Detailed Dairy Cattle Evaluation Information
2017/03/16
Genetic evaluation for herd life
Herd life is evaluated using a multiple trait animal model. Data contains herd life, first lactation milk and 6 liner type traits.

The evaluation model is :
y HL= HYT + A + pe + u + e
y Milk/SCS= HYT + BMY + A + u + e
y Type= HCD + A + L + u + e

where,
y HL :
herd life (obsebed herd life until 84-months of age),
y Milk/SCS :
305-d milk yield and average of somatic cell score at first calving,
y Type :
liner scores for 6 type traits ( overall feat and legs, chest width, angularity, udder support, udder depth and front teat placement),
HYT :
fixed effects of herd-year-milking frequency,
A :
fixed effects of calving age groups,
HCD :
fixed effects of herd-classifeir-classification day,
L :
fixed effects of lactation stage at classification,
u :
random effects of additive genetics,
e :
random residuals.

Heritability is 0.08.