Table 3

Mean plasma concentration and urinary excretion of urea nitrogen and 3-methylhistidine (3-MH) in calves on the final day of a five day intravenous infusion of saline (control); glucose; essential amino acids (EAA) and glucose + EAA.


Control
Glucose
EAA
EAA+Glucose

Plasma Urea N mmol/L
8.8a ± 0.91
5.8b ± 0.37
11.0c ± 0.79
6.7ab ± 0.51
Plasma 3-MH μmol/L
3.3a ± 0.36
1.6b ± 0.24
1.9b ± 0.61
1.9b ± 0.13
Urinary Urea N g/d
16.8a ± 1.06
12.4b ± 1.19
25.3c ± 3.70
15.8ab ± 1.71
Urinary 3-MH:Creatinine mg/g
13.3a ± 0.51
12.2b ± 0.33
12.5a ± 0.24
12.2a ± 0.22
Net Nitrogen Balance g/kg/d
0.52
0.80
1.06
1.66

Values are averages of 6 blood samples taken at hourly intervals during the last 6 hours of the infusion or pooled urine collected over the last 4 days of infusion. Net nitrogen balance is the difference between digested nitrogen intake (assuming a nitrogen digestibility of 0.85) and urinary nitrogen excretion. Values are means ± standard error of the mean (SEM). a,b,c Values within the same row with different superscripts are significantly different (P < 0.05).

Sadiq et al. Nutrition & Metabolism 2008 5:5   doi:10.1186/1743-7075-5-5