Table 6 Descriptive statistics of the phenotypic values for milk production traits

Lactation

1

2

1

2

1

2

1

2

1

2

Milk yield, kg

8140.13

9735.07

1467.72

1750.93

12536.44

15016.28

3721.48

4335.76

0.18

0.18

Fat yield, kg

304.08

367.27

72.29

97.83

562.43

676.50

98.57

153.94

0.24

0.27

Fat percentage, %

3.77

3.79

0.76

0.84

6.97

6.61

2.00

2.01

0.20

0.22

Protein yield, kg

257.06

309.70

46.03

55.87

398.19

466.83

114.16

154.87

0.18

0.18

Protein percentage, %

3.17

3.20

0.26

0.29

4.01

4.06

2.34

2.33

0.08

0.09