Table 5 Free amino acid contents in serum of laying hens fed dietary citrulline at 42 weeks old

21.02 ± 1.05

21.84 ± 0.96

21.79 ± 0.85

22.24 ± 0.75

0.824

28.96 ± 2.07

35.04 ± 4.06

30.15 ± 5.44

36.73 ± 3.54

0.456

19.43 ± 0.73

23.36 ± 2.32

23.23 ± 2.14

24.53 ± 1.79

0.255

15.38 ± 1.14

15.69 ± 0.77

15.57 ± 0.80

16.19 ± 1.01

0.942

5.42 ± 0.30^b

4.90 ± 0.26^b

5.28 ± 0.53^b

7.67 ± 0.88^a

0.008

42.15 ± 3.90

45.88 ± 3.29

43.27 ± 1.27

46.97 ± 3.43

0.681

17.64 ± 1.09^c

19.36 ± 0.96^bc

22.53 ± 0.80^a

20.78 ± 1.20^ab

0.016

11.43 ± 0.61

13.34 ± 1.22

13.45 ± 0.93

13.84 ± 0.68

0.302

24.70 ± 1.04

27.61 ± 2.16

27.23 ± 1.50

26.20 ± 1.61

0.727

24.31 ± 0.73^a

18.20 ± 0.78^b

17.57 ± 1.26^b

19.41 ± 2.08^b

0.006

13.42 ± 1.48

16.19 ± 2.03

15.58 ± 1.44

16.53 ± 1.01

0.491

59.65 ± 4.72

63.90 ± 2.80

66.91 ± 4.00

66.53 ± 3.51

0.524

30.12 ± 2.51

29.11 ± 1.13

28.34 ± 0.91

26.91 ± 0.95

0.505

42.74 ± 2.50

39.78 ± 2.39

44.44 ± 3.09

40.04 ± 2.07

0.518

39.72 ± 2.50

42.18 ± 3.20

37.42 ± 1.62

40.14 ± 2.34

0.609

5.48 ± 0.80

4.46 ± 0.67

5.61 ± 0.99

5.09 ± 0.78

0.755

25.87 ± 1.42

27.86 ± 2.22

27.19 ± 1.62

25.91 ± 0.85

0.771

4.90 ± 0.51

4.51 ± 0.14

4.34 ± 0.46

5.65 ± 0.35

0.111

0.24 ± 0.02^b

0.26 ± 0.02^b

0.28 ± 0.03^b

0.57 ± 0.06^a

0.004

2.07 ± 0.15

1.72 ± 0.07

2.09 ± 0.13

1.54 ± 0.26

0.073

1.05 ± 0.08^ab

0.85 ± 0.04^b

1.15 ± 0.08^a

1.08 ± 0.07^a

0.032

7.20 ± 0.59

6.53 ± 0.78

5.53 ± 0.3

5.88 ± 0.55

0.217

2.06 ± 0.16

2.31 ± 0.08

2.24 ± 0.17

2.03 ± 0.20

0.556

2.46 ± 0.26

2.08 ± 0.19

2.20 ± 0.13

1.94 ± 0.11

0.241