Genetic relationship of lactation persistency with milk yield, somatic cellscore, reproductive traits, and longevity in Slovak Holstein cattle

摘要

The objective of this study was to estimate the breeding values (BVs) oflactation persistency, the test day of milk yield, the somatic cell score,reproductive traits (calving interval, days open), longevity in SlovakHolstein dairy cattle. BVs were used for the detection of relationships amongthe persistency of lactation and other selected traits. Data for the estimation of BVs of milk production and somatic cell score were collected from 855 240cows. BVs for reproductive traits were estimated for 352 712 cows and forlongevity for 528 362 cows. The highest correlations were confirmed betweenthe BV of persistency and the BV of test day milk yield at 100, 200, and 305 days (−0.88, −0.65, and −0.61). Correlations between the BV of lactation persistency and the BV of somatic cell score at day 305 or the BV of somatic cell score persistency were favorable: −0.05 and −0.12, respectively. The relationship between the BV of persistency and the BV of the calving interval or the BV of days open was 0.11 and 0.10 respectively. The selection for the persistency of lactation may not improve longevity because there is no relation between the BV of persistency andthe BV of longevity ( = 0.06).