Animais offered GS-based diets had greater urinary creatinine
excretion (P < 0.01) when compared with animals offered
CS-based diets. Urinary creatinine N excretion
was greater from animals offered G− than from those
offered C− (P = 0.04) and C+ (P < 0.01) but not
G+ (P = 0.25); G+, C−, and C+ were not different
(P > 0.05). Allantoin N and the ratio of allantoin N
to creatinine N were not affected by dietary treatment
(P > 0.05). Rumen fluid NH3-N (mg/L) was higher
for animals offered GS-based diets (P = 0.01) than for
those offered CS-based diets.
Urea N (g/d) = 11.26 (±7.39) + 59.87 (±16.61)
× feed N (kg/d). [1]