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 Wiltbank, J. N. Search for Related Content PubMed Articles by Wiltbank, J. N.

Management Programs to Increase Reproductive Efficiency of Beef Herds^{1, 2,}

Colorado State University, Fort Collins 80521

Abstract

A Management system was developed so that heifers calved early with their first calf. The system increased the proportion of cows showing estrus and calving early in subsequent years. Cows calved early in the NM group with the first calf because more heifers than needed as replacements were exposed to the bull, heifers that became pregnant early in the breeding season were selected as replacements, heifers were bred 20 days earlier than the cows, the breeding season was shortened to 45 days and estrous synchronization was used.

Improving the level of nutrition and shortening the breeding season increased the number of cows showing estrus and becoming pregnant during the AI period in two commercial cow herds. Some success was noted when an attempt was made to predict the reproductive performance in these two cow herds. The feasibility of assessing the economic advantage of different management systems was also explored.

¹ Appreciation is expressed to the American Breeders Service, DeForest, Wisconsin, for supplying heifers and funds in support of this study.

² Published with the approval of the Director of the Colorado State University Experiment Station as Scientific Series Paper No. 1922.

³ Appreciation is expressed to Mr. D. G. LeFever for supervising the collection of most of the data and to the following graduate students for their help and stimulation, S. Roberts, J. C. Spitzer, B. Bennett, and G. Mukembo.