Somatic cell score is evaluated using a log transformation data, The records have been accumulated by the DHIP.
Table: The relation between count and transformed score of somatic cell count
somatic cell count
(/1ml) |
transformed
score |
| 12,500 |
0.00 |
| 25,000 |
1.00 |
| 50,000 |
2.00 |
| 100,000 |
3.00 |
| 200,000 |
4.00 |
| 400,000 |
5.00 |
| 800,000 |
6.00 |
| 1,600,000 |
7.00 |
| 3,200,000 |
8.00 |
| 6,400,000 |
9.00 |
| 12,800,000 |
10.00 |
The evaluation model is :
y = HTDT + A + pe + u + at + b × exp (-0.05t) + e
where,
y :
somatic cell score of first calving on test day,
HTDT :
fixed effects of herd-test day - milking frequency,
A :
fixed effects of calving age groups,
pe :
random effects of permanent environment,
t :
days in milk,
u :
random effects of additive genetics,
a and b :
coefficients of Willmink's curves,
e :
random residuals.
Heritability is 0.082.
For the development of the livestock industry and a healthy diet in Japan
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