0.15. A frequency distribution graph of actual and expected fertility levels is presented.

¹ The investigation reported in this paper (No. 64-6-26) is in connection with a project of the Kentucky Agricultural Experiment Station and is published with approval of the director. This study was supported in part by grants from the National Association of Artificial Breeders and the Kentucky Artificial Breeding Association.