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 Kratz, J. L. Articles by Becker, R. B. Search for Related Content PubMed Articles by Kratz, J. L. Articles by Becker, R. B.

Vital Statistics of U.S. and Canadian AI Beef Sires^{1 ,2,}

University of Florida, Gainesville 32611

Abstract

Records of U.S. and Canadian Al sires (702 Angus, 675 Herefords, 145 Shorthorns and 183 of 14 other breeds) leaving service during 1949 through 1973 were studied. Mean age at entry into Al service was 3.04 years, and at disposal, 5.70 years. Mean tenures increased from 1.73 years during 1949 to 1954, to 2.98 years during 1970 to 1973. Tenures, adjusted for age at entry, time period and stud by least squares, varied among breeds (P<.01): Angus, 2.75 years; Herefords, 2.48; Shorthorns, 3.23; others, 2.54. Nearly 11% were in service at 10 years of age or older. Causes of loss included injuries, 2.6%; undesirable characteristics of offspring (according to minimum standards of each stud), 15.5%; disease or infection, 7.5%; semen characteristics and low conception rates, 36.4%; problems in collection, 8.9%; miscellaneous, 29.0%. Thirty-seven sires died at the stud, 1224 were sold for slaughter and 444 were returned to natural service. Reasons for disposal were heterogeneous among breeds and among time periods. In recent years, a higher proportion of sires left service for undesirable characteristics of offspring and a lower proportion for low conception rates. The relative number of Shorthorns culled for characteristics of offspring was lower and the number lost for disease and infection higher than for other breeds.

¹ Florida Agricultural Experiment Station Journal Series No. 8097.

² The authors gratefully acknowledge the support of the National Association of Animal Breeders, personnel in artificial insemination studs, and breed registry associations.

³ Illinois Coop. Crop Rep. Serv., Springfield, IL 62705.

⁴ Dairy Science Department.

⁵ Statistics Department.

⁶ Animal Science Department, Louisiana State Uni-versity, Baton Rouge, 70803.