Detailed Dairy Cattle Evaluation Information
2019/02/06
Genetic evaluation for type traits
The following 5 score traits (4 components and a overall confomation) and 18 linear traits are currently evaluated: dairy strength, overall udder, flame (include rump), overall feet & legs and overall conformation (final score) as score traits; stature, chest width, body depth, angularity, BCS (body condition score), rump angle, pin bone width (rump width), rear legs -side view, rear legs -rear view, foot angle, fore udder, rear udder height, rear udder width, udder support, udder depth, front teat placement, rear teat placement and teat length. Type classification data have been widely collected since 1982 by HCAJ.
 
The data editing criteria are:
 
sire evaluation
sires known,
record at first-third lactation (calving),
18 to 35 months of age at first calving,
20 to 55 months of age at second calving,
42 to 75 months of age at third calving,
classified within 365 days after calving,
at least one contemporary record in the herd-classification day-classifier-parity subclass,
 
The evaluation model for type trait is:
 
y = HCDP + A + P + SC + pe + u + e
 
where,
y:
classification records of type traits at first-third calving,
HCDP:
fixed effects of herd-classification day-classifier-parity,
A:
fixed effects of age in months at classification,
L:
fixed effects of the lactation stage at classification,
SC:
fixed effects of sire status of cow (national progeny-tested sire or not),
pe:
random effects of permanent environment effects,
u:
random effects of additive genetics,
e:
random residual.
 
 
Table: Heritabilities for type in Japan
Score type traits heritability
frame( include rump ) 0.32
overall feet & legs 0.11
dairy strength 0.31
overall udder 0.19
overall conformation( final score ) 0.24
Liner type traits heritability
1st calving
stature 0.51
chest width 0.26
body depth 0.35
angularity 0.20
BCS( body condition score ) 0.23
rump angle 0.42
rump width 0.41
rear leg side view 0.21
real leg rear view 0.12
foot angle 0.06
fore udder 0.22
rear udder height 0.27
rear udder width 0.21
udder supprt 0.20
udder depth 0.46
front teat placement 0.39
rear teat placement 0.33
teat length( front teat ) 0.41
 
 
Pedigree information on animals as well as random genetic group effects are considered in the same way as in production trait evaluations. And evaluations for score traits are expressed in EBV and SBV for bulls, however, those for linear traits are published only in SBV.