Purine derivatives excretion in lactating ewes fed straw diets with different levels of fish meal

Martín‐Orúe, S. M.; Dapoza, C.; Balcells, J.; Castríllo, C.

doi:10.1016/s0377-8401(96)01022-x

Cited by 12 publications

(13 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Allantoin was the predominant PD in milk, but the contribution of uric acid was much higher than in urine, accounting for 0.358 ± 0.023 of total milk PD, independently of the duodenal supply of PB. The high proportion of uric acid in milk compared to urine confirms previous results in milking cows (Giesecke et al, 1994;Gonda and Lindberg, 1997) and ewes (Martín-Orú e et al, 1996), but unlike ewes' milk (Martín-Orú e et al, 1996), no significant amounts of xanthine or hypoxanthine (less than 2 μmol/L) were detected in cows' milk. Therefore, allantoin plus uric acid accounted for the total PD.…”

Section: Purine Derivative Excretion In Relation To Purine Bases Supplysupporting

confidence: 88%

“…Incomplete urinary recovery of absorbed purine bases (PB) has been reported (Chen et al, 1990b;Balcells et al, 1991); saliva (Chen et al, 1991;Surra et al, 1997) and milk (Giesecke et al, 1994;Martín-Orú e et al, 1996) are the proposed nonrenal routes of PD excretion. In dairy cows, the input/output relationship between duodenal and urinary purines may be modified if the excretion rate of PD throughout the mammary gland is altered by unidentified factors.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Purine Derivative Excretion in Dairy Cows: Endogenous Excretion and the Effect of Exogenous Nucleic Acid Supply

González-Ronquillo

Balcells

Guada

et al. 2003

Journal of Dairy Science

Self Cite

View full text Add to dashboard Cite

An experiment was conducted with dairy cows to study the partitioning of excreted purine derivatives between urine and milk and to quantify the endogenous contribution following the isotopic labeling of microbial purine bases. Three lactating cows in their second lactation that had been cannulated in the rumen and the duodenum were fed a mixed diet (48:52, roughage/concentrate ratio) distributed in equal fractions every 2 h, and duodenal flow of purine bases was determined by the dual-phase marker system. Nitrogen-15 was infused continuously into the rumen to label microbial purine bases, and the endogenous fraction was determined from the isotopic dilution in urinary purine derivatives. Urinary and milk recovery of duodenal purine bases were estimated at early (wk 10) and late (wk 33) lactation by the duodenal infusion of incremental doses (75 and 150 mmol purine bases/d) of RNA from Torula yeast. Each period was 6 d, with RNA being infused during the last 4 d, followed by measurement of the flow of purine bases to the duodenum. The isotope dilution of purine derivatives in urine samples confirmed the presence of an endogenous fraction (512 +/- 36.43 micromol/W0.75 or 56.86 mmol/d) amounting to 26 +/- 3.8% of total renal excretion. Total excretion of purine derivatives in urine plus milk was linearly related to the duodenal input of purine bases, but the slopes differed (P < 0.005) between lactation stages resulting in a lower equimolar recovery in early (y = 58.86 (+/-3.89) +0.56 (+/-0.0164) x; r = 0.90) than late lactation (y = 58.86 (+/-3.89) + 0.70 (+/-0.046) x; r = 0.80). Excretion of purine derivatives through milk represented a minimum fraction of total excretion but responded significantly to the duodenal input of purine bases. No differences between lactation stages were detected, and variations in milk yield did modify significantly the amount of purine derivatives excreted through the milk.

show abstract

Section: Purine Derivative Excretion In Relation To Purine Bases Supplysupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Purine Derivative Excretion in Dairy Cows: Endogenous Excretion and the Effect of Exogenous Nucleic Acid Supply

González-Ronquillo

Balcells

Guada

et al. 2003

Journal of Dairy Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…0.371 or 315 mmol/kg LW 0.75 s.e. 0.016) were similar to those reported in lactating Rasa Aragonesa ewes (Martín-Orúe et al 1996;Dapoza et al 1999).…”

Section: Urinary Excretion Of Creatininesupporting

confidence: 87%

Effects of crude protein level in the concentrate and time allotment on pasture on milk yield, urinary nitrogen, and purine derivative excretion in lactating Latxa ewes

et al. 2015

Self Cite

View full text Add to dashboard Cite

This study assessed the influence of reducing the crude protein (CP) content (from 190 to 130 g/kg CP/kg) in the supplementary concentrate and time allotment on pasture (TAP) on the milk yield, bodyweight, and the urinary nitrogen (N) and purine derivatives (PD) in lactating Latxa ewes. Animals were reared in a production system that restricted the amount of time that ewes spent on pasture. In mid-April, at the start of the 42 days experiment, 40 dairy Latxa ewes were assigned to one of four groups on the basis of their initial milk yield, days in lactation (DIL), bodyweight (BW), and condition score; thereafter, each group grazed in its own fenced paddock. The experiment was based on a 2 × 2 factorial design that included two CP levels and two pasture grazing regimes: 4 h continuous grazing (CG) in the morning or 2 h grazing in the morning and 2 h in the afternoon (DG). Individual milk yield was recorded three times a week, and time spent grazing and BW was recorded weekly. In the middle (day 15–17; P1) and at the end (day 36–38; P2) of the experiment, urinary spot samples were collected using a catheter. At the end of the experiment, ewes were confined to metabolic cages and urine was collected. CP level of the concentrate was not correlated with time spent grazing; however, the ewes that were permitted access to pasture twice per day spent more time grazing (223 min/day vs 207 min/day, P < 0.01) and were more efficient with their time (56 min/h grazing vs 52 min/h, P < 0.05) than the ewes that were permitted access to pasture once per day. Concentrate CP levels were not correlated with milk yield or composition, although ewes that received the high protein (HP) lost more weight than did those that received the low protein (LP) concentrate. Concentrate CP level and TAP were not correlated with creatinine (CR) excretion rate (mean = 315 µmol/kg LW0.75 s.e. 0.0161). Urea-N was the largest component of urinary-N (68.7 s.e. 2.33%; P > 0.05), and urea-N waste was higher in HP ewes (202.7 mmol/day) than it was in LP ewes (159.5 mmol/day) (s.d. 27.83; P < 0.01). Ewes subjected to the DG regime had significantly (P < 0.01) higher urinary PD excretion (23.6 vs 21.4 mmol/day s.d. 4.01; P < 0.01), and tended (P < 0.1) to excrete less urea-N (175.1 vs 188.3 mmol, s.d. 27.83) than did the CG ewes. A reduction in the CP in the supplementary concentrate led to a reduction in N waste without having a detrimental effect on performance or milk production.

show abstract

“…The amount of allantoin secreted into milk is 0.6–3% of urinary excretion (Shingfield 2000), and that of uric acid is 3% and 17% in cattle (Valadares et al . 1999) and sheep (Martin‐Orue et al . 1996), respectively.…”

Section: Purine Metabolism and Microbial Protein Supplymentioning

confidence: 99%

“…Some work has been done using milk allantoin based on a relationship between renal and mammary allantoin excretion. In sheep and cattle there is no significant relationship between milk and urinary allantoin or PD excretion (Martin‐Orue et al . 1996; Gonda & Lindberg 1997).…”

Section: Pd Excretion and Estimation Of Microbial Protein Synthesismentioning

confidence: 99%

Metabolism of microbial nitrogen in ruminants with special reference to nucleic acids

Fujihara¹,

Shem²

2011

Animal Science Journal

View full text Add to dashboard Cite

Characteristically the metabolism of microbial nitrogen (N) compounds in ruminants involves the degradation of dietary N and synthesis of microbial protein (MP), compounds including a small amount of peptides and free amino acids, which may account for 75-85% of total N and the remainder are nucleic acids (NA: DNA and RNA). Generally rumen microbes contain 10-25% NA-N of the total N while 70-80% is in the form of RNA. This paper describes the degradation and synthesis of NA in the rumen and their fate in the lower digestive tracts. Their physiological and nutritional significance in different types of ruminant animals is also discussed. The research works on NA metabolism in ruminants has been mainly on metabolism of purines after rumen microbial digestion and absorption in the lower gut. Subsequently, the fate of absorbed purines has been intensively investigated to assess the extent of MP synthesis in the rumen. The method for predicting ruminal synthesized MP and subsequently digested MP has been proposed using urinary purine derivative (PD) excretion in sheep and cattle fed on ordinary feed. The latter approach has now been adopted for calculation of protein supply in some feeding standards, although there are still difficulties in predicting representative samples of rumen microbes, and also uncertainties in variations of non-renal and endogenous purine losses.

show abstract

Purine derivatives excretion in lactating ewes fed straw diets with different levels of fish meal

Cited by 12 publications

References 10 publications

Purine Derivative Excretion in Dairy Cows: Endogenous Excretion and the Effect of Exogenous Nucleic Acid Supply

Purine Derivative Excretion in Dairy Cows: Endogenous Excretion and the Effect of Exogenous Nucleic Acid Supply

Effects of crude protein level in the concentrate and time allotment on pasture on milk yield, urinary nitrogen, and purine derivative excretion in lactating Latxa ewes

Metabolism of microbial nitrogen in ruminants with special reference to nucleic acids

Contact Info

Product

Resources

About