Epc. Koenen et al., Genetic analysis of body condition score of lactating dutch Holstein and Red-and-White heifers, J DAIRY SCI, 84(5), 2001, pp. 1265-1270
The aim of this study was to estimate phenotypic and genetic parameters for
body condition scores (BCS) from the Dutch type classification system. Dat
a included 108,809 Holstein (H) and 26,208 Red-and-White (R) heifers from 9
701 herds that were scored once during lactation on a 1 to 9 scale (1 = ema
ciated and 9 = obese). Mean BCS for H and R data were 4.50 and 4.94, respec
tively. The BCS decreased as the percentage of Holstein genes increased. Fo
r both breeds, BCS after calving was about 5.6 and BCS was lowest around wk
11. For H heifers, mean BCS at drying off was about 0.8 lower than BCS at
calving, whereas for R heifers BCS was at about the same level as at calvin
g. Variance components were estimated using an animal model including the e
ffects of herd x visit, classifier, age at calving, DIM, and genetic group.
The random herd x visit effect explained about 10 to 15% of the phenotypic
variation. Heritabilities ranged from 0.24 to 0.38, depending on breed and
lactation period. Genetic correlations between BCS observations in bimonth
ly lactation periods were close to unity, especially for H. It was conclude
d that BCS data collected by type classifiers can well be used for genetic
evaluation and that genetic variation between animals for BCS-change patter
ns is a small component of the overall variation in BCS.