Table 3 Effects of L-Leu on ruminal free amino acid concentrations at 4 h post-feeding in beef cattle (n = 6)

Methionine

1.02

1.35

0.127

0.222

Threonine

3.40

5.09

0.462

0.058

Valine

3.18

3.53

0.232

0.495

Isoleucine

1.90

2.97

0.297

0.064

Leucine

3.45

3.22

0.468

0.831

Phenylalanine

2.42^a

3.64^b

0.279

0.011

Lysine

5.97^a

10.96^b

1.266

0.034

Total EAA

21.35

30.79

2.772

0.085

Asparagine

2.85

4.17

0.429

0.129

Cystine

0.92^a

0.55^b

0.084

0.010

Serine

2.11

2.61

0.197

0.234

Glutamine

15.46

20.95

2.354

0.275

Glycine

1.49

1.86

0.137

0.190

Alanine

5.11

5.82

0.400

0.414

Tyrosine

2.56^a

3.60^b

0.261

0.033

Histidine

0.05

0.17

0.032

0.066

Arginine

0.79

0.67

0.132

0.692

Total NEAA

31.36

40.43

3.790

0.261

Total BCAA

8.53

9.73

0.860

0.530

Total AA

52.71

71.22

6.479

0.167