Chiang Mai Journal of Science

Four swamp buffaloes and four Kedah-Kelantan (KK) cattle of similar sex and age were used to study the response of urinary purine derivatives (PD) excretion to feed intake. The animals were fed a diet consisted of 40% oil plam frond (OPF) and 60% concentrates, calculated based on 40, 60, 80 and 95% of the "ad libtum intake" of each species. A double 4 x 4 Latin Square (one for each species) was used for the experiment. Urinary excretion of PD in both species responded linearly to feed intake levels (P<0.001). The totla urinary PD excretion were 0.51 to 0.72 mmol/kg^0.75/day for buffaloes and 0.84 to 1.2 mmol/kg^0.75/day for cattle. The increase in PD excretion per unit digestible organic matter intake (DOMI) for buffaloes was lower than for cattle (8.2 and 15.5 mmol PD/day, respectively). The creatinine excretion for buffaloes remained constant with increasing feeding levels while that for cattle increased significantly with increasing feeding levels (P<0.05). The mean of daily creatinine excretion for buffalo was marginally higher than that of cattle (1.07 and 0.98 mmol/kg^0.75/day, resspectively). Glomerular filtration rate (GFR) did not response to feeding levels for both species. On average GFR for buffaloes (414 l/day) was higher than for cattle (288 l/day). The increment in tubular load (TL) of allantoin for buffaloes was linearly related to levels of feeding (P<0.05). The TL of uric acid, Reabsorption (RB) of allantoin and uric acid did not significantly responsed tofeed intake levels.