Elsevier

Journal of Dairy Science

Volume 83, Issue 11, November 2000, Pages 2664-2671
Journal of Dairy Science

Article
The Genetic Relationship between Calving Interval, Body Condition Score and Linear Type and Management Traits in Registered Holsteins

https://doi.org/10.3168/jds.S0022-0302(00)75160-5Get rights and content
Under an Elsevier user license
open archive

Abstract

The trend to poorer fertility in dairy cattle with rising genetic merit for production over the last decade suggests that breeding goals need to be broadened to include fertility. This requires reliable estimates of genetic (co)variances for fertility and other traits of economic importance. In the United Kingdom at present, reliable information on calving dates and hence calving intervals are available for most dairy cows. Data in this study consisted of 44,672 records from first lactation heifers on condition score, linear type score, and management traits in addition to 19,042 calving interval records. Animal model REML was used to estimate (co)variance components. Genetic correlations of body condition score (BCS) and angularity with calving interval were −0.40 and 0.47, respectively, thus cows that are thinner and more angular have longer calving intervals. Genetic correlations between calving interval and milk, fat, and protein yields were between 0.56 and 0.61. Records of phenotypic calving interval were regressed on sire breeding values for BCS estimated from records taken at different months of lactation and breeding values for BCS change. Genetic correlations inferred from these regressions showed that BCS recorded 1 mo after calving had the largest genetic correlation with calving interval in first lactation cows. It may be possible to combine information on calving interval, BCS, and angularity into an index to predict genetic merit for fertility.

Key words

calving interval
body condition score
energy balance

Abbreviation key

CI
calving interval
VCE
variance component estimation

Cited by (0)