Endogenous urinary metabolite excretion in the growing pig

Abstract

Endogenous urinary total nitrogen (N) and urea N excretions in the growing pig were measured using either the protein-free or regression method. Eighteen entire male pigs (28 kg liveweight) were randomly and equally allocated between six levels of feeding of a barley diet. Mean daily urinary total N and urea N excretions were determined. The regression of urinary metabolite output on dietary N intake extrapolated to zero N intake gave endogenous urinary total N and urea N excretions of 144.6 and 51.5 mg/kgo. 75 per day, respectively. Corresponding values for six of the pigs subsequently given a protein-free diet for 11 days, with endogenous excretions calculated over the final six days, were 163.3 and 62.2 mg/kgo. 75 per day. The urinary creatinine excretion of the barley-fed pigs was not related to dietary N intake. Mean daily urinary creatinine excretion was 53.1 ± 3.3 mg/kgo. 75 whereas that for pigs given the protein-free diet was 61.2 ± 2.0 mg/kgo. 75 • Although endogenous urinary metabolite losses tended to be higher for pigs on the protein-free feeding regime, endogenous urea N and creatinine N were close to 0.40 and 0.14 of endogenous total N respectively for pigs fed either the protein-free or barley diet.

Effect of feeding level on ileal and total tract digestibility of nutrients and energy from soybean meal‐based diets for piglets

“…According to Moughan et al. () and Otto et al. (), urinary endogenous N loss amounts to 0.14 g/kg BW 0.75 day in pigs of 28 kg BW fed a barley‐based diet and 2.4 g/day (equivalent to 0.14 g/kg BW 0.75 day) in grower pigs (initial BW 45 kg), which is in the range of values reported herein.…”

“…There exist, however, only few reports on urinary endogenous N loss in pigs, and studies with piglets are still missing. As in the present study total N intake and urinary N loss increased linearly (p < 0.05) with increasing FI level (Table ), estimates of urinary endogenous N loss can be obtained by linear regression analysis (Moughan et al., ). These estimates of urinary endogenous N loss ranged from 0.07 to 0.85 g/kg BW 0.75 day (lower and upper limit of the 95% confidence interval, respectively).…”

“…() and Moughan et al. () a large variability in urinary endogenous N loss between animals, and may explain, at least in part, why the effect of FI level on N disappearance in the large intestine was not reflected in urinary N loss.…”

An Evaluation with Piglets of Bovine Milk, Hydrolyzed Bovine Milk, and Isolated Soybean Proteins Included in Infant Milk Formulas. I. Effect on Organ Development, Digestive Enzyme Activities, and Amino Acid Digestibility

“…(25) for young piglets kept in specialized metabolism cages, indicating that collection of urine was complete. The absolute rates of urinary urea and total nitrogen excretion were very low and sometimes lower than values reported (26) for endogenous excretion in the 3O-kg live-weight pig (110 and 145 mg/kgo. 75/day, respectively).…”

Nitrogen excretion in rats on a protein-free diet and during starvation

“…Considering that the amount of faeces voided during starvation was negligible, it can be assumed that the UN represents the total endogenous N. Rats fed the protein free diet had almost the same total excretion of endogenous N during feeding and starvation (165 and 157 mg/kg W 0.75 ). The values correspond to 128 mg/kg W 0.75 for rats (Yokogoshi et al 1977) and 163 mg/kg W 0.75 for pigs (Moughan et al 1987), using protein-free diets. While the UN of 445 mg/kg W 0.75 from the protein group corresponds well to 430 mg/kg W 0.75 previously measured in young growing rats fed protein adequate diet and then starved for three days (Chwalibog et al 2005).…”