• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.465-468
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• 1992

Urinary purine derivatives and creatinine excretion was measured in a total of 4 white Alpine sheep. They were given diets 718 to 1060 g/kg dry matter (DM) of roughage. The crude protein content of this diets was on average $93.87{\pm}5.57g$ in kg DM. Purine derivatives-N excretion increased linearly with incremental DM intake and was significantly correlated (n = 16) with amounts of digestible organic matter (DOM) intake: allantoin-N (mg) = 1.205 (${\pm}0.070$) $\times$ DOM (g) - 136.709 (${\pm}37.399$), r = 0.9770, RSD = 22.97; uricacid-N (mg) = 0.131 (${\pm}0.041$) $\times$ DOM (g) + 11.380 (${\pm}21.881$), r = 0.6306, RSD = 13.44; Hypoxanthine-N (mg) = 0.049 (${\pm}0.014$) $\times$ DOM (g) - 28.640 (${\pm}7.708$), r = 0.6544, RSD = 4.73; total purine derivatives-N (mg) = 1.385 (${\pm}0.083$) $\times$ DOM (g) - 90.261 (${\pm}44.552$), r = 0.9706, RSD = 27.47. Microbial protein synthesis per kg DOM was estimated of 113 g. The urinary creatinine-N excretion was on average 9.10 mg/kg live weight (LW) with a standard error of 0.12 mg creatinine-N per kg LW. The excretion of creatinine excreton was not related to feed intake. Daily creatinine excretion (mg/d) was calculated from individual LW measurements and the average creatinine excretion (mg/kg LW). It was possible to predict the daily urinary purine derivatives excretion (r = 0.9720 for allantoin, r = 0.9886 for total purine derivatives) from the ratio of purine derivatives (mg/100 ml) and creatinine (mg/100 ml) in the urine and the daily creatinine excretion.

• Asian-Australasian Journal of Animal Sciences
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• 제19권3호
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• pp.347-355
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• 2006

A study was conducted to predict the rumen microbial protein production based on urinary excretion of purine derivatives in buffaloes fed a diet of wheat straw and concentrate (40:60) at four fixed levels of feed intake. (95, 80, 60 and 40% of preliminary voluntary feed intake) following experimental protocol of IAEA (Phase I). The buffaloes were allocated according to a $4{\times}4$ latin square design. The urinary allantoin, uric acid, total PD excretion (mmol/d) in treatments L-95, L-80, L-60 and L-40 was 20.13, 16.00, 12.96 and 9.17; 1.88, 2.12, 2.11 and 2.15; 22.01, 18.12, 15.07 and 11.32, respectively and were significantly (p<0.05) different among treatments except for uric acid. The rate of PD excretion (mmol/d) was positively correlated with the digestible organic matter intake. Variations were observed in PD and creatinine concentration in spot samples collected at 6-hour interval. However, daily PD:Creatinine ratio (PDC index) appears to be a reasonably good predictor of microbial-N supply. The contribution of basal purine excretion to total excretion of purine derivatives (PD) was determined in pre-fasting period followed by a fasting period of 6 d (Phase II). Daily PD and creatinine excretion (mmol/kg $W^{0.75}$) during fasting averaged 0.117 and 0.456 respectively for buffaloes. The excretion rates of PD decreased significantly (p<0.01) during fasting compare to pre-fasting period, the urinary creatinine excretion remained almost similar. Except for creatinine, plasma concentration of target parameters significantly (p<0.01) declined during fasting. Likewise, glomerular filtration rate (GFR) and renal clearance of allantoin and uric acid also decreased. Based on the PD excretion rates during fasting and at different levels of feed intake obtained in this study, a relationship between daily urinary PD excretion (Y-mmol) and microbial purine absorption (X-mmol) was developed for buffaloes as Y = 0.74X+0.117 kg $W^{0.75}$. The microbial N supply (g/kg DOMI) remained statistically similar irrespective of dietary treatment. The results showed that excretion of urinary purine derivatives is positively correlated with the levels of feed intake in Murrah buffaloes and thus, estimation of urinary purine derivatives and PDC index could be used to determine microbial nitrogen supply when there is large variation in level of feed intake.

• Asian-Australasian Journal of Animal Sciences
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• 제11권3호
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• pp.209-216
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• 1998

The paper presented here is aimed at increasing knowledge on purine metabolism in ruminants and hence the quantification of microbial cells entering the small intestine from urinaη excretion of purine derivatives. Nucleic acid metabolisms of micro-organisms in the rumen, digestion and absorption of nucleic acids entering the intestines, metabolisms of absorbed and endogenous purines involving de novo synthesis of nucleic acids in the ruminants host, and the relationship between absorbed and excreted purines are reviewed. Principal concerns about an amount of purine derivatives excreted in urine in relation to a change in purine-N: total-N ratios in rumen microbes that leave the rumen are discussed. The use of urinary excretion of purine derivatives as an indicator of the amount of microbial biomass leaving the rumen has to be done with some caution since it may be impossible to get a representative sample of microbes entering the intestine and thus yield estimates are relative rather than absolute.

• Asian-Australasian Journal of Animal Sciences
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• 제20권10호
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• pp.1567-1574
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• 2007

A study was carried out to study the response of total purine derivatives (PD) excretion in urine to determine microbial N (MN) supply at four fixed levels of feed intake (namely 95, 80, 60 and 40% of voluntary intake). The crossbred (CB) calves were allocated according to a $4{\times}4$ Latin Square Design and fed wheat straw and concentrate (1:1). The rate of PD excretion (mmol/d) as a linear function of feed intake was 15.85/kg DMI and 20.12/kg DOMI. Based on the endogenous and PD excretion rates obtained in this study, a relationship between daily urinary PD excretion (Y, mmol) and daily microbial protein supply (X, mmol) was developed for crossbred calves as Y = 0.83X+0.296 kg $W^{0.75}$. The derived microbial N values using this equation differed (p<0.001) among the 4 groups and was the highest in L-95 followed by L-80, L-60 and L-40. The relationship between urinary nitrogen loss (Y, g/d) and DOMI (X, kg/d) was established as: Y = 6.038X+21.753 ($r^2$ = 0.663, p<0.01). When urinary excretion of PD (Y, mmol/d) was plotted against intake of DM and DOM (X, kg/d), the equations obtained were: Y = 7.1711X+8.674 ($r^2$ = 0.889, p<0.01) and Y = 12.434X+7.683 ($r^2$ = 0.896, p<0.01), respectively. The proportional contribution of allantoin and uric acid to total PD remained stable irrespective of level of feed intake. Similarly, urinary excretion of creatinine did not differ (p>0.05) between animals fed at different levels. The MN supply was the highest to animals at intake levels L-95, and decreased linearly with corresponding decrease in feed intake. However, the MN supply when expressed per kg DOMI remained statistically (p>0.05) similar irrespective of level of intake. The results revealed that the excretion of urinary purine derivatives were positively correlated with the level of feed intake as well as rumen microbial supply and thus it could be a good indicator for measuring the microbial protein supply and nutritional status of animals.

• Asian-Australasian Journal of Animal Sciences
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• 제20권8호
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• pp.1201-1207
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• 2007

This study compared the recovery rate of intrajugular-administered allantoin in the urine and saliva between swamp buffaloes and zebu cattle to examine whether it could explain the lower excretion rate of urinary purine derivatives (PD) in the buffaloes. Three male swamp buffalo yearlings, with an average body weight of $349{\pm}40.35$ kg, and three Thai native cattle ($154{\pm}3.26$ kg) of similar age and sex were used in the study. Animals were kept in individual pens and fed at a maintenance energy level with a diet containing 65% monk bean husk (Vigna radiata) as roughage and 35% concentrates. Allantoin solution was infused into the jugular vein in four incremental rates equivalent to 0, 5, 10 and 15 mmol/d and urine was collected daily in acidified form. Daily PD excretion was linearly correlated with intrajugular allantoin infusion in both species. The relationship between daily urinary PD excretion (Y, mmol/d) and intrajugular allantoin infused (X, mmol/d) was $Y=0.75{\pm}0.318X+22.45{\pm}2.98$ ($r^2$ = 0.36, n = 12, MSE = 38.02, CV = 21.9, p<0.01) for swamp buffaloes and $Y=0.96{\pm}0.10X+15.93{\pm}0.92$ ($r^2$ = 0.91, n = 12, MSE = 3.60, CV = 8.27, p<0.01) for zebu cattle. The salivary PD concentration was not correlated with intrajugular allantoin infusion in both species, with values for buffaloes numerically lower than those for cattle. The present study reconfirmed previous studies that buffaloes have a lower plasma PD excretion rate via the renal route and a significant proportion (22%) of the plasma PD loss is via the saliva. However, results of our present and previous studies suggest that differences in purine base (PB) metabolism between buffaloes and zebu cattle occur before the purine compounds reach the plasma pool.

• Asian-Australasian Journal of Animal Sciences
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• 제19권9호
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• pp.1291-1297
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• 2006

The potential of the spot urine sampling technique as an alternative to performing a total urine collection to predict the microbial nitrogen supply was evaluated in crossbred bulls. In a completely randomized design, 20 growing crossbred bulls were assigned four levels of feed intake (120, 100, 80 and 60% of voluntary dry matter intake) on diets comprised of wheat straw and concentrate mixture (50:50). After three months of experimental feeding, a metabolism trial was conducted for ten days, during which spot urine collections were performed every 6 h post feeding on days 9 and 10. The daily urinary excretion of allantoin (A) and purine derivatives (PD) decreased with the reduction in feed intake while creatinine (C) excretion remained similar in animals fed at different levels. The microbial nitrogen (MN) supply calculated from the PD excreted in total urine (35.08 to 72.08 g/d) was higher at increased levels of feed intake. PD concentration in spot urine samples had poor correlation with feed intake except at 12 h post feeding. A/C ratio and PD/C ratio in spot urine samples remained similar irrespective of sampling time and significantly (p<0.01) correlated with daily urinary PD excretion, digestible organic matter intake and dry matter (DM) intake. However, no significant differences were evident in these ratios among animals fed at levels 120, 100 and 80% of voluntary dry matter intake (VDMI) at different times post feeding. These results suggests that the spot urine sampling technique to predict the microbial protein supply is not suitable for detecting small differences in MN supply and hence, estimation of PD excreted in total urine (mmol/d) is necessary to assess precisely the MN supply in crossbred bulls.

• Asian-Australasian Journal of Animal Sciences
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• 제19권6호
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• pp.857-864
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• 2006

The aim of this study was to apply the Cornell net carbohydrate and protein system (CNCPS) in subtropical Taiwan. This was done by means of 3 trials, viz, in situ, lactation and metabolic trials, the latter using the urinary purine derivatives (UPD) to estimate the ruminal microbial yield. Dietary treatments were formulated according to different nutrient requirement systems including, (1) a control NRC78 group on NRC (1978), (2) a NRC88 group on NRC (1988), and (3) a CNCPS group on Cornell Net carbohydrate and protein system model. Results from the lactation trial showed that DM intake (DMI) was higher (p<0.05) in the NRC78 than the other treatment groups. The treatments did not significantly influence milk yield, but milk yield after covariance adjustment for DMI was higher in the CNCPS group (p<0.05). The FCM, milk fat content and yield were greater in both the NRC78 and the NRC88 group over the CNCPS group (p<0.05). The treatments did not significantly influence the DMI adjusted FCM. The solid-non-fat and milk protein contents were higher in the CNCPS group (p<0.05) with or without DMI covariance adjustment. Lactating efficiency was higher in the CNCPS group (p<0.05) compared to the other groups. The significantly lowest milk urea-N (MUN) with better protein utilization efficiency in the CNCPS group (p<0.05) suggested that less N would be excreted into the environment. Cows in the CNCPS group excreted significantly more and the NRC88 group significantly less urinary purine derivatives (UPD) implying that more ruminal microbial protein was synthesized in the CNCPS over the NRC88 group. The CNCPS could become the most useful tool in predicting the trends in milk yield, microbial yield and MUN.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.904-907
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• 1999

The experiment was aimed at studying the effect of ruminal $NH_3-N$ levels on ruminal fermentation, microbial population, urinary purine derivative excretion, digestibility and rice straw intake in swamp buffaloes. Five, 3 to 4 years old, rumen fistulated swamp buffaloes were randomly assigned according to a $5{\times}5$ Latin square design to rceive five different intraruminal infusions of $NH_4HCO_3$ (0, 150, 300, 450 and 600 g/d) on a continuous daily basis. Rice straw as a roughage was offered ad libitum while concentrate was given at 0.8% BW daily. The results were that as levels of $NH_4HCO_3$ increased, ruminal $NH_3-N$ concentrations increased from 7.1 to 34.4 mg%. The highest digestibility and voluntary straw intakes were found at 13.6 to 17.6 mg% ruminal $NH_3-N$ levels; straw intake was highest at 13.6 mg%. Total bacterial and protozoal counts linearly increased as the ruminal $NH_3-N$ increased and were highest at 17.6 mg%. Total urinary purine derivatives and allantoin excretion were highest (44.0, 37.4 mM/d) at 17.6 mg% ruminal $NH_3-N$. Highest total VFAs (115 mM) were obtained a 13.6 mg% ruminal $NH_3-N$ while blood urea nitrogen significantly increased as ruminal $NH_3-N$ increased. The results from this experiment suggest that optimum ruminal $NH_3-N$ in swamp buffaloes is higher than 13.6 mg%, for improving rumen ecology, microbial protein synthesis, digestibility and straw intake.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.479-482
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• 2005

The nutritional worth of Sarson Saag Waste (SSW), a cannery waste, was assessed in comparison with conventional complete diet as a total mixed ration (TMR), and a conventional green fodder, Avena sativa. Each diet was offered ad libitum, supplemented with mineral mixture and common salt, to 4 male murrah buffaloes. The control TMR was made iso-nitrogenous to SSW. Simultaneously, each diet was offered to 3 rumen fistulated male buffaloes for assessing the biochemical changes in the rumen. The nutrient digestibility of unconventional SSW was comparable to that of conventional green fodder-A. sativa but significantly (p<0.05) higher than that of control TMR. The tri-chloro acetic acid (TCA) precipitable-N in the strained rumen liquor of animals fed SSW was considerably higher than that of animals fed A.sativa. The urinary excretion of total purine derivatives was comparable in animals fed SSW and conventional green fodder but significantly (p<0.05) higher than those fed conventional control TMR. The significantly (p<0.05) lower purine nitrogen index (PNI) in animals fed control TMR resulted in significantly (p<0.05) lower microbial protein synthesis than that in animals fed SSW and conventional green fodder. The N-excretion as per cent of nitrogen intake was significantly (p<0.05) lower in animals fed SSW as compared to either of the conventional feeds tested, resulting in significantly (p<0.05) higher Nretention and apparent biological value. SSW supplemented with mineral mixture could serve as an excellent source of nutrients for ruminants.

• Asian-Australasian Journal of Animal Sciences
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• 제25권8호
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• pp.1124-1131
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• 2012

Four Thai - rumen fistulated male swamp buffaloes (Bubalus bubalis), about four years old with $400{\pm}20kg$ liveweight, were randomly assigned according to a $4{\times}4$ Latin square design to receive dietary treatments. The treatments were: ground corn cob (GCC) replacement for cassava chip (CC) in concentrate at 0% (T1); GCC replacement at 33% (T2); GCC replacement at 67% (T3); and GCC replacement at 100% (T4), respectively. During the experiment, concentrate was offered at 0.5% BW while 5% urea-treated rice straw was given at ad libitum. The result revealed that there was no effect of GCC replacement on DMI among treatments. In addition, digestibilities of DM, OM and CP were not different while aNDF linearly increased with an increasing level of GCC replacement. However, GCC replacement did not affect rumen fermentation such as ruminal pH, $NH_3$-N and VFA concentration; except C3 proportion which was the highest at 33% replacement while the lowest was at 100% replacement. All replacements of GCC resulted in similar protozoal and bacterial populations and microbial protein synthesis (MPS). Purine derivatives (PD) concentration in urine and PD to creatinine (PDC) index were varied with time of urination and among treatments at 0 to 8 and 8 to 16 h post feeding and higher values were shown among the GCC replacement groups. However at 16 to 24 h-post feeding, it was untraceable. In addition, creatinine concentration was similar among all treatments at every sampling time. Based on the above results, GCC can be used as an energy source for swamp buffalo fed with rice straw. Spot sampling of urine can be used for purine derivatives determination.