|
|
||||||||
Oregon State University,2, Corvallis 97331 and University of Arizona, Tucson 85721
Abstract
Thirty years and 23 yr of life history data from a Hereford herd in Arizona and an Angus herd in Wyoming, respectively, were analyzed. Longevity averaged 4.21 ± .06 for years from first calving to disposal (FST), 7.40 ± .06 for years from birth to disposal (AGE) and 3.46 ± .06 for lifetime number of calves weaned (NUM) in Herefords and 4.49 ± .13 (FST), 6.68 ± .12 (AGE) and 3.66 ± .11 (NUM) in Angus. In the Hereford herd, heritability estimates for traits measuring longevity, estimated from daughter-dam regression and paternal half-sib analyses, ranged from .16 to .26. In the Angus herd, heritability estimates from daughter-dam regression ranged from .03 to .05. In the Hereford herd, genetic correlations of birth weight and weaning weight with longevity, from daughter-dam regression, were negative and generally of low magnitude, whereas genetic correlations between weaning condition score and longevity were positive and moderate. Analogous estimates from paternal half-sib analyses all were positive and moderate to high. Phenotypic correlations between early life traits and longevity traits in Herefords all were near zero. In the Angus herd, curves for age-specific survivorship and age-specific survival rate varied markedly among sires. This study suggested the existence of moderate genetic variation for longevity traits in beef cattle. None of the traits expressed early in life that were examined would, however, be reliable predictors of genetic or phenotypic merit for longevity.
1 Tech. paper no. 8274, Oregon Agric. Exp. Sta.
2 Dept. of Anim. Sci., Oregon State Univ.
3 Current Address: Azabu Univ., 1-17-71, Fuchinobe, Sagamihara-shi, Kanagawa-ken, 229 Japan.
4 Current address: Dept. of Anim. Sci., Virginia Polytechnic Institute and State Univ., Blacksburg VA 24061.
5 Dept. of Anim. Sci., Univ. of Arizona.
This article has been cited by other articles:
![]() |
G. E. Martinez, R. M. Koch, L. V. Cundiff, K. E. Gregory, and L. D. Van Vleck Number of calves born, number of calves weaned, and cumulative weaning weight as measures of lifetime production for Hereford cows J Anim Sci, July 1, 2004; 82(7): 1903 - 1911. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. E. Martinez, R. M. Koch, L. V. Cundiff, K. E. Gregory, and L. D. Van Vleck Genetic parameters for six measures of length of productive life and three measures of lifetime production by 6 yr after first calving for Hereford cows J Anim Sci, July 1, 2004; 82(7): 1912 - 1918. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |