Table 1
Data structure, arithmetic means and standard deviation (in brackets)

Observations (n)	1,078,966
Herds (n)	268
Sires (n)	1,930
Dams (n)	107,372
Cows (n)	146,765
SCS (units)	2.433 (1.149)
Milk yield (kg)	32.82 (7.36)
Fat yield (kg)	1.075 (0.333)
Protein yield (kg)	1.006 (0.239)
Days in milk	151.36 (83.30)
CGa	15,517