Detailed Dairy Cattle Evaluation Information
2021/02/16
Genetic evaluation for female fertility traits
The female fertility traits are evaluated using a multiple trait animal model. Data contains maiden heifer conception rate at first insemination, cow conception rate at first insemination after first calving and days open after first calving. First insemination year is since 1990, and data editing criteria is :

holstein,
sire known,
insemination date known,
first insemination is not ET,
Allowed range of first insemination are 8-26 at heifer and 20-46 at first lactation,
days from calving to first insemination is within 365 days,
at least one contemporary record in the herd-year at first insemination subclass.

The evaluation model for female fertility traits is:

yCR0 /CR1 /DO =FHY +FM +FA +s +u +e

where,
yCR0/CR1/DO :
maiden heifer conception rate, cow conception rate after first calving and days open after first calving (max 365 days),
FHY :
fixed effects of herd-year at first insemination,
FM :
fixed effects of month at first insemination,
FA :
fixed effects of age at first insemination,
s :
random effects of service sire,
u :
random effects of additive genetics,
e :
random residual.


Table: Heritabilities for female fertility traits
Traits heritability
Maiden heifer conception rate 0.016
Cow conception rate after first calving 0.020
Days open after first calving 0.053