Temperament
and milking speed are evaluated
by sire-maternal grandsire (MGS)
threshold models. Temperament
and milking speed of cows are
classified into two
(temperament: moderate or rough)
or three (milking speed: slow,
normal or fast) categories.
Temperament and milking speed
data have been collected through
the type classification program.
Sire evaluations for temperament
and milking speed are expressed
in relative ETA with average of
100 and standard deviation of
1.
These
data editing criteria for
temperament and milking speed
evaluations are the same as
required for type trait
evaluation. Data editing
criteria are :
holstein,
sire
is known,
18
to 35 months of age at first
calving,
tested
within 365days after
calving,
at
least one contemporary record in
the herd - classification day -
classifer
subclass.
The
evaluation model for temperament
and milking speed
is:
y =
hcd + A + L + s + 1/2mgs +
e
where,
y:
records
of temperament and milking speed
assumed normally
distributed,
hcd:
random
effects of
herd-classifier-classification
day,
A:
fixed
effects of age at classification
(18-25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38-39,
40- months old)
L:
fixed
effects of the lactation stage
at classification (-30, 31-60,
61-90, 91-120, 121-150, 151-180,
181-210, 211-240, 241-270,
271-300, 301-330, 331-365 days
in milk)
s,mgs:
random
additive genetic effects of the
sire or maternal
grandsire,
e:
random
residuals.
In
temperament and milking speed
evaluations, pedigree
information among bulls is used,
and sire and MGS of bulls within
four generations of recorded
cows are
identified.
Helitability
of temperament and milking speed
are 0.08 and 0.11.
For
the
development
of
the
livestock
industry
and
a
healthy
diet
in
Japan
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