| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Station de Génétique Quantitative et Appliquée, Institut National de la Recherche Agronomique, Jouy-en-Josas, 78350, France
Breeding values and genetic parameters for dystocia were estimated in Normande and Holstein breeds. Dystocia scores were related to an underlying continuous variable via a threshold model. ?he underlying linear model included the effects of calving season, sex of calf by parity of dam, sire of calf, grandsire of calf, dam within maternal grandsire and herd-year effects. Typical results were found for the environmental effects, with a strong influence of dam parity on dystocia, a strong influence of sex of calf, and a small effect of calving season. Herd-year variances were 32 and 40% of the residual variance in the Normande and Holstein breeds, respectively. Heritabilities for the Normande (Holstein) breed were .08 (.07) for direct effects and .11 (.07) for maternal effects. Correlations between sire and grandsire effects were .51 and .36 for the Normande and Holstein breeds, respectively. The corresponding correlations between direct and maternal effects were .15 and –.09. The results of this study show that a complete model for dystocia including the threshold concept and maternal effects can be applied for routine evaluation of dairy AI bulls. Maternal effects are important, and they should be considered in dystocia analysis, especially if nonrandom mating is present. Selection for reducing dystocia in calf and cow effects are not antagonistic.
Key Words: threshold model • dystocia • genetic parameters
Submitted on August 23, 1990
Accepted on October 31, 1990
This article has been cited by other articles:
|
|
 |
|
  D. P. Berry, J. M. Lee, K. A. Macdonald, and J. R. Roche Body Condition Score and Body Weight Effects on Dystocia and Stillbirths and Consequent Effects on Postcalving Performance J Dairy Sci, September 1, 2007; 90(9): 4201 - 4211. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. M. Hickey, M. G. Keane, D. A. Kenny, A. R. Cromie, P. R. Amer, and R. F. Veerkamp Heterogeneity of Genetic Parameters for Calving Difficulty in Holstein Heifers in Ireland J Dairy Sci, August 1, 2007; 90(8): 3900 - 3908. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. P. Van Tassell, G. R. Wiggans, and I. Misztal Implementation of a Sire-Maternal Grandsire Model for Evaluation of Calving Ease in the United States J Dairy Sci, October 1, 2003; 86(10): 3366 - 3373. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Steinbock, A. Nasholm, B. Berglund, K. Johansson, and J. Philipsson Genetic Effects on Stillbirth and Calving Difficulty in Swedish Holsteins at First and Second Calving J Dairy Sci, June 1, 2003; 86(6): 2228 - 2235. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Hansen, P. Madsen, J. Jensen, J. Pedersen, and L. G. Christensen Genetic Parameters of Postnatal Mortality in Danish Holstein Calves J Dairy Sci, May 1, 2003; 86(5): 1807 - 1817. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
