Indeed, the main part of
urinary nitrogen is lost as urea which is rapidly converted to ammonia when exposed to fecal urease.
The results obtained in this study are in agreement with this statement, since the treatment without urea promoted lower nitrogen excretion via urine, while the other treatments promoted the linear excretion of
urinary nitrogen, according to the inclusion of urea in the diet.
It ultimately minimizes losses of protein in form of methane and
urinary nitrogen. Tannins may improve protein utilization in ruminants (Mueller-Harvey, 2006).
Table 3: Nitrogen intake, fecal nitrogen,
urinary nitrogen and nitrogen balance in growing Kajli lambs fed different dietary rumen undegradable protein (RUP) levels
Using more protein supplements than necessary also increases
urinary nitrogen, often leading to additional nitrogen runoff that pollutes waterways, says Glen Broderick, a former ARS dairy scientist with the U.S.
Intake nitrogen, fecal nitrogen and
urinary nitrogen were analysed for total nitrogen by Kjedahl method, and nitrogen balance and nitrogen retention were calculated according to the following formulas:
The serum levels of plasma creatinine concentration, blood
urinary nitrogen, total plasma cholesterol, plasma triglyceride were measured using a multichannel analyzer (Roche Hitachi 737; Boehringer Mannheim Diagnostics, USA).
The total nitrogen intake,
urinary nitrogen and nitrogen retention were similar among the frequencies.
The original purpose of the OPEN study, completed in 2000, was to assess self-reported dietary measurement error by comparing results from self-reported dietary intake questionnaires with objective biomarkers: doubly labeled water and
urinary nitrogen.
From Week 2 to Week 3, shifts to more positive nitrogen balances occurred due to decreases in
urinary nitrogen excretion.
The measurement of VO2, which is the equivalent of metabolic rate, and VCO2, as well as the measurement of
urinary nitrogen (UN), can be used to determine the resting energy expenditure (REE).
(a) Models Predictors P R2 UFF GC3 3.3 0.078 0.11
Urinary nitrogen 0.05 0.006 0.36 0.47 UFF + UFE GC3 15.5 0.001 0.21
Urinary nitrogen 0.11 0.003 0.29 Plasma leptin -7.3 0.001 0.22 5a-THF/THF -35.7 0.057 0.09 0.72 (b) (a) Stepwise multiple regression results (models a priori adjusted for GC3).