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 Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Minyard, J. A. Articles by Dinkel, C. A. Search for Related Content PubMed Articles by Minyard, J. A. Articles by Dinkel, C. A.

Weaning Weight of Beef Calves as Affected by Age and Sex of Calf and Age of Dam¹

South Dakota State University, Brookings

Abstract

The weaning records of 2351 purebred Hereford and Angus calves were analyzed to evaluate the influence of age of calf, sex of calf and age of dam on calf weaning weight.

Age of calf at weaning was shown to have a highly significant influence on weaning weight. The linear regression of weight on age within ranch-year-month-of-birth subclasses was 1.20 lb. Two methods of calf age adjustment were evaluated. One method was based on individual growth rate, and the second method also considered the average growth rate of the group. The second appeared to be the most efficient.

Two methods of sex adjustment were compared, an additive factor and a multiplicative factor representing the ratio of sex means. The multiplicative adjustment factor was more effective, and its use is indicated by these data.

The data indicated a highly significant age-of-dam effect on calf weaning weight. Weaning weights were lowest among calves from 2-year-old cows and showed the largest change between the ages of 2 and 3 years. Maximum production was reached at 8 years of age. The adjustments obtained from this study are in reasonably close agreement with those that have been reported.

¹ Department of Animal Science, published with the approval of the Director of the South Dakota Agricultural Experiment Station as Publication No. 640 of the Journal Series. Cooperative with A.R.S., U.S.D.A. and a contribution from Regional Project NC-1, Improvement of Beef Cattle through Breeding Methods.

² This paper represents part of a thesis submitted by the senior author to the Graduate Faculty of South Dakota State University as partial fulfillment of the requirements for the degree of Master of Science.

³ Appreciation is extended to Henry P. Holzman, Associate Animal Husbandman Emeritus, South Dakota State University Extension Service, for making the data available for this study.