|
|
||||||||
Journal of Animal Science, Vol 79, Issue 1 52-59, Copyright © 2001 by American Society of Animal Science
JOURNAL ARTICLE |
G. L. Bennett and K. E. Gregory
USDA, ARS, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, NE 68933-0166, USA. bennett@email.marc.usda.gov
There is limited genetic information relating calving difficulty and body weights to other productive and reproductive traits. Such information is useful for specifying selection criteria and for predicting economic consequences of selection. Genetic, maternal, and environmental covariances of six productive and reproductive measurements with calving difficulty, birth weight, 200-d weight, and 168-d postweaning gain were estimated in 12 experimental populations of cattle. Calf (direct) genetic effects resulting in longer gestation length were associated with increased calving difficulty and birth weight. Maternal genetic effects of increased gestation length and heavier birth weight were significantly associated. Lighter birth weight and reduced calving difficulty were associated with earlier heifer age at puberty. Increases in direct genetic effects of calving difficulty, 200-d weight, and postweaning gain were associated with a small increase in direct effect of scrotal circumference. Increased direct genetic effects of scrotal circumference were correlated with maternal effects decreasing calving difficulty and increasing 200-d weight. Direct effects of the skeletal measurements, yearling hip height, and heifer pelvic area were positively correlated with direct effects of calving difficulty, birth weight, 200-d weight, and postweaning gain, positively correlated with maternal effects for birth weight and 200-d weight, and negatively correlated with maternal calving difficulty. Percentage of retail product was positively associated with calving difficulty and negatively associated with 168-d gain. Predicted genetic change in calving difficulty resulting from one standard deviation of selection for either calving difficulty score or birth weight was much larger than for any other traits. Selection for 200-d weight, 168-d postweaning gain, hip height, pelvic area, or scrotal circumference was predicted to have opposite effects on direct and maternal calving difficulty. Estimated genetic correlations indicate some small to moderate relationships between calving difficulty and the measured productive and reproductive traits. However, selection for reduced calving difficulty should be based on calving difficulty score and(or) birth weight because of their superiority in predicted genetic change.
This article has been cited by other articles:
![]() |
F. D. N. Mujibi and D. H. Crews Jr. Genetic parameters for calving ease, gestation length, and birth weight in Charolais cattle J Anim Sci, September 1, 2009; 87(9): 2759 - 2766. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. L. Bennett, R. M. Thallman, W. M. Snelling, and L. A. Kuehn Experimental selection for calving ease and postnatal growth in seven cattle populations. II. Phenotypic differences J Anim Sci, September 1, 2008; 86(9): 2103 - 2114. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. L. Bennett Experimental selection for calving ease and postnatal growth in seven cattle populations. I. Changes in estimated breeding values J Anim Sci, September 1, 2008; 86(9): 2093 - 2102. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. A. Perry, M. F. Smith, A. J. Roberts, M. D. MacNeil, and T. W. Geary Relationship between size of the ovulatory follicle and pregnancy success in beef heifers J Anim Sci, March 1, 2007; 85(3): 684 - 689. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. C. Lamb, J. E. Larson, T. W. Geary, J. S. Stevenson, S. K. Johnson, M. L. Day, R. P. Ansotegui, D. J. Kesler, J. M. DeJarnette, and D. G. Landblom Synchronization of estrus and artificial insemination in replacement beef heifers using gonadotropin-releasing hormone, prostaglandin F2{alpha}, and progesterone J Anim Sci, November 1, 2006; 84(11): 3000 - 3009. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Crews Jr. Age of dam and sex of calf adjustments and genetic parameters for gestation length in Charolais cattle J Anim Sci, January 1, 2006; 84(1): 25 - 31. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Eriksson, A. Nasholm, K. Johansson, and J. Philipsson Genetic relationships between calving and carcass traits for Charolais and Hereford cattle in Sweden J Anim Sci, August 1, 2004; 82(8): 2269 - 2276. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Abeni, G. Bergoglio, G. Masoero, G. M. Terzano, and S. Allegrini Plasma hormones and metabolites in Piedmontese cows during late pregnancy: Relationships with calf birth weight J Anim Sci, February 1, 2004; 82(2): 438 - 444. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |