EurekaMag.com logo
+ Site Statistics
References:
54,215,046
Abstracts:
30,230,908
PMIDs:
28,215,208
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on LinkedInFollow on LinkedIn

+ Translate

Excretion of purine derivatives by ruminants: effect of exogenous nucleic acid supply on purine derivative excretion by sheep



Excretion of purine derivatives by ruminants: effect of exogenous nucleic acid supply on purine derivative excretion by sheep



British Journal of Nutrition 63(1): 131-142



The present study examined the relationship between the supply of exogenous nucleic acid (NA) purines and their recovery as the derivatives hypoxanthine, xanthine, uric acid and allantoin in urine. Six lambs, totally nourished by intragastric infusions of volatile fatty acids (VFA) and casein (i.e. no rumen fermentation), were given by abomasal infusion a microbial NA concentrate at six levels (from zero to 24-5 mmol purines/d). The true digestibility between the abomasum and terminal ileum of the NA purines was measured in a separate experiment using three lambs. The relative proportion of urinary allantoin increased, and that of other derivatives decreased, as the amount of NA infused was increased. The relationship between total excretion of purine derivatives (Y; mmol/d) and exogenous purines absorbed (X; mmol/d) was Y = 0.84 X + 0.150W0.75e-0.25X, where W is body-weight (kg). This implies that the endogenous contribution to the total excretion of derivative decreased as the supply of exogenous purines increased, with an associated progressive replacement of de novo synthesis by exogenous purines. The model also implies that 0.16 of the purines were eliminated through routes other than derivative excretion in urine. Once excretion exceeded 0.6 mmol/kg W0.75 per d, endogenous excretion was effectively zero and thus Y = 0.84 X. In normally fed sheep, derivative excretion should therefore relate to the microbial purines and, hence, microbial protein absorbed according to these models. The changing proportions of allantoin and other derivatives in urine were probably due to changes in the relative importance of endogenous and exogenous purines as precursors.

(PDF emailed within 0-6 h: $19.90)

Accession: 001831133

Download citation: RISBibTeXText

PMID: 2317474

DOI: 10.1079/bjn19900098



Related references

Excretion of purine derivatives by ruminants effect of microbial nucleic acid infusion on purine derivative excretion by steers. Journal of Agricultural Science 114(3): 243-248, 1990

Purine derivative excretion in dairy cows: endogenous excretion and the effect of exogenous nucleic acid supply. Journal of Dairy Science 86(4): 1282-1291, 2003

The effect of exogenous purine supply on the endogenous excretion of purine derivatives in the urine of growing lambs. Animal Science Journal 77(6): 582-586, 2006

The effect of exogenous purine supply on plasma concentration and urinary excretion of purine derivatives in growing goat kids. Progress in research on energy and protein metabolism International Symposium, Rostock Warnemunde, Germany, 13-18 September, 2003: 765-768, 2003

Excretion of purine derivatives by ruminants: endogenous excretion, differences between cattle and sheep. British Journal of Nutrition 63(1): 121-129, 1990

Effect of purine nucleoside supply on urinary excretion of purine derivatives in growing kids. Nunes, A F, Portugal, A V, Costa, J P, Ribeiro, J R EAAP Publication; Protein metabolism and nutrition 229, 1996

Effect of level of feed intake on the excretion of purine derivatives and purine derivatives to creatinine ratio in the urine of sheep. Asian-Australasian Journal of Animal Sciences 5(3): 465-468, 1992

Excretion of endogenous and exogenous purine derivatives in sheep: effect of increased concentrate intake. British Journal of Nutrition 79(3): 237-240, 1998

The effect of feed intake and body weight on purine derivative excretion and microbial protein supply in sheep. Journal of Animal Science 70(5): 1534-1542, 1992

Supplementation of barley straw with starch Effect on microbial protein supply estimated from purine derivative excretion of sheep. Animal Production 56(3): 464, 1993

Excretion of purine derivatives in cows: Endogenous contribution and recovery of exogenous purine bases. Livestock Production Science 68(2-3): 243-250, March, 2001

The effect of supplementing straw with barley or unmolassed sugarbeet pulp on microbial protein supply in sheep estimated from urinary purine derivative excretion. Animal Production 55(3): 413-417, 1992

Estimation of microbial protein flow from the rumen of sheep using microbial nucleic acid and urinary excretion of purine derivatives. Canadian Journal of Animal Science 72(4): 821-830, 1992

The effect of protein infusion on urinary excretion of purine derivatives in ruminants nourished by intragastric nutrition. Journal of Agricultural Science 109(1): 7-12, 1987

Effect of fluctuating supply of purine nucleosides on the plasma and urinary purine derivatives in sheep nourished by intragastric nutrition. Journal of Dairy Science 77(SUPPL 1): 246, 1994