Table 3 Intraclass correlations for body weight, plasma creatine kinase activity, pH, tenderness, breast and thigh muscle colour at 8 weeks of age for 34 genetic lines of chickens calculated over all genetic lines (t_w) and within category (t_wb)

Weight and CK

Live weight, kg

0.96^§

0.68^§

3.67

1.01

1.06

0.168***

ln CK (iu/mL)

0.89^§

0.62^§

6.73 (835)

5.20 (181)

5.35 (211)

0.161***

Breast muscle pH and toughness

pHi

0.34^‡

0.35

6.09

6.16

6.16

0.017***

pHu

0.68^§

0.51^‡

5.69

5.87

5.81

0.034***

ΔpH

0.69^‡

0.33^‡

0.40

0.29

0.35

0.036**

Force N

0.58^‡

0.40†

31.1

36.1

35.5

1.04***

Breast muscle colour

Lightness (L*)

0.52^§

0.50^‡

55.0

53.6

53.5

0.83

Redness (a*)

0.49^‡

0.14

2.95

5.74

5.21

0.372***

Yellowness (b*)

0.72^§

0.35^‡

2.14

5.41

3.77

0.364***

Thigh muscle colour

Lightness (L*)

0.44^‡

0.45^‡

51.3

51.9

52.1

1.03

Redness (a*)

0.20†

0.20

6.55

6.24

7.03

0.541

Yellowness (b*)

0.62^§

0.32^‡

-1.34

1.45

0.92

0.411***