Type

Journal Article

Authors

R. F. Veerkamp
M Rath
R. D. Evans
P Dillon
F Buckley
D P Berry

Subjects

Veterinary

Topics
pregnancy female milk cattle multivariate analysis fertility animals genetics body constitution male pregnancy rate regression analysis secretion genetic variation physiology body weight lactation

Genetic parameters for body condition score, body weight, milk yield, and fertility estimated using random regression models. (2003)

Abstract Genetic (co)variances between body condition score (BCS), body weight (BW), milk yield, and fertility were estimated using a random regression animal model extended to multivariate analysis. The data analyzed included 81,313 BCS observations, 91,937 BW observations, and 100,458 milk test-day yields from 8725 multiparous Holstein-Friesian cows. A cubic random regression was sufficient to model the changing genetic variances for BCS, BW, and milk across different days in milk. The genetic correlations between BCS and fertility changed little over the lactation; genetic correlations between BCS and interval to first service and between BCS and pregnancy rate to first service varied from -0.47 to -0.31, and from 0.15 to 0.38, respectively. This suggests that maximum genetic gain in fertility from indirect selection on BCS should be based on measurements taken in midlactation when the genetic variance for BCS is largest. Selection for increased BW resulted in shorter intervals to first service, but more services and poorer pregnancy rates; genetic correlations between BW and pregnancy rate to first service varied from -0.52 to -0.45. Genetic selection for higher lactation milk yield alone through selection on increased milk yield in early lactation is likely to have a more deleterious effect on genetic merit for fertility than selection on higher milk yield in late lactation.
Collections Ireland -> Teagasc -> PubMed

Full list of authors on original publication

R. F. Veerkamp, M Rath, R. D. Evans, P Dillon, F Buckley, D P Berry

Experts in our system

1
R. F. Veerkamp
Teagasc
Total Publications: 20
 
2
R. D. Evans
Teagasc
Total Publications: 44
 
3
P Dillon
Teagasc
Total Publications: 54
 
4
F Buckley
Teagasc
Total Publications: 57
 
5
D P Berry
Teagasc
Total Publications: 243