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 Christian, L. L. Articles by Chapman, A. B. Search for Related Content PubMed PubMed Citation Articles by Christian, L. L. Articles by Chapman, A. B.

Heritability Estimates in Beef Cattle Based on Identical and Fraternal Twin Data¹

University of Wisconsin^,4, Madison

Abstract

Heritability estimates of growth and production traits based on 18 pairs of fraternal twins and 12 pairs of identical twin Hereford heifers are presented. The twins were collected from beef cattle herds throughout the midwest and placed on a uniformity trial. Estimates were made by two methods: the intraclass correlation of identical twins, and using the intrapair variances of both identical and fraternal twins. For most traits both methods yielded estimates larger than those reported from non-twin data. The greatest discrepancies were for traits expressed early in life. These differences are discussed in terms of greater environmental control achieved in twin studies, nonadditive genetic variation and maternal influence.

¹ Published with the approval of the Director of the Wisconsin Agricultural Experiment Station, and conducted in cooperation with the North Central Regional Project NC-1, The improvement of Beef Cattle through Breeding Methods.

² Present address: Department of Animal Husbandry-Veterinary Science, University of Tennessee, Knoxville, Tennessee.

³ The assistance of Elmer Kohlstedt and Cecil Hartung in the early years of this project is greatly appreciated.

⁴ Paper No. 984 from the Division of Genetics and No. 394 from the Department of Meat and Animal Science.