| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Centre for Genetic Improvement of Livestock, Department of Animal and Poultry Science, University of Guelph Guelph, ON, Canada N1G 2W1
A total of 65,491 lactation means of log2-transformed SCC measures were analyzed from first lactation Holstein cows in Ontario. Effects of inbreeding on SCC were estimated by a nonadditive sire and dam model that included additive, dominance, and additive by additive genetic effects and regression of lactation somatic cell score on inbreeding coefficients of the cows. Variance components were estimated using the tildehat approximation to REML. Solutions were by iteration on data. Estimates of heritability for lactation somatic cell score in the narrow sense were .165 and in the broad sense were .203. The additive by additive component (2.5% of the total phenotypic variance) was almost twice as large as the dominance component (1.3%). The regression coefficient of lactation somatic cell score per 1% increase of inbreeding was .012. The average increase of the population mean of lactation somatic cell score caused by a 10% increase of inbreeding coefficient was estimated to be 10.5% of the original phenotypic standard deviation of 1.153. The inbreeding depression was thus relatively low, but, on average, inbred animals tended to have higher lactation somatic cell score. This study provides preliminary evidence that inbreeding is related to disease prevalence in large purebred dairy populations.
Key Words: dairy cattle • somatic cells • inbreeding depression • nonadditive genetic variances
Submitted on June 10, 1994
Accepted on February 27, 1995
This article has been cited by other articles:
|
|
 |
|
  S. M. Parland, J. F. Kearney, M. Rath, and D. P. Berry Inbreeding Effects on Milk Production, Calving Performance, Fertility, and Conformation in Irish Holstein-Friesians J Dairy Sci, September 1, 2007; 90(9): 4411 - 4419. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Mc Parland, J. F. Kearney, M. Rath, and D. P. Berry Inbreeding trends and pedigree analysis of Irish dairy and beef cattle populations J Anim Sci, February 1, 2007; 85(2): 322 - 331. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Croquet, P. Mayeres, A. Gillon, H. Hammami, H. Soyeurt, S. Vanderick, and N. Gengler Linear and Curvilinear Effects of Inbreeding on Production Traits for Walloon Holstein Cows J Dairy Sci, January 1, 2007; 90(1): 465 - 471. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Gulisija, D. Gianola, and K. A. Weigel Nonparametric Analysis of the Impact of Inbreeding on Production in Jersey Cows J Dairy Sci, January 1, 2007; 90(1): 493 - 500. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. C. Sorensen, P. Madsen, M. K. Sorensen, and P. Berg Udder health shows inbreeding depression in danish holsteins. J Dairy Sci, October 1, 2006; 89(10): 4077 - 4082. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Sewalem, G. J. Kistemaker, F. Miglior, and B. J. Van Doormaal Analysis of inbreeding and its relationship with functional longevity in Canadian dairy cattle. J Dairy Sci, June 1, 2006; 89(6): 2210 - 2216. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Croquet, P. Mayeres, A. Gillon, S. Vanderick, and N. Gengler Inbreeding depression for global and partial economic indexes, production, type, and functional traits. J Dairy Sci, June 1, 2006; 89(6): 2257 - 2267. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
