Causes of differences in urinary excretion of purine derivatives in buffaloes and cattle

(http://journals.cambridge.org/action/displayIssue?iid=779256)
(http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=779404&fulltextType=RA&fileId=S1357729806000439)

Vo Thi Kim Thanh^a1 and E. R. Ørskov^a2 c1

^a1 Hue University of Agriculture and Forestry, 102 Phung Hung, Hue, Vietnam
^a2 Macaulay Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK

Abstract

In experiment 1, three male calves of Vietnamese cattle and three maleVietnamese swamp buffalo calves were weaned after receiving colostrum and reared by bottle feeding of milk. During the 1st month the animal did not have access to solid food. Urine was collected to determine differences in endogenous excretion of purine between the two types of animal. After that they were given access to equal amount of solid food for 2 months to stimulate rumen development, urine was again collected to determine the differences in purine excretion. In experiment 2, the same animals were given milk mixed with purines in three treatments (0, 1·7 and 3·4 g/day). The same animals were used in experiment 3 for intravenous allantoin infusion, to test the effect of purines themselves introduced into the plasma.The results showed that in period 1 of experiment 1 there was no significant difference in purine excretion between the two types of animal. The excretion being 0·65 mmol/kg M ^0·75 for cattle and 0·69 mmol/kg M ^0·75for buffaloes calves, respectively. For period 2, after rumen development there were significant differences between two types of animal. The excretion from buffaloes (0·26 mmol/kg M^0·75) being less than half that of cattle (0·69 mmol/kg M ^0·75).In experiment 2 the regression of purine excretion mmol/day (y) was y=0·6279x+9·1496 for cattle calves and y=0·2618x+5·8594 for buffalo calves where x was the purine given.In experiment 3, from each mmol of allantoin infusion, the recovery was about 0·70 in cattle but only half (0·32) in buffaloes ( P<0·01).It is clearly shown that the difference in purine derivative excretion occur only after rumen development It is suggested that glomerular filtration rate may be lower in buffaloes than cattle leaving more time in the blood thus more time for recycling to the rumen and metabolized by bacteria or the permeability from the blood to the rumen is greater in buffaloes than cattle.

(Received July 07 2005)

(Accepted December 29 2005)

Key words

• buffaloes;
• cattle;
• purines;
• rumen