Table 5 Effects of supplementation with protein in different sites on the characteristics of nitrogen utilization in the animals in cattle fed tropical forage

SUN, mg/dL

7.29^c

17.16^a

13.46^ab

13.39^b

1.30

0.029

BAA, μmol/mg creatinine

113

123

129

119

12

0.485

Nitrogen intake, g/d

64.5^b

103.8^a

97.8^a

98.0^a

6.4

<0.001

Fecal nitrogen, g/d

34.0

36.0

35.5

33.4

4.0

0.611

Urinary nitrogen, g/d

26.3^b

48.5^a

40.4^a

46.3^a

4.2

0.010

Nitrogen balance, g/d

4.1^b

19.3^a

22.0^a

18.3^a

6.6

0.062

NBR, g/d

−14.4^c

12.2^a

−23.2^c

−2.0^b

7.5

0.005

ENU

g retained nitrogen/g of ingested nitrogen

0.04

0.18

0.22

0.18

0.05

0.165

g retained nitrogen /g of nitrogen absorbed in the intestines

0.07

0.27

0.35

0.27

0.04

0.402

PDI, g/d

280^c

347^bc

535^a

416^b

45

0.003

3-MH, mg/g of creatinine

50.8^a

20.6^b

29.6^b

31.0^b

13.1

0.077

UEUN, g/d

13.4^b

28.9^a

25.9ª

30.1^a

2.9

0.002

UFK, g/d

42.9 ± 6.5^b

60.9 ± 5.6^a

43.9 ± 5.6^b

55.0 ± 5.6^a

---

0.062

FUEUN, g/g

0.35 ± 0.09

0.48 ± 0.08

0.63 ± 0.08

0.55 ± 0.08

---

0.121

NMIC, g/d

53.1 ± 13.0

61.2 ± 11.1

61.9 ± 13.0

58.8 ± 11.1

---

0.932