M. Szanyiova et al., PARTITION OF NITROGENOUS SUBSTANCES IN THE URINE OF SHEEP ON DIFFERENT DIETARY-PROTEIN INTAKES, Veterinary research, 26(1), 1995, pp. 27-31
The distribution of nitrogenous substances in urine was studied in she
ep fed high (28.71 g N daily) and low (9.32 g N daily) protein diets f
or 6-8 weeks. The concentrations of total nitrogen and urea, allantoin
, free amino acids, uric acid, hippuric acid, creatinine, creatine and
ammonia were measured in urine. The nitrogen content of these measure
d substances was calculated. The results showed that the concentration
s of total urinary nitrogen and nitrogen of individual nitrogenous sub
stances were lower in sheep on a low protein diet, except for uric aci
d nitrogen which was unchanged. Urea nitrogen was responsible for up t
o 74% of the total urinary nitrogen of both groups of animals without
any significant difference. The individual nitrogen portions of nitrog
enous substances other than urea in total urinary-N did not exceed 7%
during the intake of both diets. The intake of a low protein diet resu
lted in a significant increase in the proportion of nitrogen from uric
acid, hippuric acid, creatinine and free amino acids, while the fract
ion of ammonia nitrogen in the total urinary N was significantly reduc
ed. It is concluded that different protein or nitrogen intake in the d
iet do not have any significant effect on the urea nitrogen fraction i
n the total urinary nitrogen of sheep.